Energy Conservation Building Code

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About ECBC

1. Purpose

In accordance with section 14(p) of the Energy Conservation Act 2001 the purpose of the Energy Conservation Building Code (Code) is to provide minimum requirements for the energy-efficient design and construction of buildings. The Code also provides two additional sets of incremental requirements for buildings to achieve enhanced levels of energy efficiency that go beyond the minimum requirements.

2. Scope

The code is applicable to buildings or building complexes that have a connected load of 100 kW or greater or a contract demand of 120 kVA or greater and are intended to be used for commercial purposes.

Buildings intended for private residential purposes only are not covered by the Code.

This code would become mandatory as and when it is notified by the central or state government in the official Gazette under clause (p) of Section 14 or clause (a) of Section 15 of the Energy Conservation Act 2001 (52 of 2001).

2.1 Energy Efficiency Performance Levels

The code prescribes the following three levels of energy efficiency:

  1. Energy Conservation Building Code Compliant Building (ECBC Building)

    ECBC Buildings shall demonstrate compliance by adopting the mandatory and prescriptive requirements listed under ECBC Compliant Building requirements in §4 to §7, or by following the provisions of the Whole Building Performance (WBP) Method in §9.

  2. Energy Conservation Building Code Plus Building (ECBC+ Building)

    ECBC+ Buildings shall demonstrate compliance by adopting the mandatory and prescriptive requirements listed under ECBC+ Compliant Building requirements in §4 to §7, or by following the provisions of the Whole Building Performance (WBP) Method in §9.

  3. Super Energy Conservation Building Code Building (SuperECBC Building)

    SuperECBC Buildings shall demonstrate compliance by adopting the mandatory and prescriptive requirements listed under SuperECBC Compliant Building requirements in §4 to §7, or by following the provisions of the Whole Building Performance (WBP) Method in §9.

2.2 Building Systems

The provisions of this code apply to:

  1. Building envelope,
  2. Mechanical systems and equipment, including heating, ventilating, and air conditioning, service hot water heating,
  3. Interior and exterior lighting, and
  4. Electrical power and motors, and renewable energy systems.

The provisions of this code do not apply to plug loads, and equipment and parts of buildings that use energy for manufacturing processes, unless otherwise specified in the Code.

2.3 Precedence

The following codes, programs, and policies will take precedence over the Code in case of conflict:

  1. Any policy notified as taking precedence over this Code, or any other rules on safety, security, health, or environment by Central, State, or Local Government.
  2. Bureau of Energy Efficiency’s Standards and Labelling for appliances and Star Rating Program for buildings, provided both or either are more stringent than the requirements of this Code.

2.4 Reference Standards

The National Building Code of India 2016 (NBC) is the reference standard for lighting levels, heating, ventilating, and air conditioning (HVAC), thermal comfort conditions, natural ventilation, and any other building materials and system design criteria addressed in this Code.

2.5 Building Classification

Any one or more building or part of a building with commercial use is classified as per the functional requirements of its design, construction, and use. The key classification is as below:

  1. Hospitality: Any building in which sleeping accommodation is provided for commercial purposes, except any building classified under Health Care. Buildings and structures under Hospitality shall include the following:
    1. No-star Hotels – like Lodging-houses, dormitories, no-star hotels/motels
    2. Resort
    3. Star Hotel
  2. Health Care: Any building or part thereof, which is used for purposes such as medical or other treatment or care of persons suffering from physical or mental illness, disease, or infirmity; care of infants, convalescents, or aged persons, and for penal or correctional detention in which the liberty of the inmates is restricted. Health Care buildings ordinarily provide sleeping accommodation for the occupants. Buildings and structures like hospitals, sanatoria, out-patient healthcare, laboratories, research establishments, and test houses are included under this type.
  3. Assembly: Any building or part of a building, where number of persons congregate or gather for amusement, recreation, social, religious, patriotic, civil, travel and similar purposes. Buildings like theatres or motion picture halls, gathering halls, and transport buildings like airports, railway stations, bus stations, and underground and elevated mass rapid transit system are included in this group.
  4. Business: Any building or part thereof which is used for transaction of business, for keeping of accounts and records and similar purposes, professional establishments, and service facilities. There are two subcategories under Business – Daytime Business and 24-hour Business. Unless otherwise mentioned, Business buildings shall include both Daytime and 24-hour subcategories.
  5. Educational: Any building used for schools, colleges, universities, and other training institutions for day-care purposes involving assembly for instruction, education, or recreation for students. If residential accommodation is provided in the schools, colleges, or universities or coaching/ training institution, that portion of occupancy shall be classified as a No-star Hotel. Buildings and structures under Educational shall include following types-
    1. Schools
    2. All other types of institutes, college, university, training institutes etc.
  6. Shopping Complex: Any building or part thereof, which is used as shops, stores, market, for display and sale of merchandise, either wholesale or retail. Buildings like shopping malls, stand-alone retails, open gallery malls, super markets, or hyper markets are included in this type.
  7. Mixed-use Building: In a mixed-use building, each commercial part of a building must be classified separately, and –
    1. If a part of the mixed-use building has different classification and is less than 10% of the total above grade floor area, the mixed-use building shall show compliance based on the building sub-classification having higher percentage of above grade floor area.
    2. If a part of the mixed-use building has different classification and one or more sub-classification is more than 10% of the total above grade floor area, the compliance requirements for each sub-classification, having area more than 10% of above grade floor area of a mixed-use building shall be determined by the requirements for the respective building classification in §4 to §7.

Any building which does not fall under any of the categories defined above shall be classified in a category mentioned above that best describes the function of the building.

3. Compliance & Approach

3.1 General

To comply with the Code, buildings shall

  1. have an Energy Performance Index Ratio (EPI Ratio) as defined in §3.1.1 that is less than or equal to 1
  2. and,
  3. meet all mandatory requirements mentioned under §4.2, §5.2 , §6.2, and §7.2..

3.1.1 Energy Performance Index

The Energy Performance Index (EPI) of a building is its annual energy consumption in kilowatt-hours per square meter of the building. While calculating the EPI of a building, the area of unconditioned basements shall not be included. EPI can be determined by:

EPI = (annual energy consumption in kWh)/(total built-up area (excluding unconditioned basements))

To comply with the Code, EPI value shall be rounded off to two decimal places in accordance with IS 2: 1960 'Rules for rounding off numerical values'.

3.1.2 Determining EPI Ratio

The EPI Ratio of a building is the ratio of the EPI of the Proposed Building to the EPI of the Standard Building:

EPI Ratio = (EPI of Proposed Building)/(EPI of Standard Building)

where,

Proposed Building is consistent with the actual design of the building, and complies with all the mandatory requirements of ECBC.

Standard Building is a standardized building that has the same building floor area, gross wall area and gross roof area as the Proposed Building, complies with the mandatory requirements §4.2, §5.2, §6.2, and §7.2, and minimally complies with prescriptive requirements of §4.3, §5.3, and §6.3 for ECBC Buildings.

The EPI of the Proposed Building shall be established through any one of the following two methods described in §3.2

  1. Prescriptive Method (see §3.2.2)
  2. Whole Building Performance Method (see §3.2.3)

3.1.3 EPI Ratio for Core and Shell Buildings

EPI for core and shell buildings shall be calculated for the entire building based on the final design of the common areas and the relevant mandatory undertaking(s) in the tenant lease agreement for the leased areas, as per §3.2.2.1 or §3.2.3.1.

3.1.4 EPI Ratio for Mixed-use Development

In a mixed-use building, each commercial part of a building must be classified separately, and EPI Ratio shall be calculated separately for each sub-classification, as per §3.2.2.1 or §3.2.3.1. The EPI Ratio of a mixed-use Proposed Building shall be calculated based on area-weighted average method. To calculate the reference maximum design EPI Ratio, listed in Table 9-5 through Table 9-9, applicable for the mixed-use building, each commercial part of mixed-use building shall be classified separately, and,

  1. If a part of the mixed-use building has different classification and is less than 10% of the total above grade area (AGA), the EPI Ratio of the mixed-use Proposed Building shall be less than or equal to Maximum Allowed EPI ratio listed in Table 9-5 through Table 9-9 , for the building sub-classification having highest percentage of above grade floor area.
  2. If a part of the mixed-use building has different classification and is more than 10% of the total above grade floor area, the EPI ratio of the mixed-use Proposed Building shall be less than or equal to Maximum Allowed EPI ratio for compliance calculated based on area weighted average method for all building sub-classifications listed in Table 9-5 through Table 9-9.

Exceptions to the above: Any portion of a mixed-use building classified in a category which does not fall under the scope of ECBC is exempted from demonstrating compliance.

3.2 Compliance Approaches

Buildings that fall within the scope of the Code as mentioned in §2, shall comply with the Code by meeting all the mandatory requirements (see §3.2.1) and any of the compliance paths mentioned in §3.2.2 or §3.2.3.

3.2.1 Mandatory Requirements

Buildings shall comply with all mandatory requirements mentioned under §4.2, §5.2, §6.2, and §7.2, irrespective of the compliance path.

3.2.2 Prescriptive Method

A building complies with the Code using the Prescriptive Method if it meets the prescribed minimum (or maximum) values for envelope components ( §4.3), comfort systems and controls (§5.3, §5.3.12, §5.3.13), and lighting and controls (§6.3), in addition to meeting all the mandatory requirements.

3.2.2.1 EPI Ratio through Prescriptive Method

ECBC Buildings that demonstrate compliance through the Prescriptive Method (§3.2.2) shall be deemed to have an EPI equal to the Standard Building EPI, and therefore an EPI Ratio of 1. ECBC+ Buildings and SuperECBC Buildings that demonstrate compliance through the Prescriptive Method shall be deemed to have an EPI Ratio equal to the EPI Ratios listed in §9.5 under the applicable building type and climate zone.

3.2.2.2 Building Envelope Trade-off Method

To comply with the Prescriptive Method of Section §4, the Building Envelope Trade-off Method may be used in place of the prescriptive criteria of §4.3.1, §4.3.2 and §4.3.3. A building complies with the Code using the Building Envelope Trade-off Method if the Envelope Performance Factor (EPF) of the Proposed Building is less than or equal to the EPF of the Standard Building, calculated as per §4.3.5.

3.2.2.3 Total System Efficiency Method

For projects using central chilled water plants, the Total System Efficiency approach may be used to comply with the Prescriptive Method of §5. This approach may be used in place of the prescriptive criteria of chillers (§5.3.1 and §5.3.6), chilled water pumps (§5.3.2), condenser water pumps (§5.3.2), and cooling tower fan (§5.3.3). Per this approach, a building complies if the Total System Efficiency thresholds are met as per Table 5-23 Maximum System Efficiency Threshold for ECBC, ECBC+, and SuperECBC Buildings. Compliance with other prescriptive requirements (§5.3), as applicable, shall be met with

3.2.2.4 Low Energy Comfort Systems

Low Energy Comfort Systems (§5.3.13) is a simplified approach that provides projects using Low Energy Comfort Systems an opportunity to achieve improved compliance levels of ECBC+ and SuperECBC. This approach is applicable to Prescriptive Method of Section §5. In addition to compliance with the applicable prescriptive requirements (§5.3), the projects must meet the sum of cooling and heating requirement using approved list of low energy systems as per requirements in §5.3.13.

3.2.3 Whole Building Performance Method

A building complies with the Code using the Whole Building Performance (WBP) Method when the estimated annual energy use of the Proposed Design is less than that of the Standard Design, even though it may not comply with the specific provisions of the prescriptive requirements in §4 trough §7. The mandatory requirements of §4 through §7 (§4.2, §5.2, §6.2, and §7.2) shall be met when using the WBP Method.

3.2.3.1 EPI Ratio through Whole Building Performance Method

The EPI of buildings that demonstrate compliance through Whole Building Performance Method (§3.2.3) shall be calculated using the compliance path defined in §3.1.1 and detailed in §9. The EPI Ratio of a building that uses the Whole Building Performance Method to show compliance, should be less than or equal to the EPI Ratio listed in §9.5 for the applicable building type and climate zone.

3.3 Compliance Requirements

3.3.1 New Building Compliance

3.3.1.1 Full building Compliance

New buildings with completed fit-outs shall comply with either the provisions of §3.2.1 and either the provision of §3.2.2 or §3.2.3.

3.3.1.2 Core and Shell building Compliance

New core and shell building shall comply with the provisions of §3.2.1 and either the provision of §3.2.2 or §3.2.3 following base building systems in the common areas:

  1. Building envelope
  2. Thermal comfort systems and controls (only those installed by developer/ owner)
  3. Lighting systems and controls (only those installed by developer/ owner)
  4. Electrical systems (installed by developer/ owner)
  5. Renewable energy systems

Additionally, the tenant lease agreement shall have a legal undertaking clause to ensure interior fit-outs made by tenant shall be Code compliant. The legal undertaking shall mandate the relevant energy efficiency compliance requirements in accordance with the provisions of §3.2.1 and §3.2.2 for all interior fit-outs within the tenant leased area,

3.3.2 Additions and Alterations to Existing Buildings

If any existing building after additions or alterations changes its connected load to 100 kilo-Watt (kW) or above or a contract demand of 120 kilo-Volt Ampere (kVA) or above shall comply with the provisions of §4 through §7. Compliance may be demonstrated in either of the following ways:

  1. The addition shall comply with the applicable requirements, or
  2. The addition, together with the entire existing building, shall comply with the requirements of this Code that shall apply to the entire building, as if it were a new building.

Exceptions to §3.3.2:

When space conditioning is provided by existing systems and equipment, the existing systems and equipment need not comply with this code. However, any new equipment installed must comply with specific requirements applicable to that equipment.

3.4 Approved Compliance Tools

A building following the whole building performance method of §9 or Total System Efficiency – Alternate compliance approach of §5_3_12 shall show compliance through online BEP-EMIS or whole building energy simulation software endorsed by BEE.

Compliance to the daylight requirements of §4.2.3, if calculated through software tools, shall be shown through online BEP-EMIS or daylighting software approved by BEE.

3.5 Administrative Requirements

Administrative requirements, including but not limited to, permit requirements, enforcement, interpretations, claims of exemption, approved calculation methods, and rights of appeal are specified by the authority having jurisdiction.

3.6 Compliance Documents

3.6.1 Compliance Documents

Construction drawings and specifications shall show all pertinent data and features of the building, equipment, and systems in sufficient detail to permit the authority having jurisdiction to verify that the building complies with the requirements of this code. Details shall include, but are not limited to:

  1. Building Envelope: opaque construction materials and their thermal properties including thermal conductivity, specific heat, density along with thickness;fenestration U-factors, solar heat gain coefficients (SHGC), visible light transmittance (VLT) and building envelope sealing documentation; overhangs and side fins, building envelope sealing details;
  2. Heating, Ventilation, and Air Conditioning: system and equipment types, sizes, efficiencies, and controls; economizers; variable speed drives; piping insulation; duct sealing, insulation and location; solar water heating system; requirement for balance report;
  3. Lighting: lighting schedule showing type, number, and wattage of lamps and ballasts; automatic lighting shutoff, occupancy sensors, and other lighting controls;lamp efficacy for exterior lamps;
  4. Electrical Power: electric schedule showing transformer losses, motor efficiencies, and power factor correction devices; electric check metering and monitoring system.
  5. Renewable energy systems: system peak generation capacity, technical specifications, solar zone area

3.6.2 Supplemental Information

The authority having jurisdiction may require supplemental information necessary to verify compliance with this code, such as calculations, worksheets, compliance forms, manufacturer’s literature, or other data.

Building Envelope

4.2.1 Fenestration

4.2.1.1 U-Factor

U-factors shall be determined for the overall fenestration product (including the sash and frame) in accordance with ISO-15099 by an accredited independent laboratory, and labeled or certified by the manufacturer. U-factors for sloped glazing and skylights shall be determined at a slope of 20 degrees above the horizontal. For unrated products, use the default table in Appendix A.

4.2.1.2 Solar Heat Gain Coefficient

SHGC shall be determined for the overall single or multi glazed fenestration product (including the sash and frame) in accordance with ISO-15099 by an accredited independent laboratory, and labeled or certified by the manufacturer.

Exceptions to §4.2.1.2:

  1. Shading coefficient (SC) of the center of glass alone multiplied by 0.86 is an acceptable alternate for compliance with the SHGC requirements for the overall fenestration area.
  2. Solar heat gain coefficient (SHGC) of the glass alone is an acceptable alternate for compliance with the SHGC requirements for the overall fenestration product.

4.2.1.3 Visual Light Transmittance

Visible light transmittance (VLT) shall be determined for the fenestration product in accordance with ISO-15099 by an accredited independent laboratory, and labeled or certified by the manufacturer. For unrated products, VLT of the glass alone shall be de-rate by 10% for demonstrating compliance with the VLT requirements for the overall fenestration product. 

4.2.2 Opaque Construction

4.2.2.1 U-Factor

U-factors shall be calculated for the opaque construction in accordance with ISO-6946. Testing shall be done in accordance with approved ISO Standard for respective insulation type by an accredited independent laboratory, and labeled or certified by the manufacturer. For unrated products, use the default tables in Appendix A.

4.2.2.2 Solar Reflectance

Solar reflectance for the external opaque roof construction shall be determined in accordance with ASTM E903-96 by an accredited independent laboratory, and labeled or certified by the manufacturer.

4.2.2.3 Emittance

Emittance for the external opaque roof construction shall be determined in accordance with ASTM E408-71 (RA 1996) by an accredited independent laboratory, and labeled or certified by the manufacturer.

4.2.3 Daylighting

Above grade floor areas shall meet or exceed the useful daylight illuminance (UDI) area requirements listed in Table 4-1 for 90% of the potential daylit time in a year. Mixed-use buildings shall show compliance as per the criteria prescribed in §2.5. Compliance shall be demonstrated either through daylighting simulation method in §4.2.3.1 or the manual method in §4.2.3.2 . Assembly buildings and other buildings where daylighting will interfere with the functions or processes of 50% (or more) of the building floor area, are exempted from meeting the requirements listed in Table 4-1.

Exceptions to §4.2.3:

Assembly buildings and other buildings where daylighting will interfere with the functions or processes of 50% (or more) of the building floor area, are exempted from meeting the requirements listed in Table 4-1.

Table 4-1 Daylight Requirement
Building Category Percentage of above grade floor area meeting the UDI requirement
ECBC ECBC+ SuperECBC
Business, Educational 40% 50% 60%
No Star Hotel, Star Hotel, Healthcare 30% 40% 50%
Resort 45% 55% 65%
Shopping Complex 10% 15% 20%
Assembly Exempted

4.2.3.1 Daylighting Simulation Method

Only BEE approved software shall be used to demonstrate compliance through the daylighting simulation method. Buildings shall achieve illuminance level between 100 lux and 2,000 lux for the minimum percentage of floor area prescribed in Table 4-1 for at least 90% of the potential daylit time. Illuminance levels for all spaces enclosed by permanent internal partitions (opaque, translucent, or transparent) with height greater or equal to 2 m from the finished floor, shall be measured as follows:

  1. Measurements shall be taken at a work plane height of 0.8 m above the finished floor.
  2. The period of analysis shall be fixed for continuously 8 hours per day, anytime between 7:00 AM IST to 5:00 PM IST, resulting in 2,920 hours in total for all building types except for Schools. Schools shall be analyzed for continuously 7 hours per day, anytime between 7:00 AM IST to 3:00 PM IST.
  3. Available useful daylight across a space shall be measured based on point-by-point grid values. UDI shall be calculated for at least one point for each square meter of floor area.
  4. Fenestration shall be modeled with actual visible light transmission (VLT) as per the details provided in the material specification sheet.
  5. All surrounding natural or man-made daylight obstructions shall be modeled if the distance between the facade of the building (for which compliance is shown) and surrounding natural or man-made daylight obstructions is less than or equal to twice the height of the man-made or natural sunlight obstructers. If the reflectance of the surfaces is not known, default reflectance of 30% and 0% shall be used for all vertical surfaces of man-made and natural obstructers respectively.
  6. Interior surface reflectance shall be modeled based on the actual material specification. If material specification is not available, the default values in Table 4-2 shall be used:
  7. Documentation requirement to demonstrate compliance are:
    1. Brief description of the project with location, number of stories, space types, hours of operation and and software used.
    2. Summary describing the results of the analysis and output file from simulation tool outlining point wise compliance for the analysis grid and compliance in percentage.
    3. Explanation of any significant modelling assumptions made.
    4. Explanation of any error messages noted in the simulation program output.
    5. Building floor plans, building elevations & sections, and site plan with surrounding building details (if modeled).
    6. Material reflectance, analysis grid size, total number of grid size/resolution, total number of grid points.
Table 4-2 Default Values for Surface Reflectance
Surface Type Reflectance
Wall or Vertical Internal Surfaces 50%
Ceiling 70%
Floor 20%
Furniture (permanent) 50%

4.2.3.2 Manual Daylighting Compliance Method

This method can be used for demonstrating compliance with daylighting requirements without simulation. Daylight extent factors (DEF) mentioned in Table 4-3 shall be used for manually calculating percentage of above grade floor area meeting the UDI requirement for 90% of the potential daylit time in a year.

Table 4-3 Daylight Extent Factors (DEF) for Manually Calculating Daylight Area
Shading Latitude Window Type VLT < 0.3 VLT ≥ 0.3
N S E W N S E W
No shading or PF < 0.4 ≥15°N All window types 2.5 2.0 0.7 0.5 2.8 2.2 1.1 0.7
< 15°N 2.4 2.0 0.8 0.6 2.7 2.2 1.5 0.8
Shading with PF ≥ 0.4 All latitudes All window types without light shelf* 2.8 2.3 1.5 1.1 3.0 2.5 1.8 1.5
Window with light shelf* 3.0 2.5 1.8 1.6 3.5 3.0 2.1 1.8
* To qualify as light shelf the internal projection shall meet the requirements specified under Exceptions to SHGC requirements in Table 4-10 and Table 4-11 (w)
  1. To calculate the daylit area:
    1. In a direction perpendicular to the fenestration, multiply daylight extent factor (DEF) by the head height of the fenestration or till an opaque partition higher than head height of the fenestration, whichever is less.
    2. In the direction parallel to the fenestration, daylit area extends a horizontal dimension equal to the width of the fenestration plus either 1 meter on each side of the aperture, or the distance to an opaque partition of 2 m high, or one-half the distance to an adjacent fenestration, whichever is least.
    3. For skylights, calculate the horizontal dimension in each direction equal to the top aperture dimension in that direction plus either the floor-to-ceiling height (H) for skylights, or 1.5 H for monitors, or H or 2H for the sawtooth configuration, or the distance to the nearest 1 meter or higher opaque partition, or one-half the distance to an adjacent skylight or vertical glazing, whichever is least.
    4. Glazed façades, with non-cardinal orientation, shall be categorized under a particular cardinal direction if its orientation is within ± 45 degrees of that cardinal direction.
    5. Daylit area overlap: For overlapping daylit areas such as windows on different orientations or in case of skylights the overlapping daylit area shall be subtracted from the sum of daylit area.
  2. Documentation requirement:
    1. A separate architectural plan shall be prepared with all daylit areas marked on the floor plans.
    2. A summary shall be provided showing compliance as per Table 4-1.

4.2.4 Building Envelope Sealing

Following areas of the building envelope, of all except naturally ventilated buildings or spaces, shall be sealed, caulked, gasketed, or weather-stripped:

  1. Joints around fenestration, skylights, and door frames
  2. Openings between walls and foundations, and between walls and roof, and wall panels
  3. Openings at penetrations of utility services through roofs, walls, and floors
  4. Site-built fenestration and doors
  5. Building assemblies used as ducts or plenums
  6. All other openings in the building envelope
  7. Exhaust fans shall be fitted with a sealing device such as a self-closing damper
  8. Operable fenestration should be constructed to eliminate air leakages from fenestration frame and shutter frame

4.3.1 Roof

Roofs shall comply with the maximum assembly U-factors in Table 4-4 through Table 4-6. The roof insulation shall be applied externally as part of the roof assembly and not as a part of false ceiling.

Table 4-4 Roof Assembly U-factor (W/m2.K) Requirements for ECBC Compliant Building
Composite Hot and dry Warm and humid Temperate Cold
All building types, except below 0.33 0.33 0.33 0.33 0.28
School <10,000 m2 AGA 0.47 0.47 0.47 0.47 0.33
Hospitality > 10,000 m2 AGA 0.20 0.20 0.20 0.20 0.20
Table 4-5 Roof Assembly U-factor (W/m2.K) Requirements for ECBC+ Compliant Building
Composite Hot and dry Warm and humid Temperate Cold
Hospitality,
Healthcare
Assembly
0.20 0.20 0.20 0.20 0.20
Business
Educational
Shopping Complex
0.26 0.26 0.26 0.26 0.20
Table 4-6 Roof Assembly U-factor (W/m2.K) Requirements for SuperECBC Building
Composite Hot and dry Warm and humid Temperate Cold
All buildings types 0.20 0.20 0.20 0.20 0.20

4.3.1.1 Vegetated and Cool Roof

All roofs that are not covered by solar photovoltaics, or solar hot water, or any other renewable energy system, or utilities and services that render it unsuitable for the purpose, shall be either cool roofs or vegetated roofs.

  1. For qualifying as a cool roof, roofs with slopes less than 20° shall have an initial solar reflectance of no less than 0.70 and an initial emittance no less than 0.75. Solar reflectance shall be determined in accordance with ASTM E903-96 and emittance shall be determined in accordance with ASTM E408-71 (RA 1996).
  2. For qualifying as a vegetated roof, roof areas shall be covered by living vegetation of >50 mm high.

4.3.2 Opaque External Wall

Opaque above grade external walls shall comply with the maximum assembly U-factors in Table 4-7 through Table 4-9.

Table 4-7 Opaque Assembly Maximum U-factor (W/m2.K) Requirements for a ECBC compliant Building
Composite Hot and dry Warm and humid Temperate Cold
All building types, except below 0.40 0.40 0.40 0.55 0.34
No Star Hotel < 10,000 m2 AGA 0.63 0.63 0.63 0.63 0.40
Business < 10,000 m2 AGA 0.63 0.63 0.63 0.63 0.40
School <10,000 m2 AGA 0.85 0.85 0.85 1.00 0.40
Table 4-8 Opaque Assembly Maximum U-factor (W/m2.K) Requirements for ECBC+ Compliant Building
Composite Hot and dry Warm and humid Temperate Cold
All building types, except below 0.34 0.34 0.34 0.55 0.22
No Star Hotel < 10,000 m2 AGA 0.44 0.44 0.44 0.44 0.34
Business < 10,000 m2 AGA 0.44 0.44 0.44 0.55 0.34
School < 10,000 m2 AGA 0.63 0.63 0.63 0.75 0.44
Table 4-9 Opaque Assembly Maximum U-factor (W/m2.K) Requirements for SuperECBC Building
Composite Hot and dry Warm and humid Temperate Cold
All building types 0.22 0.22 0.22 0.22 0.22

Exceptions to §4.3.2: Opaque external walls of an unconditioned building of No Star Hotel, Healthcare, and School categories in all climatic zones, except for cold climatic zone, shall have a maximum assembly U-factor of 0.8 W/m2.K.

4.3.3 Vertical Fenestration

For all climatic zones, vertical fenestration compliance requirements for all three energy efficiency levels, i.e. ECBC, ECBC+, and SuperECBC, shall comply with the following:

  1. (a) Maximum allowable Window Wall Ratio (WWR) is 40% (applicable to buildings showing compliance using the Prescriptive Method, excluding Building Envelope Trade-off Method)
  2. Minimum allowable Visual Light Transmittance (VLT) is 0.27
  3. Assembly U-factor shall be determined for the overall fenestration product (including the sash and frame)

Vertical fenestration shall comply with the maximum Solar Heat Gain Coefficient (SHGC) and U-factor requirements of Table 4-10 for ECBC buildings and Table 4-11 for ECBC+ buildings and SuperECBC buildings. Vertical fenestration on non-cardinal direction, shall be categorized under a particular cardinal direction if its orientation is within ± 45° of that cardinal direction.

Table 4-10 Vertical Fenestration Assembly U-factor and SHGC Requirements for ECBC Buildings
Composite Hot and dry Warm and humid Temperate Cold
Maximum U-factor (W/m2.K) 3.00 3.00 3.00 3.00 3.00
Maximum SHGC Non-North 0.27 0.27 0.27 0.27 0.62
Maximum SHGC North for latitude ≥ 15°N 0.50 0.50 0.50 0.50 0.62
Maximum SHGC North for latitude < 15°N 0.27 0.27 0.27 0.27 0.62
See Appendix A for default values of unrated fenestration.
Table 4-11 Vertical Fenestration U-factor and SHGC Requirements for ECBC+ buildings and SuperECBC buildings
Composite Hot and dry Warm and humid Temperate Cold
Maximum U-factor (W/m2.K) 2.20 2.20 2.20 3.00 1.80
Maximum SHGC Non-North 0.25 0.25 0.25 0.25 0.62
Maximum SHGC North for latitude ≥ 15°N 0.50 0.50 0.50 0.50 0.62
Maximum SHGC North for latitude < 15°N 0.25 0.25 0.25 0.25 0.62

Exceptions to SHGC requirements in Table 4-10 and Table 4-11:

  1. For fenestration with a permanent external projection, including but not limited to overhangs, side fins, box frame, verandah, balcony, and fixed canopies that provide permanent shading to the fenestration, the equivalent SHGC for the proposed shaded fenestration may be determined as less than or equal to the SHGC requirements of Table 4-10 and Table 4-11. Equivalent SHGC shall be calculated by following the steps listed below:
    1. Projection factor (PF) for the external permanent projection, shall be calculated as per the applicable shading type listed in §8.2. The range of projection factor for using the SEF is 0.25 ≤ PF ≤ 1.0. The SEF is applicable for both side fins shading only other than overhangs. The projection factor shall be calculated for both side fins and the lower projection factor of each fin shall be considered. Other shading devices shall be modeled through the Whole Building Performance Method in §9.
    2. A shaded vertical fenestration on a non-cardinal direction, shall be categorized either under a particular cardinal direction or a primary inter-cardinal direction if its orientation is within the range of ±22.5 degrees of the cardinal or primary inter-cardinal direction.
    3. Any surrounding man-made or natural sunlight obstructers shall be considered as a permanent shading of PF equal to 0.4 if
      1. the distance between the vertical fenestration of the building, for which compliance is shown, and surrounding man-made or natural sunlight obstructers is less than or equal to twice the height of the surrounding man-made or natural sunlight obstructers; and
      2. the surrounding man-made or natural sunlight obstructers shade the façade for at least 80% of the total time that the façade is exposed to direct sun light on a summer solstice. Compliance shall be shown using a sun path analysis for summer solstice for the vertical fenestration.
    4. An equivalent SHGC is calculated by dividing the SHGC of the unshaded fenestration product with a Shading Equivalent Factor (SEF). SEF shall be determined for each orientation and shading device type.
    5. The maximum allowable SHGC is calculated by multiplying the prescriptive SHGC requirement for respective compliance level from Table 4-10 and Table 4-11 with the SEF.
    Table 4-12 Shading Equivalent Factors for Latitudes greater than or equal to 15 ºN
    SEF PF North East South West North-East South-East South-West North-West
    Overhang + Fins 0.25 1.25 1.37 1.58 1.36 1.47 1.47 1.42 1.53
    0.3 1.29 1.48 1.72 1.43 1.54 1.65 1.57 1.58
    0.35 1.34 1.58 1.88 1.51 1.62 1.81 1.73 1.65
    0.4 1.39 1.67 2.06 1.61 1.70 1.97 1.89 1.75
    0.45 1.43 1.76 2.26 1.71 1.78 2.11 2.06 1.87
    0.5 1.47 1.85 2.47 1.83 1.86 2.25 2.23 2.00
    0.55 1.51 1.94 2.69 1.96 1.94 2.38 2.40 2.13
    0.6 1.55 2.03 2.92 2.09 2.02 2.51 2.58 2.27
    0.65 1.59 2.13 3.15 2.24 2.10 2.64 2.76 2.40
    0.7 1.63 2.24 3.18 2.39 2.18 2.77 2.94 2.53
    0.75 1.66 2.37 3.19 2.56 2.25 2.90 3.12 2.64
    0.8 1.70 2.52 3.20 2.72 2.33 3.04 3.18 2.73
    0.85 1.73 2.69 3.21 2.90 2.40 3.11 3.23 2.80
    0.9 1.76 2.89 3.24 3.07 2.46 3.15 3.25 2.84
    0.95 1.79 3.11 3.28 3.25 2.52 3.17 3.27 2.85
    ≥1 1.80 3.30 3.33 3.33 2.57 3.23 3.30 2.82
    Overhang 0.25 1.09 1.21 1.28 1.20 1.17 1.26 1.23 1.20
    0.3 1.11 1.26 1.34 1.27 1.22 1.32 1.27 1.24
    0.35 1.13 1.30 1.39 1.33 1.26 1.39 1.32 1.28
    0.4 1.15 1.35 1.46 1.38 1.30 1.46 1.38 1.32
    0.45 1.16 1.40 1.52 1.43 1.33 1.53 1.46 1.36
    0.5 1.18 1.45 1.59 1.48 1.35 1.60 1.54 1.40
    0.55 1.20 1.51 1.66 1.52 1.38 1.67 1.62 1.44
    0.6 1.21 1.56 1.73 1.57 1.40 1.74 1.70 1.47
    0.65 1.22 1.62 1.81 1.61 1.42 1.81 1.79 1.51
    0.7 1.24 1.68 1.88 1.66 1.45 1.88 1.87 1.55
    0.75 1.25 1.74 1.95 1.72 1.48 1.94 1.94 1.58
    0.8 1.26 1.80 2.02 1.77 1.51 2.00 2.01 1.61
    0.85 1.27 1.86 2.09 1.84 1.56 2.06 2.06 1.64
    0.9 1.28 1.92 2.15 1.91 1.61 2.11 2.10 1.67
    0.95 1.29 1.99 2.21 1.98 1.67 2.15 2.13 1.70
    ≥1 1.30 2.06 2.26 2.07 1.75 2.19 2.14 1.72
    Side Fins 0.25 1.13 1.11 1.18 1.11 1.21 1.14 1.16 1.23
    0.3 1.15 1.13 1.22 1.13 1.22 1.17 1.22 1.27
    0.35 1.17 1.15 1.26 1.15 1.24 1.20 1.26 1.32
    0.4 1.19 1.17 1.29 1.17 1.27 1.23 1.29 1.36
    0.45 1.21 1.19 1.32 1.19 1.30 1.25 1.31 1.41
    0.5 1.22 1.20 1.35 1.20 1.34 1.27 1.33 1.46
    0.55 1.24 1.22 1.38 1.22 1.38 1.29 1.34 1.50
    0.6 1.25 1.23 1.40 1.23 1.42 1.31 1.35 1.55
    0.65 1.27 1.24 1.42 1.25 1.47 1.32 1.36 1.58
    0.7 1.28 1.26 1.44 1.26 1.51 1.34 1.36 1.61
    0.75 1.30 1.27 1.46 1.27 1.55 1.35 1.37 1.64
    0.8 1.31 1.28 1.48 1.29 1.59 1.37 1.38 1.65
    0.85 1.32 1.30 1.49 1.30 1.62 1.38 1.39 1.65
    0.9 1.34 1.31 1.51 1.31 1.65 1.40 1.40 1.64
    0.95 1.35 1.32 1.53 1.32 1.67 1.42 1.42 1.61
    ≥1 1.36 1.33 1.55 1.33 1.69 1.44 1.45 1.57
    Table 4-13 Shading Equivalent Factors for Latitudes less than 15 ºN
    SEF PF North East South West North-East South-East South-West North-West
    Overhang + Fins 0.25 1.38 1.33 1.30 1.34 1.42 1.41 1.37 1.42
    0.3 1.44 1.42 1.35 1.42 1.49 1.46 1.41 1.52
    0.35 1.50 1.50 1.42 1.50 1.57 1.52 1.47 1.63
    0.4 1.56 1.59 1.50 1.59 1.66 1.59 1.54 1.73
    0.45 1.61 1.67 1.59 1.69 1.76 1.67 1.61 1.84
    0.5 1.67 1.76 1.68 1.80 1.87 1.75 1.70 1.94
    0.55 1.72 1.85 1.79 1.90 1.98 1.85 1.80 2.05
    0.6 1.77 1.94 1.89 2.02 2.09 1.94 1.89 2.15
    0.65 1.82 2.02 1.99 2.13 2.20 2.04 2.00 2.25
    0.7 1.86 2.11 2.08 2.24 2.31 2.15 2.10 2.36
    0.75 1.90 2.19 2.17 2.35 2.42 2.25 2.21 2.46
    0.8 1.94 2.28 2.25 2.46 2.53 2.35 2.31 2.55
    0.85 1.98 2.36 2.31 2.56 2.64 2.45 2.42 2.65
    0.9 2.02 2.44 2.35 2.66 2.74 2.54 2.52 2.74
    0.95 2.05 2.51 2.38 2.75 2.84 2.63 2.61 2.83
    ≥1 2.08 2.58 2.38 2.83 2.93 2.71 2.70 2.91
    Overhang 0.25 1.15 1.19 1.09 1.20 1.17 1.08 1.04 1.18
    0.3 1.17 1.23 1.07 1.24 1.22 1.12 1.08 1.21
    0.35 1.20 1.28 1.07 1.29 1.26 1.16 1.12 1.25
    0.4 1.22 1.32 1.07 1.33 1.30 1.19 1.17 1.29
    0.45 1.24 1.37 1.09 1.38 1.33 1.23 1.21 1.32
    0.5 1.26 1.42 1.12 1.42 1.37 1.28 1.25 1.35
    0.55 1.28 1.46 1.15 1.46 1.40 1.32 1.29 1.39
    0.6 1.30 1.51 1.18 1.50 1.43 1.36 1.33 1.42
    0.65 1.32 1.55 1.22 1.55 1.46 1.40 1.37 1.45
    0.7 1.33 1.60 1.26 1.59 1.48 1.43 1.40 1.48
    0.75 1.35 1.64 1.29 1.62 1.51 1.47 1.44 1.50
    0.8 1.37 1.67 1.32 1.66 1.53 1.51 1.47 1.53
    0.85 1.38 1.71 1.35 1.70 1.55 1.54 1.51 1.56
    0.9 1.39 1.74 1.37 1.73 1.57 1.56 1.54 1.58
    0.95 1.40 1.77 1.38 1.77 1.59 1.59 1.56 1.61
    ≥1 1.41 1.79 1.38 1.80 1.61 1.61 1.59 1.63
    Side Fins 0.25 1.17 1.10 1.06 1.10 1.15 1.14 1.16 1.16
    0.3 1.20 1.12 1.11 1.12 1.18 1.18 1.21 1.19
    0.35 1.12 1.13 1.16 1.14 1.21 1.20 1.25 1.22
    0.4 1.26 1.15 1.20 1.15 1.24 1.23 1.29 1.25
    0.45 1.28 1.16 1.23 1.17 1.27 1.25 1.31 1.28
    0.5 1.30 1.18 1.25 1.19 1.30 1.27 1.34 1.30
    0.55 1.32 1.19 1.27 1.20 1.33 1.29 1.36 1.33
    0.6 1.34 1.20 1.29 1.22 1.36 1.31 1.37 1.35
    0.65 1.36 1.21 1.30 1.23 1.38 1.34 1.38 1.38
    0.7 1.38 1.22 1.31 1.24 1.41 1.36 1.40 1.40
    0.75 1.40 1.23 1.33 1.26 1.43 1.38 1.41 1.42
    0.8 1.42 1.24 1.34 1.27 1.46 1.41 1.43 1.44
    0.85 1.43 1.25 1.35 1.28 1.48 1.44 1.45 1.47
    0.9 1.45 1.26 1.37 1.29 1.50 1.47 1.47 1.49
    0.95 1.46 1.27 1.39 1.31 1.52 1.50 1.50 1.51
    ≥1 1.47 1.28 1.42 1.32 1.53 1.54 1.53 1.53
  2. Vertical fenestration, located such that its bottom is more than 2.2 m above the level of the floor, is exempt from the SHGC requirements in Table 4-10 and Table 4-11, if the following conditions are complied with:
    1. The Total Effective Aperture (WWR X VLT) for the elevation is less than 0.25, including all fenestration areas more than 1.0 meter above the floor level; and,
    2. An interior light shelf is provided at the bottom of this fenestration area, with a projection factor on interior side not less than:
      1. 1.0 for E-W, SE, SW, NE, and NW orientations
      2. 0.50 for S orientation, and
      3. 0.35 for N orientation when latitude is less than 15°N.

Exceptions to U-factor requirements in Table 4-10 and Table 4-11,

Vertical fenestration on all unconditioned buildings or unconditioned spaces may have a maximum U-factor of 5 W/m2.K provided they comply with all conditions mentioned in Table 4-14.

Table 4-14 U-factor (W/m2.K) Exemption Requirements for Shaded Building
Building Type Climate zone Orientation Maximum Effective SHGC Minimum VLT PF
Unconditioned buildings or unconditioned spaces All except cold Non-North for all latitudes and North for latitude < 15°N 0.27 0.27 ≥0.40
North for latitude ≥ 15°N 0.27 0.27 ≥0.0

4.3.4 Skylights

Skylights shall comply with the maximum U-factor and maximum SHGC requirements of Table 4-15. Skylight roof ratio (SRR), defined as the ratio of the total skylight area of the roof, measured to the outside of the frame, to the gross exterior roof area, is limited to a maximum of 5% for ECBC Building, ECBC+ Building, and SuperECBC Building, when using the Prescriptive Method for compliance.

Table 4-15 Skylight U-factor (W/m2.K) and SHGC Requirements
Climate Maximum U-factor Maximum SHGC
All climatic zones 4.25 0.35

Exception to §4.3.4 Skylights in temporary roof coverings or awnings over unconditioned spaces.

Comfort Systems and Controls

5.2.1 Ventilation*

  1. All habitable spaces shall be ventilated with outdoor air in accordance with the requirements of §5.2.1 and guidelines specified in the National Building Code 2016 (Part 8: Building Services, Section 1: Lighting and Natural Ventilation, Subsection 5: Ventilation).
  2. Ventilated spaces shall be provided with outdoor air using one of the following:
    1. Natural ventilation
    2. Mechanical ventilation

5.2.1.1 Natural Ventilation Design Requirements

Naturally ventilated buildings shall:

  1. Comply with guidelines provided for natural ventilation in NBC.
  2. Have minimum BEE 3-star rated ceiling fans, if provided with ceiling fans.
  3. Have exhaust fans complying with minimum efficiency requirements of fans in §5.3, if provided.

5.2.1.2 Mechanical Ventilation Air Quantity Design Requirements

Buildings that are ventilated using a mechanical ventilation system that are ventilated with a mechanical system, either completely or in conjunction with natural ventilation systems, shall:

  1. Install mechanical systems that provide outdoor air change rate as per NBC.
  2. Have a ventilation system controlled by CO sensors for basement carpark spaces with total car park space greater than or equal to 600 m2.

5.2.1.3 Demand Control Ventilation

Mechanical ventilation systems shall have demand control ventilation if they provide outdoor air greater than 1,500 liters per second, to a space greater than 50 m2, with occupant density exceeding 40 people per 100 m2 of the space, and are served by one or more of the following systems:

  1. An air side economizer
  2. Automatic outdoor modulating control of the outdoor air damper

Exceptions to §5.2.1.3:

  1. Classrooms in Schools, call centers category under Business
  2. Spaces that have processes or operations that generate dust, fumes, mists, vapors, or gases and are provided with exhaust ventilation, such as indoor operation of internal combustion engines or areas designated for unvented food service preparation, or beauty salons
  3. Systems with exhaust air energy recovering system

5.2.2 Minimum Space Conditioning Equipment Efficiencies*

5.2.2.1 Chillers

  1. Chillers shall meet or exceed the minimum efficiency requirements presented in Table 5-1 through Table 5-2 under ANSI/ AHRI 550/ 590 conditions.
  2. The application of air-cooled chiller is allowed in all buildings with cooling load less than 530 kW. For buildings with cooling load equal to or greater than 530 kW, the capacity of air-cooled chiller shall be restricted to 33% of the total installed chilled water capacity unless the authority having jurisdiction mandates the application of air cooled chillers.
  3. Minimum efficiency requirements under BEE Standards and Labeling Program for chillers shall take precedence over the minimum requirements presented in Table 5-1 through Table 5-2.
  4. To show compliance to ECBC, minimum requirement of both COP and IPLV requirement shall be met.
Table 5-1 Minimum Energy Efficiency Requirements for water cooled Chillers
Chiller Capacity (kWr) COP IPLV
<260 4.7 5.8
≥260 & <530 4.9 5.9
≥530 & <1,050 5.4 6.5
≥1,050 & <1,580 5.8 6.8
≥1,580 6.3 7.0
Table 5-2 Minimum Energy Efficiency Requirements for air cooled Chillers
Chiller Capacity (kWr) COP IPLV
<260 2.8 3.5
≥260 3.0 3.7

5.2.2.2 Unitary, Split, Packaged Air-Conditioners

Unitary air-conditioners shall meet or exceed the efficiency requirements given in Table 5-3 through Table 5-5. Window and split air conditioners shall be certified under BEE’s Star Labeling Program. EER shall be as per IS 8148 for all unitary, split, packaged air conditioners greater than 10 kWr.

Table 5-3 Minimum Requirements for Unitary, Split, Packaged Air Conditioners in ECBC Building
Cooling Capacity (kWr) Water Cooled Air Cooled
≤ 10.5 NA BEE 3 Star
> 10.5 3.3 EER 2.8 EER

5.2.2.3 Variable Refrigerant Flow

Variable Refrigerant Flow (VRF) systems shall meet or exceed the efficiency requirements specified in Table 5-4 as per the ANSI/AHRI Standard 1230 while the Indian Standard on VRF is being developed. BEE Standards and Labeling requirements for VRF shall take precedence over the current minimum requirement.

Table 5-4 Minimum Efficiency Requirements for VRF Air conditioners for ECBC Building*
For Heating or cooling or both
Type Size category (kWr) EER (W/W) IEER
VRF Air Conditioners, Air cooled < 40 3.28 4.36
≥ 40 and < 70 3.26 4.34
≥ 70 3.02 4.07
* The revised EER and IEER values as per Indian Standard for VRF corresponding to values in this table will supersede as and when the revised standards are published.

5.2.2.4 Air Conditioning and Condensing Units Serving Computer Rooms

Air conditioning and condensing units serving computer rooms shall meet or exceed the energy efficiency requirements listed in Table 5-5.

Table 5-5 Minimum Efficiency Requirements for Computer Room Air Conditioners
Equipment type Net Sensible Cooling Capacitya Minimum SCOP-127b
Downflow Upflow
All types of computer room ACs Air/ Water/ Glycol All capacity 2.5 2.5
  1. Net Sensible cooling capacity = Total gross cooling capacity - latent cooling capacity – Fan power
  2. Sensible Coefficient of Performance (SCOP-127): A ratio calculated by dividing the net sensible cooling capacity in watts by the total power input in watts (excluding reheater and dehumidifier) at conditions defined in ASHRAE Standard 127-2012 Method of Testing for Rating Computer and Data Processing Room Unitary Air Conditioners)

5.2.2.5 Boilers

Gas and oil fired boilers shall meet or exceed the minimum efficiency requirements specified in Table 5-6.

Table 5-6 Minimum Efficiency Requirements for Oil and Gas Fired Boilers for ECBC building/th>
Equipment Type Sub Category Size Category Minimum FUE
Boilers, Hot Water Gas or oil fired All capacity 80%
FUE - fuel utilization efficiency

5.2.3 Controls*

To comply with the Code, buildings shall meet the requirements of §5.2.3.1 through §5.2.3.5.

5.2.3.1 Timeclock

Mechanical cooling and heating systems in Universities and Training Institutions of all sizes and all Shopping Complexes with built up area greater than 20,000 m2 shall be controlled by timeclocks that:

  1. Can start and stop the system under different schedules for three different day-types per week,
  2. Are capable of retaining programming and time setting during loss of power for a period of at least 10 hours, and
  3. Include an accessible manual override that allows temporary operation of the system for up to 2 hours.

Exceptions to §5.2.3.1:

  1. Cooling systems less than 17.5 kWr
  2. Heating systems less than 5.0 kWr
  3. Unitary systems of all capacities

5.2.3.2 Temperature Controls

Mechanical heating and cooling equipment in all buildings shall be installed with controls to manage the temperature inside the conditioned zones. Each floor or a building block shall be installed with at least one control to manage the temperature. These controls should meet the following requirements:

  1. Where a unit provides both heating and cooling, controls shall be capable of providing a temperature dead band of 3.0°C within which the supply of heating and cooling energy to the zone is shut off or reduced to a minimum.
  2. Where separate heating and cooling equipment serve the same temperature zone, temperature controls shall be interlocked to prevent simultaneous heating and cooling.
  3. Separate thermostat control shall be installed in each
    1. guest room of Resort and Star Hotel,
    2. room less than 30 m2 in Business,
    3. air-conditioned class room, lecture room, and computer room of Educational,
    4. in-patient and out-patient room of Healthcare

5.2.3.3 Occupancy Controls

Occupancy controls shall be installed to de-energize or to throttle to minimum the ventilation and/or air conditioning systems when there are no occupants in:

  1. Each guest room in a Resort and Star Hotel
  2. Each public toilet in a Star Hotel or Business with built up area more than 20,000 m2
  3. Each conference and meeting room in a Star Hotel or Business
  4. Each room of size more than 30 m2 in Educational buildings

5.2.3.4 Fan Controls

Cooling towers in buildings with built up area greater than 20,000 m2, shall have fan controls based on wet bulb logic, with either:

  1. Two speed motors, pony motors, or variable speed drives controlling the fans, or
  2. Controls capable of reducing the fan speed to at least two third of installed fan power

5.2.3.5 Dampers

All air supply and exhaust equipment, having a Variable Frequency Drive (VFD), shall have dampers that automatically close upon:

  1. Fan shutdown, or,
  2. When spaces served are not in use
  3. Backdraft gravity damper is acceptable in the system with design outdoor air of the system is less than 150 liters per second in all climatic zones except cold climate, provided backdraft dampers for ventilation air intakes are protected from direct exposure to wind.
  4. Dampers are not required in ventilation or exhaust systems serving naturally conditioned spaces.
  5. Dampers are not required in exhaust systems serving kitchen exhaust hoods.

5.2.4 Piping and Ductwork*

5.2.4.1 Piping Insulation

Piping for heating, space conditioning, and service hot water systems shall meet the insulation requirements listed in Table 5-7 through Table 5-9. Insulation exposed to weather shall be protected by aluminum sheet metal, painted canvas, or plastic cover. Cellular foam insulation shall be protected as above, or be painted with water retardant paint.

Exceptions to §5.2.4.1:

  1. Reduction in insulation R value by 0.2 (compared to values in Table 5-7, Table 5-8 and Table 5-9) to a minimum insulation level of R-0.4 shall be permitted for any pipe located in partition within a conditioned space or buried.
  2. Insulation R value shall be increased by 0.2 over and above the requirement stated in Table 5-7 through Table 5-9 for any pipe located in a partition outside a building with direct exposure to weather.
Table 5-7 Insulation Requirements for Pipes in ECBC Building
Operating Temperature (ºC) Pipe size (mm)
<40 ≥40
Insulation R value (m2.K/W)
Heating System
> 94°C & <= 121°C 0.9 1.2
> 60°C & <= 94°C 0.7 0.7
> 40°C & <= 60°C 0.4 0.7
Cooling System
> 4.5°C & <= 15°C 0.4 0.7
< 4.5°C 0.9 1.2
Refrigerant Piping (Split systems)
> 4.5°C & <= 15°C 0.4 0.7
< 4.5°C 0.9 1.2
Table 5-8 Insulation Requirements for Pipes in ECBC+ Building
Operating Temperature (ºC) Pipe size (mm)
<40 ≥40
Insulation R value (m2.K/W)
Heating System
> 94°C & <= 121°C 1.1 1.3
> 60°C & <= 94°C 0.8 0.8
> 40°C & <= 60°C 0.5 0.9
Cooling System
> 4.5°C & <= 15°C 0.5 0.9
< 4.5°C 1.1 1.3
Refrigerant Piping (Split systems)
> 4.5°C & <= 15°C 0.5 0.9
< 4.5°C 1.1 1.3
Table 5-9 Insulation Requirements for Pipes in SuperECBC Building
Operating Temperature (ºC) Pipe size (mm)
<25 ≥40
Insulation R value (m2.K/W)
Heating System
> 94°C & <= 121°C 1.5 1.5
> 60°C & <= 94°C 1.0 1.3
> 40°C & <= 60°C 0.7 1.1
Cooling System
> 4.5°C & <= 15°C 0.7 1.2
< 4.5°C 1.5 1.5
Refrigerant Piping (Split systems)
> 4.5°C & <= 15°C 0.4 0.7
< 4.5°C 1.5 1.5

5.2.4.2 Ductwork and Plenum Insulation

Ductwork and plenum shall be insulated in accordance with Table 5-10.

Table 5-10 Ductwork Insulation (R value in m2.K/W) Requirements
Duct Location Supply ducts Return ducts
Exterior R -1.4 R -0.6
Unconditioned Space R -0.6 None
Buried R -0.6 None

5.2.5 System Balancing*

5.2.5.1 General

System balancing shall be done for systems serving zones with a total conditioned area exceeding 500 m2.

5.2.5.2 Air System Balancing

Air systems shall be balanced in a manner to first minimize throttling losses; then, for fans with fan system power greater than 0.75 kW, fan speed shall be adjusted to meet design flow conditions.

5.2.5.3 Hydronic System Balancing

Hydronic systems shall be proportionately balanced in a manner to first minimize throttling losses; then the pump impeller shall be trimmed or pump speed shall be adjusted to meet design flow conditions.

5.2.6 Condensers*

5.2.6.1 Condenser Locations

Condensers shall be located such that the heat sink is free of interference from heat discharge by devices located in adjoining spaces, and do not interfere with other such systems installed nearby.

5.2.7 Service Water Heating*

5.2.7.1 Solar Water Heating

Hospitality and Healthcare in all climatic zones and all buildings in cold climate zone with a hot water system, shall have solar water heating equipment installed to provide for::

  1. at least 20% of the total hot water design capacity if above grade floor area of the building is less than 20,000 m2
  2. at least 40% of the total hot water design capacity if above grade floor area of the building is greater than or equal to 20,000 m2

Exception to §5.2.7.1: Systems that use heat recovery to provide the hot water capacity required as per the building type and size.

5.2.7.2 Heating Equipment Efficiency

Service water heating equipment shall meet or exceed the performance and minimum efficiency requirements presented in available Indian Standards

  1. Solar water heater shall meet the performance/ minimum efficiency level mentioned in IS 13129 Part (1&2)
  2. Gas Instantaneous water heaters shall meet the performance/minimum efficiency level mentioned in IS 15558 with above 80% Fuel utilization efficiency.
  3. Electric water heater shall meet the performance/ minimum efficiency level mentioned in IS 2082.
  4. For evacuated tube collector the storage tanks shall meet the IS 16542:2016, tubes shall meet IS 16543:2016 and IS 16544:2016 for the complete system.

5.2.7.3 Other Water Heating System

Supplementary heating system shall be designed to maximize the energy efficiency of the system and shall incorporate the following design features in cascade:

  1. Maximum heat recovery from hot discharge system like condensers of air conditioning units,
  2. Use of gas fired heaters wherever gas is available, and
  3. Electric heater as last resort.

5.2.7.4 Piping Insulation

Piping insulation shall comply with §5.2.4.1. The entire hot water system including the storage tanks, pipelines shall be insulated conforming to the relevant IS standards on materials and applications.

5.2.7.5 Heat Traps

Vertical pipe risers serving storage water heaters and storage tanks not having integral heat traps and serving a non-recirculating system shall have heat traps on both the inlet and outlet piping.

5.2.7.6 Swimming Pools

All heated pools shall be provided with a vapor retardant pool cover on or at the water surface. Pools heated to more than 32°C shall have a pool cover with a minimum insulation value of R-4.1.

5.3 Prescriptive Requirements

Compliance shall be demonstrated with the prescriptive requirements in this section. Supply, exhaust, and return or relief fans with motor power exceeding 0.37 kW shall meet or exceed the minimum energy efficiency requirements specified in Table 5-11 through Table 5-13 except the following need not comply with the requirement

  1. Fans in un-ducted air conditioning unit where fan efficiency has already been taken in account to calculate the efficiency standard of the comfort system.
  2. Fans in Health Care buildings having HEPA filters.
  3. Fans inbuilt in energy recovery systems that pre-conditions the outdoor air.
Table 5-11 Mechanical and Motor Efficiency Requirements for Fans in ECBC Buildings
System type Fan Type Mechanical Efficiency Motor Efficiency (As per IS 12615)
Air-handling unit Supply, return and exhaust 60% IE 2
Table 5-12 Mechanical and Motor Efficiency Requirements for Fans in ECBC+ Buildings
System type Fan Type Mechanical Efficiency Motor Efficiency (As per IS 12615)
Air-handling unit Supply, return and exhaust 65% IE 3
Table 5-13 Mechanical and Motor Efficiency Requirements for Fans in SuperECBC Buildings
System type Fan Type Mechanical Efficiency Motor Efficiency (As per IS 12615)
Air-handling unit Supply, return and exhaust 70% IE 4

5.3.1 Chillers

Chillers shall meet or exceed the minimum efficiency requirements for ECBC+ and SuperECBC Buildings are presented in Table 5-14 through Table 5-16 under ANSI/ AHRI 550/ 590 conditions.

Table 5-14 Minimum Energy Efficiency Requirements for water cooled Chillers
ECBC+ Building SuperECBC Building
Chiller Capacity (kWr) COP IPLV COP IPLV
< 260 5.2 6.9 5.8 7.1
≥ 260 & < 530 5.8 7.1 6.0 7.9
≥ 530 & < 1,050 5.8 7.5 6.3 8.4
≥ 1,050 && < 1,580 6.2 8.1 6.5 8.8
≥ 1,580 6.5 8.9 6.7 9.1
Table 5-15 Minimum Energy Efficiency Requirements for air cooled Chillers
ECBC+ Building SuperECBC Building
Chiller Capacity (kWr) COP IPLV COP/IPLV
< 260 3.0 4.0 NA
≥ 260 3.2 5.0 NA

5.3.2 Pumps

Chilled and condenser water pumps shall meet or exceed the minimum energy efficiency requirements specified in Table 5-16 through Table 5-18. Requirements for pumps in district chiller systems and hot water pumps for space heating are limited to the installed efficiency requirement of individual pump equipment only. To show compliance, calculate the total installed pump capacity in kilo watt and achieve the prescribed limits per kilo watt of refrigeration installed in the building.

Exceptions to §5.3.2: Pumps used in processes e.g. service hot water, chilled water used for refrigeration etc.

Table 5-16 Pump Efficiency Requirements for ECBC Building
Equipment ECBC
Chilled Water Pump (Primary and Secondary) 18.2 W/kWr with VFD on secondary pump
Condenser Water Pump 17.7 W/kWr
Pump Efficiency (minimum) 70%
Table 5-17 Pump Efficiency Requirements for ECBC+ Building
Equipment ECBC+
Chilled Water Pump (Primary and Secondary) 16.9 W/kWr with VFD on secondary pump
Condenser Water Pump 16.5 W/kWr
Pump Efficiency (minimum) 75%
Table 5-18 Pump Efficiency Requirements for SuperECBC Building
Equipment SuperECBC
Chilled Water Pump (Primary and Secondary) 14.9 W/kWr with VFD on secondary pump
Condenser Water Pump 14.6 W/kWr
Pump Efficiency (minimum) 85%

5.3.3 Cooling Towers

Cooling towers shall meet or exceed the minimum efficiency requirements specified in Table 5-19. ECBC+ and SuperECBC Buildings shall have additional VFD installed in the cooling towers.

Table 5-19 Cooling Tower Efficiency Requirements for ECBC, ECBC+, and SuperECBC Buildings
Equipment type Rating Condition Efficiency
Open circuit cooling tower Fans 35°C entering water
29°C leaving water
24°C WB outdoor air
0.017 kW/kWr
0.31 kW/L/s

5.3.4 Boilers

Gas and oil fired boilers shall meet or exceed the minimum efficiency requirements specified in Table 5-20.

Table 5-20 Minimum Efficiency Requirements for Oil and Gas Fired Boilers for ECBC+ and SuperECBC building
Equipment Type Sub Category Size Category Minimum FUE
Boilers, Hot Water Gas or oil fired All capacity 85%
FUE - fuel utilization efficiency

5.3.5 Economizers

5.3.5.1 Economizer for ECBC, ECBC+, and SuperECBC Building

Each cooling fan system in buildings with built up area greater than 20,000 m2, shall include at least one of the following:

  1. An air economizer capable of modulating outside-air and return-air dampers to supply 50% of the design supply air quantity as outside-air.
  2. A water economizer capable of providing 50% of the expected system cooling load at outside air temperatures of 10°C dry-bulb/7.2°C wet-bulb and below.

Exception to §5.3.5.1:

  1. Projects in warm-humid climate zones.
  2. Projects with only daytime occupancy in the hot-dry.
  3. Individual cooling or heating fan systems less than 3,200 liters per second.

5.3.5.2 Partial Cooling

Where required by §5.3.5.1 economizers shall be capable of providing partial cooling even when additional mechanical cooling is required to meet the cooling load.

5.3.5.3 Economizer Controls

Air economizer shall be equipped with controls

  1. That allow dampers to be sequenced with the mechanical cooling equipment and not be controlled by only mixed air temperature.
  2. capable of automatically reducing outdoor air intake to the design minimum outdoor air quantity when outdoor air intake will no longer reduce cooling energy usage.
  3. Capable of high-limit shutoff at 24 °C dry bulb temperature.

5.3.5.4 Testing

Air-side economizers shall be tested in the field following the requirements in §12 Appendix C to ensure proper operation.

Exception to §5.3.5.4: Air economizers installed by the HVAC system equipment manufacturer and certified to the building department as being factory calibrated and tested per the procedures in §12.

5.3.6 Variable Flow Hydronic Systems

5.3.6.1 Variable Fluid Flow

HVAC pumping systems having a total pump system power exceeding 7.5 kW shall be designed for variable fluid flow and shall be capable of reducing pump flow rates to an extent which is lesser or equal to the limit, where the limit is set by the larger of:

  1. 50% of the design flow rate, or
  2. the minimum flow required by the equipment manufacturer for proper operation of the chillers or boilers.

5.3.6.2 Isolation Valves

Water cooled air-conditioning or heat pump units with a circulation pump motor greater than or equal to 3.7 kW shall have two-way automatic isolation valves on each water-cooled air-conditioning or heat pump unit that are interlocked with the compressor to shut off condenser water flow when the compressor is not operating.

5.3.6.3 Variable Speed Drives

Chilled water or condenser water systems that must comply with either §5.3.6.1 or §5.3.6.2 and that have pump motors greater than or equal to 3.7 kW shall be controlled by variable speed drives.

5.3.7 Unitary, Split, Packaged Air-Conditioners

Unitary air-conditioners shall meet or exceed the efficiency requirements given in Table 5-21 and Table 5-22. Window and split air conditioners shall be certified under BEE’s Star Labeling Program. EER shall be as per IS 8148 for all unitary, split, packaged air conditioners greater than 10 kWr.

Table 5-21 Minimum Requirements for Unitary, Split, Packaged Air Conditioners in ECBC+ Building
Cooling Capacity (kWr) Water Cooled Air Cooled
≤ 10.5 NA BEE 4 Star
> 10.5 3.7 EER 3.2 EER
Table 5-22 Minimum Requirements for Unitary, Split, Packaged Air Conditioners in SuperECBC Building
Cooling Capacity (kWr) Water Cooled Air Cooled
≤ 10.5 NA BEE 5 Star
> 10.5 3.9 EER 3.4 EER

5.3.8 Controls for ECBC+ and SuperECBC Buildings

ECBC+ building shall comply with requirements of §5.3.8 in addition to complying with requirements of §5.2.3.

5.3.8.1 Centralized Demand Shed Controls

ECBC+ and SuperECBC Buildings with built up area greater than 20,000 m2 shall have a building management system. All mechanical cooling and heating systems in ECBC+ and SuperECBC Buildings with any programmable logic controller (PLC) to the zone level shall have the following control capabilities to manage centralized demand shed in noncritical zones:

  1. Automatic demand shed controls that can implement a centralized demand shed in non-critical zones during the demand response period on a demand response signal.
  2. Controls that can remotely decrease or increase the operating temperature set points by four degrees or more in all noncritical zones on signal from a centralized control point
  3. Controls that can provide an adjustable rate of change for the temperature setup and reset

The centralized demand shed controls shall have additional capabilities to

  1. Be disabled by facility operators
  2. Be manually controlled from a central point by facility operators to manage heating and cooling set points

5.3.8.2 Supply Air Temperature Reset

Multi zone mechanical cooling and heating systems in ECBC+ and SuperECBC Buildings shall have controls that automatically reset the supply-air temperature in response to building loads or to outdoor air temperature. Controls shall reset the supply air temperature to at least 25% of the difference between the design supply air temperature and the design room air temperature.

Exception to §5.3.8.2: ECBC+ and SuperECBC Buildings in warm humid climate zone.

5.3.8.3 Chilled Water Temperature Reset

Chilled water systems with a design capacity exceeding 350 kWr supplying chilled water to comfort conditioning systems in ECBC+ and SuperECBC Buildings shall have controls that automatically reset supply water temperatures by representative building loads (including return water temperature) or by outdoor air temperature.

Exceptions to §5.2.8.3: Controls to automatically reset chilled water temperature shall not be required where the supply temperature reset controls causes improper operation of equipment.

5.3.9 Controls for SuperECBC Buildings

SuperECBC Buildings shall comply with requirements of §5.3.9 in addition to complying with requirements of §5.2.3 and §5.3.8.

5.3.9.1 Variable Air Volume Fan Control

Fans in Variable Air Volume (VAV) systems in SuperECBC Buildings shall have controls or devices that will result in fan motor demand of no more than 30% of their design wattage at 50% of design airflow based on manufacturer’s certified fan data.

5.3.10 Energy Recovery

All Hospitality and Healthcare, with systems of capacity greater than 2,100 liters per second and minimum outdoor air supply of 70% shall have air-to-air heat recovery equipment with minimum 50% recovery effectiveness

At least 50% of heat shall be recovered from diesel and gas fired generator sets installed in Hospitality, Healthcare, and Business buildings with built up area greater than 20,000 m2.

5.3.11 Service Water Heating

For compliance with ECBC+ and SuperECBC,

  1. Hospitality and Healthcare in all climatic zones shall have solar water heating equipment installed to provide at least 40% of the total hot water design capacity.
  2. All buildings in cold climate zone with a hot water system, shall have solar water heating equipment installed to provide at least 60% of the total hot water design capacity.

Exception to §5.3.11: Systems that use heat recovery to provide the hot water capacity required as per the building type, size and efficiency level.

5.3.12 Total System Efficiency – Alternate Compliance Approach

Buildings may show compliance by optimizing the total system efficiency for the plant side comfort system instead of the individual equipment mentioned under the prescriptive requirement. This alternate compliance approach is applicable for central chilled water plant side system in all building types. The total installed capacity per kilo-watt refrigeration load shall be less than or equal to maximum threshold requirements as specified in Table 5-23. Equipment that can be included in central chilled water plant side system for this alternate approach are chillers, chilled water pumps, condenser water pumps, and cooling tower fan. Compliance check will be based on annual hourly simulation refer Table 9-1 for developing the proposed design.

Table 5-23 Maximum System Efficiency Threshold for ECBC, ECBC+, and SuperECBC Buildings
Water Cooled Chilled Water Plant Maximum Threshold (kW/kWr)
ECBC 0.26
ECBC+ 0.23
SuperECBC 0.20

5.3.12.1 Documentation Requirement

Compliance shall be documented and compliance forms shall be submitted to the authority having jurisdiction. The information submitted shall include, at a minimum, the following:

  1. Summary describing the results of the analysis, including the annual energy use (kWh) of chilled water plant (chillers, pumps and cooling tower) and annual chilled water use (kWrh) for the Proposed Design, and software used.
  2. Brief description of the project with location, number of stories, space types, conditioned and unconditioned areas, hours of operation.
  3. List of the energy-related building features of the Proposed Design.
  4. List showing compliance with the mandatory requirements of this code.
  5. The input and output report(s) from the simulation program including an energy and chilled water usage components: space cooling and heat rejection equipment, and other HVAC equipment (such as pumps). The output reports shall also show the number of hours any loads are not met by the HVAC system the Proposed Design.
  6. Explanation of any significant modelling assumptions made.
  7. Explanation of any error messages noted in the simulation program output.

The total system efficiency shall be calculated as follows:

Total System Efficiency= (Chilled water plant use (kWh))/(Chilled water use (kWrh))

5.3.13 Low-energy Comfort Systems

Alternative HVAC systems which have low energy use may be installed in place of (or in conjunction with) refrigerant-based cooling systems. Such systems shall be deemed to meet the minimum space conditioning equipment efficiency levels of §5.2.2, but shall comply with all other applicable mandatory provisions of §5.2 as applicable. Wherever applicable, requirements of §5.3 and §5.3.12 will be complied with. The approved list of low energy comfort systems is given below:

  1. Evaporative cooling
  2. Desiccant cooling system
  3. Solar air conditioning
  4. Tri-generation (waste-to-heat)
  5. Radiant cooling system
  6. Ground source heat pump
  7. Adiabatic cooling system

Buildings with an approved low-energy comfort system installed for more than 50% of the sum of cooling and heating capacity requirement of the building shall be deemed equivalent to the ECBC+ building standard prescribed in §5.2.2.

Buildings having an approved low energy comfort system installed for more than 90% of the sum of cooling and heating capacity requirement of the building shall be deemed equivalent to the SuperECBC building standard prescribed in §5.2.2.

5.3.13.1 Documentation Requirement

Compliance shall be documented and submitted to the authority having jurisdiction. The information submitted shall include, at a minimum, the following:

  1. Summary describing the low-energy comfort system type, capacity, and efficiency
  2. List of showing compliance with the mandatory and prescriptive requirements other than exempted in §5.3.13.
  3. Comparison of installed capacity of approved low-energy comfort system with other HVAC system to meet the comfort requirement of the building.

Lighting and Controls

6.2.1 Lighting Control

6.2.1.1 Automatic Lighting Shutoff

  1. 90% of interior lighting fittings in building or space of building larger than 300 m2 shall be equipped with automatic control device.
  2. Automatic control device shall function on either:
    1. A scheduled basis at specific programmed times. An independent program schedule shall be provided for areas of no more than 2,500 m2 and not more than one floor, or,
    2. Occupancy sensors that shall turn off the lighting fixtures within 15 minutes of an occupant leaving the space. Light fixtures controlled by occupancy sensors shall have a wall-mounted, manual switch capable of turning off lights when the space is occupied.
  3. Additionally, occupancy sensors shall be provided in
    1. All building types greater than 20,000 m2 BUA, in
      1. All habitable spaces less than 30 m2, enclosed by walls or ceiling height partitions.
      2. All storage or utility spaces more than 15 m2.
      3. Public toilets more than 25 m2, controlling at least 80% of lighting by wattage, fitted in the toilet. The lighting fixtures, not controlled by automatic lighting shutoff, shall be uniformly spread in the area.
    2. Corridors of all Hospitality greater than 20,000 m2 BUA, controlling minimum 70% and maximum 80% of lighting by wattage, fitted in the public corridor. The lighting fixtures, not controlled by automatic lighting shut off, shall be uniformly spread in the area.
    3. All conference or meeting rooms.

Exception to §6.2.1.1: Lighting systems designed for emergency and firefighting purposes.

6.2.1.2 Space Control

Each space enclosed by ceiling-height partitions shall have at least one control device to independently control the general lighting within the space. Each control device shall be activated either manually by an occupant or automatically by sensing an occupant. Each control device shall

  1. control a maximum of 250 m2 for a space less than or equal to 1,000 m2, and a maximum of 1,000 m2 for a space greater than 1,000 m2.
  2. have the capability to override the shutoff control required in §6.2.1.1 for no more than 2 hours, and
  3. be readily accessible and located so the occupants can see the control.

Exception to §6.2.1.2 (c): The required control device may be remotely installed if required for reasons of safety or security. A remotely located device shall have a pilot light indicator as part of or next to the control device and shall be clearly labeled to identify the controlled lighting.

6.2.1.3 Control in Daylight Areas

  1. Luminaires, installed within day lighting extent from the window as calculated in §4.2.3, shall be equipped with either a manual control device to shut off luminaires, installed within day lit area, during potential daylit time of a day or automatic control device that:
    1. Has a delay of minimum 5 minutes, or,
    2. Can dim or step down to 50% of total power.
  2. Overrides to the daylight controls shall not be allowed.

6.2.1.4 Exterior Lighting Control

  1. Lighting for all exterior applications shall be controlled by a photo sensor or astronomical time switch that is capable of automatically turning off the exterior lighting when daylight is available or the lighting is not required.
  2. Lighting for all exterior applications, shall have lamp efficacy not less than 80 lumens per watt for ECBC, unless the luminaire is controlled by a motion sensor or exempt under §6.1.
  3. Façade lighting and façade non-emergency signage of Shopping Complexes shall have separate time switches.

Exemption to §6.2.1.4: Exterior Lighting systems designed for emergency and firefighting purposes.

6.2.1.5 Additional Control

The following lighting applications shall be equipped with a control device to control such lighting independently of general lighting:

  1. Display/ Accent Lighting. Display or accent lighting greater than 300 m2 area shall have a separate control device.
  2. Hotel Guest Room Lighting. Guest rooms and guest suites in a hotel shall have a master control device at the main room entry that controls all permanently installed luminaires and switched receptacles.
  3. Task Lighting. Supplemental task lighting including permanently installed under shelf or under cabinet lighting shall have a control device integral to the luminaires or be controlled by a wall-mounted control device provided the con-trol device complies with §6.2.1.2.
  4. Nonvisual Lighting. Lighting for nonvisual applications, such as plant growth and food-warming, shall be equipped with a separate control device.
  5. Demonstration Lighting. Lighting equipment that is for sale or for demonstrations in lighting education shall be equipped with a separate control device accessible only to authorized personnel.

6.2.2 Exit Signs*

Internally-illuminated exit signs shall not exceed 5 Watts per face.

6.3.1 Interior Lighting Power

The installed interior lighting power for a building or a separately metered or permitted portion of a building shall be calculated in accordance with §6.3.4 and shall not exceed the interior lighting power allowance determined in accordance with either §6.3.2 or §6.3.3.

Exception to §6.3.1: The following lighting equipment and applications shall not be considered when determining the interior lighting power allowance, nor shall the wattage for such lighting be included in the installed interior lighting power. However, any such lighting shall not be exempt unless it is an addition to general lighting and is controlled by an independent control device.

  1. Display or accent lighting that is an essential element for the function performed in galleries, museums, and monuments,
  2. Lighting that is integral to equipment or instrumentation and is installed by its manufacturer,
  3. Lighting specifically designed for medical or dental procedures and lighting integral to medical equipment,
  4. Lighting integral to food warming and food preparation equipment,
  5. Lighting for plant growth or maintenance,
  6. Lighting in spaces specifically designed for use by the visually impaired,
  7. Lighting in retail display windows, provided the display area is enclosed by ceiling-height partitions,
  8. Lighting in interior spaces that have been specifically designated as a registered interior historic landmark,
  9. Lighting that is an integral part of advertising or directional signage,
  10. Exit signs,
  11. Lighting that is for sale or lighting educational demonstration systems,
  12. Lighting for theatrical purposes, including performance, stage, and film or video production, and
  13. Athletic playing areas with permanent facilities for television broadcasting

6.3.2 Building Area Method

Determination of interior lighting power allowance (watts) by the building area method shall be in accordance with the following:

Determine the allowed lighting power density for each appropriate building area type from Table 6-1 for ECBC Buildings, from Table 6-2 for ECBC+ Buildings and from Table 6-3 for SuperECBC Buildings.

  1. Calculate the gross lighted carpet area for each building area type.
  2. The interior lighting power allowance is the sum of the products of the gross lighted floor area of each building area times the allowed lighting power density for that building area type.
Table 6-1 Interior Lighting Power for ECBC Buildings – Building Area Method
Building Area Type LPD(W/m2)
Office Building 9.5
Hospitals 9.7
Hotels 9.5
Shopping Mall 14.1
University and Schools 11.2
Library 12.2
Dining: bar lounge/leisure 12.2
Dining: cafeteria/fast food 11.5
Dining: family 10.9
Dormitory 9.1
Fire station 9.7
Gymnasium 10.0
Manufacturing facility 12.0
Motion picture theater 9.43
Museum 10.2
Post office 10.5
Religious building 12.0
Sports arena 9.7
Transportation 9.2
Warehouse 7.08
Performing arts theater 16.3
Police station 9.9
Workshop 14.1
Automotive facility 9.0
Convention center 12.5
Parking garage 3.0
In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply.
Table 6-2 Interior Lighting Power for ECBC+ Buildings – Building Area Method
Building Area Type LPD(W/m2)
Office Building 7.6
Hospitals 7.8
Hotels 7.6
Shopping Mall 11.3
University and Schools 9.0
Library 9.8
Dining: bar lounge/leisure 9.8
Dining: cafeteria/fast food 9.2
Dining: family 8.7
Dormitory 7.3
Fire station 7.8
Gymnasium 8.0
Manufacturing facility 9.6
Motion picture theater 7.5
Museum 8.2
Post office 8.4
Religious building 9.6
Sports arena 7.8
Transportation 7.4
Warehouse 5.7
Performing arts theater 13.0
Police station 7.9
Workshop 11.3
Automotive facility 7.2
Convention center 10.0
Parking garage 2.4
In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply.
Table 6-3 Interior Lighting Power for SuperECBC Buildings – Building Area Method
Building Area Type LPD(W/m2)
Office Building 5.0
Hospitals 4.9
Hotels 4.8
Shopping Mall 7.0
University and Schools 6.0
Library 6.1
Dining: bar lounge/leisure 6.1
Dining: cafeteria/fast food 5.8
Dining: family 5.5
Dormitory 4.6
Fire station 4.9
Gymnasium 5.0
Manufacturing facility 6.0
Motion picture theater 4.7
Museum 5.1
Post office 5.3
Religious building 6.0
Sports arena 4.9
Transportation 4.6
Warehouse 3.5
Performing arts theater 8.2
Police station 5.0
Workshop 7.1
Automotive facility 4.5
Convention center 6.3
Parking garage 1.5
In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply.

6.3.3 Space Function Method

Determination of interior lighting power allowance (watts) by the space function method shall be in accordance with the following:

  1. Determine the appropriate building type and the allowed lighting power density from Table 6-4 for ECBC Buildings, Table 6-5 for ECBC+ Buildings and, Table 6-6 for SuperECBC Buildings. In cases where both a common space type and building specific space type are listed, building specific space type LPD shall apply.
  2. For each space, enclosed by partitions 80% or greater than ceiling height, determine the gross lighted floor area by measuring to the center of the partition wall. Include the area of balconies or other projections. Retail spaces do not have to comply with the 80% partition height requirements.
  3. The interior lighting power allowance is the sum of the lighting power allowances for all spaces. The lighting power allowance for a space is the product of the gross lighted floor area of the space times the allowed lighting power density for that space.
Table 6-4 Interior Lighting Power for ECBC Buildings – Space Function Method
Category LPD (W/m2)
Common Space Types
Restroom 7.7
Storage 6.8
Conference/ Meeting 11.5
Parking Bays (covered/ basement) 2.2
Electrical/Mechanical 7.1
Stairway 5.5
Corridor/Transition 7.1
Lobby 9.1
Parking Driveways (covered/ basement) 3.0
Workshop 17.1
Business
Enclosed 10.0
Banking Activity Area 12.6
Open Plan 10.0
Service/Repair 6.8
Healthcare
Emergency 22.8
Exam/Treatment 13.7
Nurses’ Station 9.4
Operating Room 21.8
Patient Room 7.7
Pharmacy 10.7
Physical Therapy 9.7
Radiology/Imaging 9.1
Recovery 8.6
Storage 5.5
Laundry/Washing 7.5
Lounge/Recreation 8.0
Medical Supply 13.7
Nursery 5.7
Corridor/Transition 9.1
Hospitality
Hotel Dining 9.1
For Bar Lounge/ Dining 14.1
For food preparation 12.1
Hotel Guest Rooms 9.1
Hotel Lobby 10.9
Motel Dining 9.1
Motel Guest Rooms 7.7
Shopping Complex
Mall Concourse 12.8
Sales Area 18.3
Motion Picture Theatre 9.6
For Family Dining 10.9
For food preparation 12.1
Bar Lounge/ Dining 14.1
Educational
Classroom/Lecture 13.7
For Classrooms 13.8
Laboratory 15.1
Card File and Cataloguing 9.1
Stacks (Lib) 18.3
Reading Area (Library) 10.0
Assembly
Dressing Room 9.1
Exhibit Space - Convention Centre 14.0
Seating Area - Gymnasium 4.6
Fitness Area - Gymnasium 13.7
Museum - General Exhibition 16.4
Museum - Restoration 18.3
Seating Area - Performing Arts Theatre 22.6
Lobby - Performing Arts Theatre 21.5
Seating Area - Convention Centre 6.4
Seating Religious Building 16.4
Playing Area - Gymnasium 18.8
Table 6-5 Interior Lighting Power for ECBC+ Buildings – Space Function Method
Category LPD (W/m2)
Common Space Types
Restroom 6.1
Storage 5.4
Conference/ Meeting 9.2
Parking Bays (covered/ basement) 1.8
Electrical/Mechanical 5.7
Stairway 4.4
Corridor/Transition 3.6
Lobby 7.3
Parking Driveways (covered/ basement) 2.5
Workshop 13.7
Business
Enclosed 8.6
Banking Activity Area 9.3
Open Plan 8.6
Service/Repair 5.5
Healthcare
Emergency 18.2
Exam/Treatment 10.9
Nurses’ Station 7.5
Operating Room 17.5
Patient Room 6.1
Pharmacy 8.5
Physical Therapy 7.8
Radiology/Imaging 7.3
Recovery 7.0
Storage 4.4
Laundry/Washing 6.0
Lounge/Recreation 6.4
Medical Supply 10.9
Nursery 4.6
Corridor/Transition 7.3
Hospitality
Hotel Dining 7.3
For Bar Lounge/ Dining 11.3
For food preparation 12.1
Hotel Guest Rooms 7.3
Hotel Lobby 8.8
Motel Dining 7.3
Motel Guest Rooms 6.1
Shopping Complex
Mall Concourse 10.2
Sales Area 14.6
Motion Picture Theatre 10.3
For Family Dining 8.8
For food preparation 12.1
Bar Lounge/ Dining 11.3
Educational
Classroom/Lecture 10.9
For Classrooms 11.0
Laboratory 12.1
Card File and Cataloguing 7.3
Stacks (Lib) 14.6
Reading Area (Library) 9.2
Assembly
Dressing Room 7.3
Exhibit Space - Convention Centre 11.2
Seating Area - Gymnasium 3.6
Fitness Area - Gymnasium 7.9
Museum - General Exhibition 11.3
Museum - Restoration 11.0
Seating Area - Performing Arts Theatre 18.1
Lobby - Performing Arts Theatre 17.2
Seating Area - Convention Centre 5.1
Seating Religious Building 13.1
Playing Area - Gymnasium 12.9
Table 6-6 Interior Lighting Power for SuperECBC Buildings – Space Function Method
Category LPD (W/m2)
Common Space Types
Restroom 3.8
Storage 3.4
Conference/ Meeting 5.7
Parking Bays (covered/ basement) 1.1
Electrical/Mechanical 3.5
Stairway 2.7
Corridor/Transition 2.3
Lobby 4.6
Parking Driveways (covered/ basement) 1.5
Workshop 8.6
Business
Enclosed 5.4
Banking Activity Area 5.8
Open Plan 5.4
Service/Repair 3.4
Healthcare
Emergency 11.4
Exam/Treatment 6.8
Nurses’ Station 5.0
Operating Room 10.9
Patient Room 3.8
Pharmacy 5.3
Physical Therapy 4.9
Radiology/Imaging 4.6
Recovery 4.4
Storage 2.7
Laundry/Washing 3.8
Lounge/Recreation 4.6
Medical Supply 6.8
Nursery 2.9
Corridor/Transition 4.6
Hospitality
Hotel Dining 4.6
For Bar Lounge/ Dining 7.0
For food preparation 7.5
Hotel Guest Rooms 4.6
Hotel Lobby 5.5
Motel Dining 4.6
Motel Guest Rooms 3.8
Shopping Complex
Mall Concourse 6.40
Sales Area 9.2
Motion Picture Theatre 6.5
For Family Dining 5.5
For food preparation 7.5
Bar Lounge/ Dining 7.0
Educational
Classroom/Lecture 6.8
For Classrooms 6.9
Laboratory 7.5
Card File and Cataloguing 4.6
Stacks (Lib) 9.2
Reading Area (Library) 5.7
Assembly
Dressing Room 4.6
Exhibit Space - Convention Centre 7.0
Seating Area - Gymnasium 3.4
Fitness Area - Gymnasium 3.9
Museum - General Exhibition 5.7
Museum - Restoration 5.5
Seating Area - Performing Arts Theatre 11.3
Lobby - Performing Arts Theatre 10.8
Seating Area - Convention Centre 3.2
Seating Religious Building 8.2
Playing Area - Gymnasium 6.5

6.3.4 Installed Interior Lighting Power

The installed interior lighting power calculated for compliance with §6.3 shall include all power used by the luminaires, including lamps, ballasts, current regulators, and control devices except as specifically exempted in §6.1.

Exception to §6.3.4: If two or more independently operating lighting systems in a space are controlled to prevent simultaneous user operation, the installed interior lighting power shall be based solely on the lighting system with the highest power.

6.3.4.1 Luminaire Wattage

Light output ratio shall be 0.7 or above. Luminaire wattage incorporated into the installed interior lighting power shall be determined in accordance with the following:

  1. The wattage of incandescent luminaires with medium base sockets and not containing permanently installed ballasts shall be the maximum labeled wattage of the luminaires.
  2. The wattage of luminaires containing permanently installed ballasts shall be the operating input wattage of the specified lamp/ballast combination. Operating input wattage can be either values from manufacturers’ catalogs or values from independent testing laboratory reports.
  3. The wattage of all other miscellaneous luminaire types not described in (a) or (b) shall be the specified wattage of the luminaires.
  4. The wattage of lighting track, plug-in busway, and flexible-lighting systems that allow the addition and/ or relocation of luminaires without altering the wiring of the system shall be the larger of the specified wattage of the luminaires included in the system or 135 Watt per meter. Systems with integral overload protection, such as fuses or circuit breakers, shall be rated at 100% of the maximum rated load of the limiting device.

6.3.5 Exterior Lighting Power

Connected lighting power of exterior lighting applications shall not exceed the lighting power limits specified in Table 6-7 for ECBC Buildings, Table 6-8 for ECBC+ Buildings and Table 6-9 for SuperECBC Buildings. Trade-offs between applications are not permitted.

Table 6-7 Exterior Building Lighting Power for ECBC Buildings
Exterior lighting application Power limits
Building entrance (with canopy) 10 W/m2 of canopied
Building entrance (w/o canopy) 90 W/ linear m of door width
Building exit 60 W/lin m of door width
Building façade 5.0 W/m2 of vertical façade area
Emergency signs, ATM kiosks, Security areas façade 1.0 W/m2
Driveways and parking (open/ external) 1.6 W/m2
Pedestrian walkways 2.0 W/m2
Stairways 10.0 W/m2
Landscaping 0.5 W/m2
Outdoor sales area 9.0 W/m2
Table 6-8 Exterior Building Lighting Power for ECBC+ Buildings
Exterior lighting application Power limits
Building entrance (with canopy) 8 W/m2 of canopied
Building entrance (w/o canopy) 72 W/ linear m of door width
Building exit 48 W/lin m of door width
Building façade 4.0 W/m2 of vertical façade area
Emergency signs, ATM kiosks, Security areas façade 0.8 W/m2
Driveways and parking (open/ external) 1.3 W/m2
Pedestrian walkways 1.6 W/m2
Stairways 8.0 W/m2
Landscaping 0.4 W/m2
Outdoor sales area 7.2 W/m2
Table 6-9 Exterior Building Lighting Power for SuperECBC Buildings
Exterior lighting application Power limits
Building entrance (with canopy) 5 W/m2 of canopied
Building entrance (w/o canopy) 45 W/ linear m of door width
Building exit 30 W/lin m of door width
Building façade 2.5 W/m2 of vertical façade area
Emergency signs, ATM kiosks, Security areas façade 0.5 W/m2
Driveways and parking (open/ external) 0.8 W/m2
Pedestrian walkways 1.0 W/m2
Stairways 5.0 W/m2
Landscaping 0.25 W/m2
Outdoor sales area 4.5 W/m2

6.3.6 Controls for ECBC+ and SuperECBC Buildings

ECBC+ and SuperECBC Buildings shall comply with requirements of §6.3.6 in addition to complying with requirements of §6.2.

6.3.6.1 Centralized Controls

ECBC+ and SuperECBC building shall have centralized control system for schedule based automatic lighting shutoff switches.

6.3.6.2 Exterior Lighting Controls

Lighting for all exterior applications, shall have lamp efficacy not less than 80 lumens per watt, 90 lumens per watt, and 100 lumens per watt, for ECBC, ECBC+, and SuperECBC Buildings respectively, unless the luminaire is controlled by a motion sensor.

Electrical and Renewable Energy Systems

7.2.1 Transformers*

7.2.1.1 Maximum Allowable Power Transformer Losses

Power transformers of the proper ratings and design must be selected to satisfy the minimum acceptable efficiency at 50% and full load rating. The permissible loss shall not exceed to values listed in Table 7-1 for dry type transformers and Table 7-2 for oil type transformers.

Table 7-1 Permissible Losses for Dry Type Transformers
Rating (kVA) Max. Losses at 50% loading (W)* Max. Losses at 100% loading (W)* Max. Losses at 50% loading (W)* Max. Losses at 100% loading (W)*
Up to 22 kV class 33 kV class
100 940 2400 1120 2400
160 1290 3300 1420 3300
200 1500 3800 1750 4000
250 1700 4320 1970 4600
315 2000 5040 2400 5400
400 2380 6040 2900 6800
500 2800 7250 3300 7800
630 3340 8820 3950 9200
800 3880 10240 4650 11400
1000 4500 12000 5300 12800
1250 5190 13870 6250 14500
1600 6320 16800 7500 18000
2000 7500 20000 8880 21400
2500 9250 24750 10750 26500
* The values as per Indian Standard/BEE Standard & Labeling notification for dry type transformer corresponding to values in this table will supersede as and when the Indian standards/ BEE Standard & Labeling notification are published.
Table 7-2 Permissible Losses for Oil Type Transformers
Rating (kVA) Impedance (%) Max. Total Loss (W) for transformers up to 11 kV class
ECBC Building
50 % Load 100% Load
16 4.5 150 480
25 4.5 210 695
63 4.5 380 1,250
100 4.5 520 1,800
160 4.5 770 2,200
200 4.5 890 2,700
250 4.5 1,050 3,150
315 4.5 1,100 3,275
400 4.5 1,300 3,875
500 4.5 1,600 4,750
630 4.5 2,000 5,855
1000 5 3,000 9,000
1250 5 3,600 10,750
1600 6.25 4,500 13,500
2000 6.25 5,400 17,000
2500 6.25 6,500 20,000
Rating (kVA) Impedance (%) Max. Total Loss (W) for transformers up to 11 kV class
ECBC+ Building
50 % Load 100% Load
16 4.5 135 440
25 4.5 190 635
63 4.5 340 1,140
100 4.5 475 1,650
160 4.5 670 1,950
200 4.5 780 2,300
250 4.5 980 2,930
315 4.5 1,025 3,100
400 4.5 1,225 3,450
500 4.5 1,510 4,300
630 4.5 1,860 5,300
1000 5 2,790 7,700
1250 5 3,300 9,200
1600 6.25 4,200 11,800
2000 6.25 5,050 15,000
2500 6.25 6,150 18,500
Rating (kVA) Impedance (%) Max. Total Loss (W) for transformers up to 11 kV class
SuperECBC Building
50 % Load 100% Load
16 4.5 120 400
25 4.5 175 595
63 4.5 300 1,050
100 4.5 435 1,500
160 4.5 570 1,700
200 4.5 670 2,100
250 4.5 920 2,700
315 4.5 955 2,750
400 4.5 1,150 3,330
500 4.5 1,430 4,100
630 4.5 1,745 4,850
1000 5 2,620 7,000
1250 5 3,220 8,400
1600 6.25 3,970 11,300
2000 6.25 4,790 14,100
2500 6.25 5,900 17,500
Total loss values given in above table are applicable for thermal classes E, B and F and have component of load loss at reference temperature according to Clause 17 of IS. An increase of 7% on total for thermal class H is allowed.

Permissible total loss values shall not exceed

  1. 5% of the maximum total loss values mentioned in IS 1180 for oil type transformers in voltage class above 11 kV but not more than 22 kV
  2. 7.5% of the maximum total loss values mentioned in above IS 1180 for oil type transformers in voltage class above 22 kV and up to and including 33 kV

7.2.1.2 Measurement and Reporting of Transformer Losses

All measurement of losses shall be carried out by using calibrated digital meters of class 0.5 or better accuracy and certified by the manufacturer. All transformers of capacity of 500 kVA and above would be equipped with additional metering class current transformers (CTs) and potential transformers (PTs) additional to requirements of Utilities so that periodic loss monitoring study may be carried out.

7.2.1.3 Voltage Drop

Voltage drop for feeders shall not exceed 2% at design load. Voltage drop for branch circuit shall not exceed 3% at design load.

7.2.2 Energy Efficient Motors*

Motors shall comply with the following:

  1. Three phase induction motors shall conform to Indian Standard (IS) 12615 and shall fulfil the following efficiency requirements:
    1. ECBC Buildings shall have motors of IE 2 (high efficiency) class or a higher class
    2. ECBC+ Buildings shall have IE 3 (premium efficiency) class motors or higher class
    3. SuperECBC Buildings shall have IE 4 (super premium efficiency) class motors
  2. Motors of horsepower differing from those listed in the table shall have efficiency greater than that of the next listed kW motor.
  3. Motor horsepower ratings shall not exceed 20% of the calculated maximum load being served.
  4. Motor nameplates shall list the nominal full-load motor efficiencies and the full-load power factor.

7.2.3 Diesel Generator (DG) Sets*

BEE star rated DG sets shall be used in all compliant buildings. DG sets in buildings greater than 20,000 m2 BUA shall have:

  1. minimum 3 stars rating in ECBC Buildings
  2. minimum 4 stars rating in ECBC+ Buildings
  3. 5 stars rating in SuperECBC Buildings

7.2.4 Check-Metering and Monitoring*

At Building mains, installed meters must be capable of monitoring Energy use (kWh), Energy Demand (kW) and total Power Factor on an hourly basis. For sub-meters installed at building services, the following metering requirements must be complied with:

  1. Services exceeding 1000 kVA shall have permanently installed electrical metering to record demand (kVA), energy (kWh), and total power factor on hourly basis. The metering shall also display current (in each phase and the neutral), voltage (between phases and between each phase and neutral), and total harmonic distortion (THD) as a percentage of total current.
  2. Services not exceeding 1000 kVA but over 65 kVA shall have permanently installed electric metering to record demand (kW), energy (kWh), and total power factor (or kVARh) on hourly basis.
  3. Services not exceeding 65 kVA shall have permanently installed electrical metering to record energy (kWh) on hourly basis.

Sub-metering requirements for different services are outlined in Table 7-3.

Table 7-3 Sub Metering: Minimum requirement for separation of electrical load
Building Contract Demand
120 kVA to 250 kVA Greater than 250 kVA
HVAC system and components Required Required
Interior and Exterior Lighting Not required Required
Domestic hot water Not required Required
Plug loads Not required Required
Renewable power source Required Required

In addition to requirements stated above, for building types identified in Table 7-4, respective services must be sub-metered.

Table 7-4 Additional sub-metering requirements for specific building types
Mandatory requirement of sub- metering of services for specific building types
Shopping Complex Façade lighting
Shopping Complex Elevator, escalators, moving walks
Business Data centers
Hospitality Commercial kitchens

For tenant based building, tenants must be provided with tap-off points to install electrical sub-meters.

7.2.5 Power Factor Correction*

All 3 phase shall maintain their power factor at the point of connection as follows:

  1. 0.97 for ECBC Building
  2. 0.98 for ECBC+ building
  3. 0.99 for SuperECBC building

7.2.6 Power Distribution Systems*

The power cabling shall be sized so that the distribution losses do not exceed

  1. 3% of the total power usage in ECBC Buildings
  2. 2% of the total power usage in ECBC+ Buildings
  3. 1% of total power usage in SuperECBC Buildings

Record of design calculation for the losses shall be maintained. Load calculation shall be calculated up to the panel level.

7.2.7 Uninterruptible Power Supply (UPS)*

In all buildings, UPS shall meet or exceed the energy efficiency requirements listed in Table 7-5. Any Standards and Labeling program by BEE shall take precedence over requirements listed in this section.

Table 7-5 Energy Efficiency Requirements for UPS for ECBC, ECBC+, SuperECBC building
UPS Size Energy Efficiency Requirements at 100% Load
kVA < 20 90.2%
20 ≤ kVA ≤ 100 91.9%
kVA > 100 93.8%

7.2.8 Renewable Energy Systems*

All buildings shall have provisions for installation of renewable energy systems in the future on rooftops or the site.

7.2.8.1 Renewable Energy Generating Zone (REGZ)

  1. A dedicated REGZ equivalent to at least 25% of roof area or area required for generation of energy equivalent to 1% of total peak demand or connected load of the building, whichever is less, shall be provided in all buildings.
  2. The REGZ shall be free of any obstructions within its boundaries and from shadows cast by objects adjacent to the zone
  3. ECBC+ and SuperECBC building shall fulfil the additional requirements listed in Table 7-6 and Table 7-7 respectively.
Table 7-5 Minimum Renewable Contribution towards meeting Contract Demand in ECBC+ Building
Building Type Minimum Capacity to be Installed in REGZ
All Building types except below Minimum 2% of total Contract Demand
Star Hotel > 20,000 m2 AGA
Resort > 12,500 m2 AGA
University > 20,000 m2 AGA
Business > 20,000 m2 AGA
Minimum 3% of total Contract Demand
Table 7-6 Minimum Renewable Contribution towards meeting Contract Demand in SuperECBC Building
Building Type Minimum Capacity to be Installed in REGZ
All Building types except below Minimum 4% of total Contract Demand /td>
Star Hotel > 20,000 m2 AGA
Resort > 12,500 m2
University > 20,000 m2 AGA
Business >20,000 m2 AGA
Minimum 6% of total Contract Demand

7.2.8.2 Main Electrical Service Panel

Minimum rating shall be displayed on the main electrical service panel. Space shall be reserved for the installation of a double pole circuit breaker for a future renewable electric installation.

7.2.8.3 Demarcation on Documents

The following shall be indicated in design and construction documents:

  1. Location for inverters and metering equipment,
  2. Pathway for routing of conduit from the REGZ to the point of interconnection with the electrical service,
  3. Routing of plumbing from the REGZ to the water-heating system and,
  4. Structural design loads for roof dead and live load.

Definition

  • A
  • Above grade area (AGA)
    AGA is the cumulative floor area of all the floor levels of a building that are above the ground level. Ground level shall be as defined in building site plan. A floor level is above grade if one-third of the total external surface area of only the said floor level is above the ground level.
    Accredited independent laboratory
    testing laboratory not affiliated with producer or consumer of goods or products tested at the laboratory and accredited by national or international organizations for technical competence
    Addition
    an extension or increase in floor area or height of a building outside of the existing building envelope.
    Air conditioning and condensing units serving computer rooms
    air conditioning equipment that provides cooling by maintaining space temperature and humidity within a narrow range. Major application is in data centers where dissipating heat generated by equipment takes precedence over comfort cooling for occupants.
    Alteration
    any change, rearrangement, replacement, or addition to a building or its systems and equipment; any modification in construction or building equipment.
    Area weighted average (AWA) method
    AWA method is based on the concept of weighted arithmetic mean where instead of each data point contributing equally to the final mean; each data point contributes more “weight” than others based on the size of the area the said data point is applicable to. To calculate the area weighted average mean, a summation of each data point multiplied with its respective area is divided with the total area. AWA=∑▒((Data point X area))/(Total area)
    Astronomical time switch
    an automatic time switch that makes an adjustment for the length of the day as it varies over the year.
    Authority having jurisdiction
    the agency or agent responsible for enforcing this code.
  • B
  • Balancing, air system
    adjusting airflow rates through air distribution system devices, such as fans and diffusers, by manually adjusting the position of dampers, splitters vanes, extractors, etc., or by using automatic control devices, such as constant air volume or variable air volume boxes.
    Balancing, hydronic system
    adjusting water flow rates through hydronic distribution system devices, such as pumps and coils, by manually adjusting the position valves, or by using automatic control devices, such as automatic flow control valves.
    Ballast
    a device used in conjunction with an electric-discharge lamp to cause the lamp to start and operate under proper circuit conditions of voltage, current, waveform, electrode heat, etc.
    Standard Design
    a computer model of a hypothetical building, based on actual building design, that fulfils all the mandatory requirements and minimally complies with the prescriptive requirements of ECBC.
    Boiler
    a self-contained low-pressure appliance for supplying steam or hot water
    Building or building complex or complex
    a structure wholly or partially enclosed within exterior walls, or within exterior and party walls, and a roof, affording shelter to persons, animals, or property. Building complex means a building or group of buildings constructed in a contiguous area for business, commercial, institutional, healthcare, hospitality purposes or assembly buildings under the single ownership of individuals or group of individuals or under the name of a co-operative group society or on lease and sold as shops or office space or space for other commercial purposes, having a connected load of 100 kW or contract demand of 120 kVA and above.
    Building, base
    includes building structure, building envelope, common areas, circulation areas, parking, basements, services area, plant room and its supporting areas and, open project site area.
    Building, core and shell
    buildings where the developer or owner will only provide the base building and its services.
    Building, existing
    a building or portion thereof that was previously occupied or approved for occupancy by the authority having jurisdiction.
    Building envelope
    the exterior plus the semi-exterior portions of a building. For the purposes of determining building envelope requirements, the classifications are defined as follows
    1. Building envelope, exterior: the elements of a building that separate conditioned spaces from the exterior
    2. (b) Building envelope, semi-exterior: the elements of a building that separate conditioned space from unconditioned space or that enclose semi-heated spaces through which thermal energy may be transferred to or from the exterior, or to or from unconditioned spaces, or to or from conditioned spaces
    Building grounds lighting
    lighting provided through a building’s electrical service for parking lot, site, roadway, pedestrian pathway, loading dock, and security applications
    Building material
    any element of the building envelope through which heat flows and that heat is included in the component U-factor calculations other than air films and insulation
    Built up area (BUA)
    sum of the covered areas of all floors of a building, other than the roof, and areas covered by external walls and parapet on these floors.
    24-hour Business Building
    Business building operated and occupied for more than 12 hours on each weekday. Intensity of occupancy may vary.
  • C
  • Cardinal direction
    cardinal directions or cardinal points are the four main directional points of a compass north, south, east, and west
    Centralized control
    single hardware/ software for observing and controlling operations of a group of equipment and devices with similar or different functions
    Circuit breaker
    a safety device that automatically stops flow of current in electrical circuits. It protects the circuit from current surge.
    Class of construction
    classification that determines the construction materials for the building envelope, roof, wall, floor, slab-on-grade floor, opaque door, vertical fenestration, skylight
    Daylight window
    fenestration 2.2 meter above floor level, with an interior light shelf at bottom of this fenestration
    Coefficient of Performance (COP) – cooling
    the ratio of the rate of heat removal to the rate of energy input, in consistent units, for a complete refrigerating system or some specific portion of that system under designated operating conditions
    Coefficient of Performance (COP) – heating
    the ratio of the rate of heat delivered to the rate of energy input, in consistent units, for a complete heat pump system, including the compressor and, if applicable, auxiliary heat, under designated operating conditions
    Common area
    areas within a building that are available for use by all tenants in a building (i.e. lobbies, corridors, restrooms, etc.)
    Commercial building
    a building or a part of building or building complex which are used or intended to be used for commercial purposes and classified as per the time of the day the building is operational and sub classified, as per the functional requirements of its design, construction, and use as per following details
    1. Group I – 24 hours building covering Type A Hospitality, Type B Health Care and Type C Assembly, Type D Business and
    2. Group II – Regular building covering Type D Business, Type E Educational and Type F Shopping Complexes.
    Compliance documents
    the forms specified in ECBC Rules and Regulations to record and check compliance with these rules. These include but are not limited to EPI Ratio Compliance Report, Building Envelope Compliance Form, Mechanical Systems Compliance Form and Permit Checklist, Lighting System Compliance Form and Permit Checklist and certificates from Certified Energy Auditor for existing or proposed buildings.
    Connected load
    the sum of the rated wattage of all equipment, appliances and devices to be installed in the building or part of building or building complexes, in terms of kilowatt (kW) that will be allocated to all applicants for electric power consumption in respect of the proposed building or building complexes on their completion.
    Demand factor
    is the ratio of the sum of the maximum demand of a system (or part of a system) to the total connected load on the system (or part of the system) under consideration. Demand factor is always less than one.
    Contract demand
    the maximum demand in kilo Volt Ampere (kVA) (within a consumer’s sanctioned load) agreed to be supplied by the electricity provider or utility in the agreement executed between the user and the utility or electricity provider.
    Construction documents
    drawings or documents, containing information pertaining to building construction processes and approvals, building materials and equipment specification, architectural details etc. required by the authority having jurisdiction.
    Controls or control device
    manually operated or automatic device or software to regulate the operation of building equipment
    Cool roof
    roof with top layer of material that has high solar reflectance and high thermal emittance properties. Cool roof surfaces are characterized by light colors so that heat can be rejected back to the environment.
    Cumulative design EPI
    energy performance index for a building having two or more different functional uses and calculated based on the area weighted average (AWA) method
  • D
  • Daylight area
    the daylight illuminated floor area under horizontal fenestration (skylight) or adjacent to vertical fenestration (window), described as follows
    Horizontal Fenestration
    the area under a skylight, monitor, or sawtooth configuration with an effective aperture greater than 0.001 (0.1%). The daylight area is calculated as the horizontal dimension in each direction equal to the top aperture dimension in that direction plus either the floor-to-ceiling height (H) for skylights, or 1.5 H for monitors, or H or 2H for the sawtooth configuration, or the distance to the nearest 1 meter or higher opaque partition, or one-half the distance to an adjacent skylight or vertical glazing, whichever is least.
    Vertical Fenestration
    the floor area adjacent to side apertures (vertical fenestration in walls) with an effective aperture greater than 0.06 (6%). The daylight area extends into the space perpendicular to the side aperture a distance equal to daylight extension factor (DEF) multiplied by the head height of the side aperture or till higher opaque partition, whichever is less. In the direction parallel to the window, the daylight area extends a horizontal dimension equal to the width of the window plus either 1 meter on each side of the aperture, or the distance to an opaque partition, or one-half the distance to an adjacent skylight or window, whichever is least.
    Daylight Extension Factor (DEF)
    factor to manually calculate the daylight area on floor plates. It is to be multiplied by the head height of windows. It is dependent on orientation and glazing VLT, shading devices adjacent to it and building location.
    Daytime Business Building
    Business building operated typically only during daytime on weekdays upto 12 hours each day.
    Deadband
    the range of values within which a sensed variable can vary without initiating a change in the controlled process.
    Demand
    maximum rate of electricity (kW) consumption recorded for a building or facility during a selected time frame.
    Demand control ventilation (DCV)
    a ventilation system capability that provides automatic reduction of outdoor air intake below design rates when the actual occupancy of spaces served by the system is less than design occupancy
    Design capacity
    output capacity of a mechanical or electrical system or equipment at design conditions
    Design conditions
    specified indoor environmental conditions, such as temperature, humidity and light intensity, required to be produced and maintained by a system and under which the system must operate
    Distribution system
    network or system comprising controlling devices or equipment and distribution channels (cables, coils, ducts, pipes etc.) for delivery of electrical power or, cooled or heated water or air in buildings
    Door
    all operable opening areas, that are not more than one half glass, in the building envelope, including swinging and roll-up doors, fire doors, and access hatches
    Door area
    total area of the door measured using the rough opening and including the door slab and the frame.
  • E
  • Economizer, air
    a duct and damper arrangement with automatic controls that allow a cooling system to supply outdoor air to reduce or eliminate the need for mechanical cooling during mild or cold weather
    Economizer, water
    a system by which the supply air of a cooling system is cooled indirectly with water that is itself cooled by heat or mass transfer to the environment without the use of mechanical cooling
    ECBC Building
    a building that complies with the mandatory requirements of §4 to §7 and also complies either with the prescriptive requirements stated under the ECBC Building categories of §4 to §7, or, with the whole building performance compliance method of §9.
    ECBC+ Building
    a building that complies with the mandatory requirements of §4 to §7 and also complies either with the prescriptive requirements stated under the ECBC+ Building categories of §4 to §7, or, with the whole building performance compliance method of §9. This is a voluntary level of compliance with ECBC.
    Effective aperture
    Visible light transmittance x window-to-wall Ratio. (EA = VLT x WWR)
    Efficacy
    the lumens produced by a lamp plus ballast system divided by the total watts of input power (including the ballast), expressed in lumens per watt
    Efficiency
    performance at a specified rating condition
    Efficiency, thermal
    ratio of work output to heat input
    Efficiency, combustion
    efficiency with which fuel is burned during the combustion process in equipment
    Emittance
    the ratio of the radiant heat flux emitted by a specimen to that emitted by a blackbody at the same temperature and under the same conditions
    Energy
    power derived from renewable or non-renewable resources to provide heating, cooling and light to a building or operate any building equipment and appliances. It has various forms such as thermal (heat), mechanical (work), electrical, and chemical that may be transformed from one into another. Customary unit of measurement is watts (W)
    Energy Conservation Building Code (ECBC)
    the Energy Conservation Building Code as updated from time to time by the Bureau and displayed on its website (www.beeindia.gov.in).
    Energy Efficiency Ratio (EER)
    the ratio of net cooling capacity in W to total rate of electric input in watts under design operating conditions
    Energy recovery system
    equipment to recover energy from building or space exhaust air and use it to treat (pre-heat or pre-cool) outdoor air taken inside the building or space by ventilation systems
    Envelope Performance Factor (EPF)
    value for the building envelope performance compliance option calculated using the procedures specified in 4.3.5 and 4.3.5.1. For the purposes of determining building envelope requirements the classifications are defined as follows
    1. Standard Building EPF
    2. Proposed Building EPF
    Standard Building EPF
    envelope performance factor calculated for the Standard Building using prescriptive requirements for walls, vertical fenestrations and roofs
    Proposed Building EPF
    the building envelope performance factor for the Proposed Building using proposed values for walls, vertical fenestrations and roofs
    Energy Performance Index (EPI)
    of a building means its annual energy consumption in kilowatt-hours per square meter of the area of the building which shall be calculated in the existing or proposed building as per the formula below, =(annual energy consumption in kWh)/(total built-up area (excluding storage area and the parking in the basement)in m2 )
    EPI Ratio
    of a building means the ratio of the EPI of the Proposed Building to the EPI of the Standard Building.
    Equipment
    mechanical, electrical or static devices for operating a building, including but not limited to those required for providing cooling, heating, ventilation, lighting, service hot water, vertical circulation
    Equipment, existing
    equipment previously installed in an existing building
    Equivalent SHGC
    SHGC for a fenestration with a permanent external shading projection. It is calculated using the Projection Factor (PF) of the permanent external shading projection and Shading Equivalent Factor (SEF) listed in §4.3.1.
    Exemption
    any exception allowed to compliance with ECBC requirements
  • F
  • Fan system power
    sum of the nominal power demand (nameplate W or HP) of motors of all fans that are required to operate at design conditions to supply air from the heating or cooling source to the conditioned space(s) and return it to the point where is can be exhausted to outside the building.
    Fenestration
    all areas (including the frames) in the building envelope that let in light, including windows, plastic panels, clerestories, skylights, glass doors that are more than one-half glass, and glass block walls.
    Skylight
    a fenestration surface having a slope of less than 60 degrees from the horizontal plane. Other fenestration, even if mounted on the roof of a building, is considered vertical fenestration.
    Vertical fenestration
    all fenestration other than skylights. Trombe wall assemblies, where glazing is installed within 300 mm of a mass wall, are considered walls, not fenestration.
    Fenestration area
    total area of the fenestration measured using the rough opening and including the glazing, sash, and frame. For doors where the glazed vision area is less than 50% of the door area, the fenestration area is the glazed vision area. For all other doors, the fenestration area is the door area.
    Finished floor level
    level of floor achieved after finishing materials have been added to the subfloor or rough floor or concrete floor slab.
    Fossil fuel
    fuel derived from a hydrocarbon deposit such as petroleum, coal, or natural gas derived from living matter of a previous geologic time
    Fuel
    a material that may be used to produce heat or generate power by combustion
    Fuel utilization efficiency (FUE)
    a thermal efficiency measure of combustion equipment like furnaces, boilers, and water heaters
  • G
  • Gathering hall (Type of Assembly)
    any building, its lobbies, rooms and other spaces connected thereto, primarily intended for assembly of people, but which has no theatrical stage or permanent theatrical and/or cinematographic accessories and has gathering space for greater or equal to 100 persons, for example, stand-alone dance halls, stand-alone night clubs, halls for incidental picture shows, dramatic, theatrical or educational presentation, lectures or other similar purposes having no theatrical stage except a raised platform and used without permanent seating arrangement; art galleries, community halls, marriage halls, places of worship, museums, stand-alone lecture halls, passenger terminals and heritage and archeological monuments, pool and billiard parlors, bowling alleys, community halls, courtrooms, gymnasiums, indoor swimming pools, indoor tennis court, any indoor stadium for sports and culture, auditoriums
    Grade
    finished ground level adjoining a building at all exterior walls
    Guest room
    any room or rooms used or intended to be used by a guest for sleeping purposes
  • H
  • Habitable spaces
    space in a building or structure intended or used for working, meeting, living, sleeping, eating, or cooking. Bathrooms, water closet compartments, closets, halls, storage or utility space, and similar areas are not considered habitable spaces.
    Hospitals and sanatoria (Healthcare)
    Any building or a group of buildings under single management, which is used for housing persons suffering from physical limitations because of health or age and those incapable of self-preservation, for example, any hospitals, infirmaries, sanatoria and nursing homes.
    HVAC system
    equipment, distribution systems, and terminal devices that provide, either collectively or individually, the processes of heating, ventilating, or air conditioning to a building or parts of a building.
    Hyper Markets (Type F of Shopping Complex)
    large retail establishments that are a combination of supermarket and department stores. They are considered as a one-stop shop for all needs of the customer.
  • I
  • Infiltration
    uncontrolled inward air leakage through cracks and crevices in external surfaces of buildings, around windows and doors due to pressure differences across these caused by factors such as wind or indoor and outside temperature differences (stack effect), and imbalance between supply and exhaust air systems
    Installed interior lighting power
    power in watts of all permanently installed general, task, and furniture lighting systems and luminaires
    Integrated part-load value (IPLV)
    weighted average efficiency of chillers measured when they are operating at part load conditions (less than design or 100% conditions). It is more realistic measurement of chiller efficiency during its operational life.
  • K
  • Kilovolt-ampere (kVA)
    where the term “kilovolt-ampere” (kVA) is used in this Code, it is the product of the line current (amperes) times the nominal system voltage (kilovolts) times 1.732 for three-phase currents. For single-phase applications, kVA is the product of the line current (amperes) times the nominal system voltage (kilovolts).
    Kilowatt (kW)
    the basic unit of electric power, equal to 1000 W.
  • L
  • Labeled
    equipment or materials to which a symbol or other identifying mark has been attached by the manufacturer indicating compliance with specified standard or performance in a specified manner.
    Lamp
    a device for giving light consisting of electric bulb with its holder and shade or cover
    Lighted floor area, gross
    gross area of lighted floor spaces
    Lighting, emergency
    battery backed lighting that provides illumination only when there is a power outage and general lighting luminaries are unable to function.
    Lighting, general
    lighting that provides a substantially uniform level of illumination throughout an area. General lighting shall not include decorative lighting or lighting that provides a dissimilar level of illumination to serve a specialized application or feature within such area.
    Lighting system
    a group of luminaires circuited or controlled to perform a specific function.
    Lighting power allowance
    1. Interior lighting power allowance: the maximum lighting power in watts allowed for the interior of a building
    2. Exterior lighting power allowance: the maximum lighting power in watts allowed for the exterior of a building
    Lighting Power Density (LPD)
    maximum lighting power per unit area of a space as per its function or building as per its classification.
    Low energy comfort systems
    space conditioning or ventilation systems that are less energy intensive then vapor compression based space condition systems. These primarily employ alternate heat transfer methods or materials (adiabatic cooling, radiation, desiccant, etc.), or renewable sources of energy (solar energy, geo-thermal) so that minimal electrical energy input is required to deliver heating or cooling to spaces.
    Luminaires
    a complete lighting unit consisting of a lamp or lamps together with the housing designed to distribute the light, position and protect the lamps, and connect the lamps to the power supply.
  • M
  • Man-made daylight obstruction
    any permanent man-made object (equipment, adjacent building) that obstructs sunlight or solar radiation from falling on a portion or whole of a building’s external surface at any point of time during a year is called as a man-made sunlight obstructer.
    Manual (non-automatic)
    requiring personal intervention for control. Non-automatic does not necessarily imply a manual controller, only that personal intervention is necessary.
    Manufacturing processes
    processes through which raw material is converted into finished goods for commercial sale using machines, labor, chemical or biological processes, etc.
    Manufacturer
    company or person or group of persons who produce and assemble goods or purchases goods manufactured by a third party in accordance with their specifications.
    Mean temperature
    average of the minimum daily temperature and maximum daily temperature.
    Mechanical cooling
    reducing the temperature of a gas or liquid by using vapor compression, absorption, and desiccant dehumidification combined with evaporative cooling, or another energy-driven thermodynamic cycle. Indirect or direct evaporative cooling alone is not considered mechanical cooling.
    Metering
    practice of installing meters in buildings to acquire data for energy consumption and other operational characteristics of individual equipment or several equipment grouped on basis of their function (lighting, appliances, chillers, etc.). Metering is done in buildings to monitor their energy performance.
    Mixed mode air-conditioned building
    building in which natural ventilation is employed as the primary mode of ventilating the building, and air conditioning is deployed as and when required.
    Mixed use development
    a single building or a group of buildings used for a combination of residential, commercial, business, educational, hospitality and assembly purposes
  • N
  • National Building Code 2016 (NBC)
    model building code that provides guidelines for design and construction of buildings. In this code, National Building Code 2016 refers to the latest version by the Bureau of Indian Standards.
    Natural daylight obstruction
    any natural object, like tree, hill, etc., that obstructs sunlight from falling on part or whole of a building’s external surface at any point of time during a year and casts a shadow on the building surface.
    Naturally ventilated building
    a building that does not use mechanical equipment to supply air to and exhaust air from indoor spaces. It is primarily ventilated by drawing and expelling air through operable openings in the building envelope.
    Non-cardinal directions
    any direction which is not a cardinal direction, i.e. perfect north, south, east, or west, is termed as non-cardinal direction.
    No Star hotel (Type of Hospitality)
    any building or group of buildings under the same management, in which separate sleeping accommodation on commercial basis, with or without dining facilities or cooking facilities, is provided for individuals. This includes lodging rooms, inns, clubs, motels, no star hotel and guest houses and excludes residential apartments rented on a lease agreement of 4 months or more. These shall also include any building in which group sleeping accommodation is provided, with or without dining facilities for persons who are not members of the same family, in one room or a series of adjoining rooms under joint occupancy and single management, for example, school and college dormitories, students, and other hostels and military barracks.
  • O
  • Occupant sensor
    a device that detects the presence or absence of people within an area and causes lighting, equipment, or appliances to be dimmed, or switched on or off accordingly.
    Opaque assembly or opaque construction
    surface of the building roof or walls other than fenestration and building service openings such as vents and grills.
    Opaque external wall
    external wall composed of materials which are not transparent or translucent, usually contains the structural part of the building, and supports the glazed façade. This type may be composed of one or more materials.
    Open Gallery Mall (Type of Shopping Complex)
    a large retail complex containing a variety of stores and often restaurants and other business establishments housed in a series of connected or adjacent buildings or in a single large building. The circulation area and atrium of the open gallery mall is an unconditioned space and is open to sky.
    Orientation
    the direction a building facade faces, i.e., the direction of a vector perpendicular to and pointing away from the surface of the facade. For vertical fenestration, the two categories are north-oriented and all other.
    Outdoor (outside) air
    air taken from the outside the building and has not been previously circulated through the building.
    Out-patient Healthcare (Type of Healthcare)
    any building or a group of buildings under single management, which is used only for treating persons requiring treatment or diagnosis of disease but not requiring overnight or longer accommodation in the building during treatment or diagnosis.
    Overcurrent
    any current in excess of the rated current of the equipment of the ampacity of the conductor. It may result from overload, short circuit, or ground fault.
    Owner
    a person, group of persons, company, trust, institute, Registered Body, state or central Government and its attached or sub-ordinate departments, undertakings and like agencies or organization in whose name the property stands registered in the revenue records for the construction of a building or building complex
  • P
  • Party wall
    a firewall on an interior lot line used or adapted for joint service between two buildings.
    Permanently installed
    equipment that is fixed in place and is not portable or movable.
    Plenum
    a compartment or chamber to which one or more ducts are connected, that forms a part of the air distribution system, and that is not used for occupancy or storage.
    Plug loads
    energy used by products that are powered by means of an AC plug. This term excludes building energy that is attributed to major end uses specified in § 5, § 6, § 7 (like HVAC, lighting, water heating, etc.).
    Pool
    any structure, basin, or tank containing an artificial body of water for swimming, diving, or recreational bathing. The terms include, but no limited to, swimming pool, whirlpool, spa, hot tub.
    Potential daylit time
    amount of time in a day when there is daylight to light a space adequately without using artificial lighting. Potential daylit time is fixed for 8 hours per day i.e. from 09:00 AM to 5:00 PM local time, resulting 2920 hours in total for all building types except for Type E-1 - Educational, which shall be analyzed for 7 hours per day i.e. from 08:00 AM to 3:00 PM local time.
    Primary inter-cardinal direction
    any of the four points of the compass, midway between the cardinal points; northeast, southeast, southwest, or northwest are called primary inter-cardinal direction.
    Process load
    building loads resulting from the consumption or release of energy due to industrial processes or processes other than those for providing space conditioning, lighting, ventilation, or service hot water heating.
    Projection factor, overhang
    It is the ratio of the horizontal depth of the external shading projection to the sum of the height of the fenestration and the distance from the top of the fenestration to the bottom of the farthest point of the external shading projection, in consistent units.
    Projection factor, side fin
    It is the ratio of the horizontal depth of the external shading projection to the distance from the window jamb to the farthest point of the external shading projection, in consistent units.
    Projection Factor, overhang and side fin
    average of ratio projection factor for overhang only and projection factor of side fin only.
    Proposed Building
    is consistent with the actual design of the building and complies with all the mandatory requirements of ECBC.
    Proposed Design
    a computer model of the proposed building, consistent with its actual design, which complies with all the mandatory requirements of ECBC.
  • R
  • R-value (thermal resistance)
    the reciprocal of the time rate of heat flow through a unit area induced by a unit temperature difference between two defined surfaces of material or construction under steady-state conditions. Units of R value are m2.K /W.
    Readily accessible
    capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, chairs, etc. In public facilities, accessibility may be limited to certified personnel through locking covers or by placing equipment in locked rooms.
    Recirculating system
    a domestic or service hot water distribution system that includes a close circulation circuit designed to maintain usage temperatures in hot water pipes near terminal devices (e.g., lavatory faucets, shower heads) in order to reduce the time required to obtain hot water when the terminal device valve is opened. The motive force for circulation is either natural (due to water density variations with temperature) or mechanical (recirculation pump).
    Renewable Energy Generating Zone
    a contiguous or semi-contiguous area, either on rooftop or elsewhere within site boundary, dedicated for installation of renewable energy systems.
    Resort (Type of Hospitality)
    commercial establishments that provide relaxation and recreation over and above the accommodation, meals and other basic amnesties. The characteristics of resort are as below –
    1. Includes 1 or more recreation(s) facility like spa, swimming pool, or any sport;
    2. Is located in the midst of natural and picturesque surroundings outside the city;
    3. Comprises of 2 or more blocks of buildings within the same site less than or equal to 3 floors (including the ground floor).
    Reset
    automatic adjustment of the controller set point to a higher or lower value.
    Roof
    the upper portion of the building envelope, including opaque areas and fenestration, that is horizontal or tilted at an angle of less than 60° from horizontal. This includes podium roof as well which are exposed to direct sun rays.
    Roof area, gross
    the area of the roof measured from the exterior faces of walls or from the centerline of party walls
  • S
  • Service
    the equipment for delivering energy from the supply or distribution system to the premises served.
    Service water heating equipment
    equipment for heating water for domestic or commercial purposes other than space heating and process requirements.
    Set point
    the desired temperature (°C) of the heated or cooled space that must be maintained by mechanical heating or cooling equipment.
    Shading Coefficient (SC)
    measure of thermal performance of glazing. It is the ratio of solar heat gain through glazing due to solar radiation at normal incidence to that occurring through 3 mm thick clear, double-strength glass. Shading coefficient, as used herein, does not include interior, exterior, or integral shading devices.
    Shading Equivalent Factor
    coefficient for calculating effective SHGC of fenestrations shaded by overhangs or side fins.
    Shopping Mall (Shopping Complex)
    a large retail complex containing a variety of stores and often restaurants and other business establishments housed in a series of connected or adjacent buildings or in a single large building. The circulation area and atrium of the mall is an enclosed space covered completely by a permanent or temporary structure.
    Simulation program
    software in which virtual building models can be developed to simulate the energy performance of building systems and daylighting analysis.
    Single-zone system
    an HVAC system serving a single HVAC zone.
    Site-recovered energy
    waste energy recovered at the building site that is used to offset consumption of purchased fuel or electrical energy supplies.
    Slab-on-grade floor
    floor slab of the building that is in contact with ground and that is either above grade or is less than or equal to 300 mm below the final elevation of the nearest exterior grade.
    Solar energy source
    source of thermal, chemical, or electrical energy derived from direction conversion of incident solar radiation at the building site.
    Solar Heat Gain Coefficient (SHGC)
    the ratio of the solar heat gain entering the space through the fenestration area to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and absorbed solar radiation, which is then reradiated, conducted, or convected into the space.
    Solar Reflectance
    ratio of the solar radiation reflected by a surface to the solar radiation incident upon it.
    Space
    an enclosed area within a building. The classifications of spaces are as follows for purpose of determining building envelope requirements
    1. Conditioned space
    2. Semi-heated space
    3. Non-conditioned space
    Conditioned space
    a cooled space, heated space, or directly conditioned space.
    Semi-heated space
    an enclosed space within a building that is heated by a heating system whose output capacity is greater or equal to 10.7 W/m2 but is not a conditioned space.
    Non-conditioned space
    an enclosed space within a building that is not conditioned space or a semi-heated space. Crawlspaces, attics, and parking garages with natural or mechanical ventilation are not considered enclosed spaces.
    Star Hotels/motels (Star Hotel)
    any building or group of buildings under single management and accredited as a starred hotel by the Hotel and Restaurant Approval and Classification Committee, Ministry of Tourism, in which sleeping accommodation, with or without dining facilities is provided.
    Stand-alone Retail (Shopping Complex)
    a large retail store owned or sublet to a single management which may offer customers a variety of products under self-branding or products of different brands. The single management shall have a complete ownership of all the spaces of the building and no space within the building is further sold or sublet to a different management.
    Standard Building
    a building that minimally complies with all the mandatory and prescriptive requirements of Energy Conservation Building Code and has same floor area, gross wall area, and gross roof area of the Proposed Building.
    Standard Design
    a computer model of a hypothetical building, based on actual building design, that fulfils all the mandatory requirements and minimally complies with the prescriptive requirements of ECBC, as described in the Whole Building Performance method.
    Story
    portion of a building that is between one finished floor level and the next higher finished floor level or building roof. Basement and cellar shall not be considered a story.
    Summer Solar Insolation
    measure of solar radiation energy received on a given surface area from the month of March to October within the same calendar year. Units of measurement are watts per square meter (W/m²) or kilowatt-hours per square meter per day (kW•h/(m²•day)) (or hours/day).
    SuperECBC Building
    a building that complies with the mandatory requirements of §4 to §7 and also complies either with the prescriptive requirements stated under the SuperECBC Building categories of §4 to §7, or, with the whole building performance compliance method of §9. This is a voluntary level of compliance with ECBC.
    Super Market (Shopping Complex)
    supermarkets are large self-service grocery stores that offer customers a variety of foods and household supplies. The merchandise is organized into an organized aisle format, where each aisle has only similar goods placed together.
    System
    a combination of equipment and auxiliary devices (e.g., controls, accessories, interconnecting means, and terminal elements) by which energy is transformed so it performs a specific function such as HVAC, service water heating, or lighting.
    System Efficiency
    the system efficiency is the ratio of annual kWh electricity consumption of equipment of water cooled chilled water plant (i.e. chillers, chilled and condenser water pumps, cooling tower) to chiller thermal kWh used in a building.
    System, existing
    a system or systems previously installed in an existing building.
  • T
  • Tenant lease agreement
    The formal legal document entered into between a Landlord and a Tenant to reflect the terms of the negotiations between them; that is, the lease terms have been negotiated and agreed upon, and the agreement has been reduced to writing. It constitutes the entire agreement between the parties and sets forth their basic legal rights.
    Tenant leased area
    area of a building that is leased to tenant(s) as per the tenant lease agreement.
    Terminal device
    a device through which heated or cooled air is supplied to a space to maintain its temperature. It usually contains dampers and heating and cooling coils. Or a device by which energy form a system is finally delivered, e.g., registers, diffusers, lighting fixtures, faucets, etc.
    Theater or motion picture hall (Type of Assembly)
    any building primarily meant for theatrical or operatic performances and which has a stage, proscenium curtain, fixed or portable scenery or scenery loft, lights, mechanical appliances or other theatrical accessories and equipment for example, theaters, motion picture houses, auditoria, concert halls, television and radio studios admitting an audience and which are provided with fixed seats.
    Thermal block
    a collection of one or more HVAC zones grouped together for simulation purposes. Spaces need not be contiguous to be combined within a single thermal block.
    Thermal comfort conditions
    conditions that influence thermal comfort of occupants. Environmental conditions that influence thermal comfort air and radiant temperature, humidity, and air speed.
    Thermostat
    device containing a temperature sensor used to automatically maintain temperature at a desirable fixed or adjustable set point in a space.
    Tinted
    (as applied to fenestration) bronze, green, or grey coloring that is integral with the glazing material. Tinting does not include surface applied films such as reflective coatings, applied either in the field or during the manufacturing process.
    Transformer
    a piece of electrical equipment used to convert electric power from one voltage to another voltage.
    Transformer losses
    electrical losses in a transformer that reduces its efficiency.
    Transport Buildings (Assembly)
    any building or structure used for the purpose of transportation and transit like airports, railway stations, bus stations, and underground and elevated mass rapid transit system example, underground or elevated railways.
  • U
  • Unconditioned buildings
    building in which more than 90% of spaces are unconditioned spaces.
    Unconditioned space
    mechanically or naturally ventilated space that is not cooled or heated by mechanical equipment.
    Universities and all others coaching/training institutions (Educational)
    a building or a group of buildings, under single management, used for imparting education to students numbering more than 100 or public or private training institution built to provide training/coaching etc.
    Useful Daylight Illuminance
    percentage of annual daytime hours that a given point on a work plane height of 0.8 m above finished floor level receives daylight between 100 lux to 2,000 lux.
    U-factor (Thermal Transmittance)
    heat transmission in unit time through unit area of a material or construction and the boundary air films, induced by unit temperature difference between the environments on each side. Unit of U value is W/m22.K.
  • V
  • Variable Air Volume (VAV) system
    HVAC system that controls the dry-bulb temperature within a space by varying the volumetric flow of heated or cooled air supplied to the space
    Vegetative roofs
    also known as green roofs, they are thin layers of living vegetation installed on top of conventional flat or sloping roofs.
    Ventilation
    the process of supplying or removing air by natural or mechanical means to or from any space. Such air is not required to have been conditioned.
    Vision Windows
    windows or area of large windows that are primarily for both daylight and exterior views. Typically, their placement in the wall is between 1 meter and 2.2 meter above the floor level.
  • W
  • Wall
    that portion of the building envelope, including opaque area and fenestration, that is vertical or tilted at an angle of 60° from horizontal or greater. This includes above and below-grade walls, between floor spandrels, peripheral edges of floors, and foundation walls.
    1. Wall, above grade: a wall that is not below grade
    2. Wall, below grade: that portion of a wall in the building envelope that is entirely below the finish grade and in contact with the ground
    Wall area, gross
    the overall area off a wall including openings such as windows and doors measured horizontally from outside surface to outside service and measured vertically from the top of the floor to the top of the roof. If roof insulation is installed at the ceiling level rather than the roof, then the vertical measurement is made to the top of the ceiling. The gross wall area includes the area between the ceiling and the floor for multi-story buildings.
    Water heater
    vessel in which water is heated and withdrawn for use external to the system.
  • Z
  • Zone, HVAC
    a space or group of spaces within a building with heating and cooling requirements that are sufficiently similar so that desired conditions (e.g., temperature) can be maintained throughout using a single sensor (e.g., thermostat or temperature sensor).
    Zone, Critical
    a zone serving a process where reset of the zone temperature setpoint during a demand shed event might disrupt the process, including but not limited to data centers, telecom and private branch exchange (PBX) rooms, and laboratories.
    Zone, Non-Critical
    a zone that is not a critical zone.

Whole Building Performance Method

9.1.1 Scope

The Whole Building Performance Method is an alternative to the Prescriptive Method compliance path contained in §4 through §7 of this Code. It applies to all building types covered by the Code as mentioned in §2.5.

9.1.2 Compliance

A building complies with the Code using the Whole Building Performance (WBP) Method, when the estimated EPI Ratio is equal to or less than 1, even though it may not comply with the specific provisions of the prescriptive requirements in §4 trough §7. The mandatory requirements of §4 through §7 (§4.2, §5.2, §6.2, and §7.2) shall be met when using the WBP Method.

9.1.3 Annual Energy Use

Annual energy use for the purposes of the WBP Method shall be calculated in kilowatt-hours (kWh) of electricity use per year per unit area. Energy sources other than electricity that are used in the building shall be converted to kWh of electric energy at the rate of 0.75 kWh per megajoule.

Note: The annual energy use calculation as per the Whole Building Performance Method is not a prediction of the actual energy use of the building once it gets operational. Actual energy performance of a building depends on a number of factors like weather, occupant behaviour, equipment performance and maintenance, among others, which are not covered by this Code.

9.1.4 Trade-offs Limited to Building Permit

The WBP Method may be used for building permit applications that include less than the whole building; however, any design parameters that are not part of the building permit application shall be identical for both the Proposed Design and the Standard Design. Future improvements to the building shall comply with both the mandatory and prescriptive requirements of concurrent code.

9.1.5 Documentation Requirements

Compliance shall be documented and compliance forms shall be submitted to the authority having jurisdiction. The information submitted shall include, at a minimum, the following:

  1. Summary describing the results of the analysis, including the annual energy use for the Proposed Design and the Standard Design, and software used.
  2. Brief description of the project with location, number of stories, space types, conditioned and unconditioned areas, hours of operation.
  3. List of the energy-related building features of the Proposed Design. This list shall also document features different from the Standard Design.
  4. List showing compliance with the mandatory requirements of this code.
  5. The input and output report(s) from the simulation program including a breakdown of energy usage by at least the following components: lights, internal equipment loads, service water heating equipment, space heating equipment, space cooling and heat rejection equipment, fans, and other HVAC equipment (such as pumps). The output reports shall also show the number of hours any loads are not met by the HVAC system for both the Proposed Design and Standard Design.
  6. Explanation of any significant modelling assumptions made.
  7. Explanation of any error messages noted in the simulation program output.
  8. Building floor plans, building elevations, and site plan.

9.2 Mandatory Requirements

All requirements of §4.2, §5.2, §6.2, and §7.2 shall be met. These sections contain the mandatory provisions of the Code and are prerequisites for demonstrating compliance using the WBP Method.

9.3.1 Energy Simulation Program

The simulation software shall be a computer-based program for the analysis of energy consumption in buildings and be approved by the authority having jurisdiction. The simulation program shall, at a minimum, have the ability to model the following:

  1. Energy flows on an hourly basis for all 8,760 hours of the year,
  2. Hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat set points, and HVAC system operation, defined separately for each day of the week and holidays,
  3. Thermal mass effects,
  4. Ten or more thermal zones,
  5. Part-load and temperature dependent performance of heating and cooling equipment,
  6. Air-side and water-side economizers with integrated control.

In addition to the above, the simulation tool shall be able to produce hourly reports of energy use by energy source and shall have the capability to performing design load calculations to determine required HVAC equipment capacities, air, and water flow rates in accordance with §5 for both the proposed and Standard building designs.

The simulation program shall be tested according to ASHRAE Standard 140 Method of Test for the Evaluation of Building Energy Analysis Computer Programs (ANSI approved) and the results shall be furnished by the software provider.

9.3.2 Climate Data

The simulation program shall use hourly values of climatic data, such as temperature and humidity, from representative climatic data for the city in which the Proposed Design is to be located. For cities or urban regions with several climate data entries, and for locations where weather data are not available, the designer shall select available weather data that best represent the climate at the construction site.

9.3.3 Compliance Calculations

The Proposed Design and Standard Design shall be calculated using the following:

  1. Same simulation program,
  2. Same weather data, and
  3. Identical building operation assumptions (thermostat set points, schedules, equipment and occupant loads, etc.) unless an exception is allowed by this Code or the authority having jurisdiction for a given category.

9.4.1 Energy Simulation Model

The simulation model for calculating the Proposed Design and the Standard Design shall be developed in accordance with the requirements in Table 9-1. The Standard Design is based on the mandatory and prescriptive requirements of the ECBC compliant building. The Standard Design will be the same for all compliance levels (ECBC, ECBC+, Super ECBC).

Table 9-1 Modelling Requirements for Calculating Proposed and Standard Design
1. Design Model
Proposed Design
  1. The simulation model of the Proposed Design shall be consistent with the design documents, including proper accounting of fenestration and opaque envelope types and area; interior lighting power and controls; HVAC system types, sizes, and controls; and service water heating systems and controls.
  2. When the whole building performance method is applied to buildings in which energy-related features have not been designed yet (e.g., a lighting system), those yet-to-be-designed features shall be described in the Proposed Design so that they minimally comply with applicable mandatory and prescriptive requirements of §4.2, §5.2 , §6.2, and §7.2 and §4.3, §5.3, and §6.3 respectively.
Standard Design
The Standard Design shall be developed by modifying the Proposed Design as described in this table. Unless specified in this table, all building systems and equipment shall be modeled identically in the Standard Design and Proposed Design.
2. Space Use Classification
Proposed Design
The building type or space type classifications shall be chosen in accordance with §2.5. More than one building type category may be used in a building if it is a mixed-use facility.
Standard Design
Same as Proposed Design.
3. Schedules
Proposed Design
Operational schedules (hourly variations in occupancy, lighting power, equipment power, HVAC equipment operation, etc.) suitable for the building and/or space type shall be modeled for showing compliance. Schedules must be modeled as per §9.6. In case a schedule for an occupancy type is missing in §9.6, appropriate schedule may be used. Temperature and humidity schedules and set points shall be identical in the Standard and Proposed Designs. Temperature control/thermostat throttling ranges shall also be modeled identically in both the Designs.
Standard Design
Same as Proposed Design.
Exception: Schedules may be allowed to differ between the Standard and proposed models wherever it is necessary to model nonstandard efficiency measures and/or measures which can be best approximated by a change in schedule. Measures that may warrant a change in operating schedules include but are not limited to automatic controls for lighting, natural ventilation, demand controlled ventilation systems, controls for service water heating load reduction. Schedule change is not allowed for manual controls under any category. This is subject to approval by the authority having jurisdiction.
4. Building Envelope
Proposed Design
All components of the building envelope in the Proposed Design shall be modeled as shown on architectural drawings or as installed for existing building envelopes. Exceptions: The following building elements are permitted to differ from architectural drawings.
  1. Any envelope assembly that covers less than 5% of the total area of that assembly type (e.g., exterior walls) need not be separately described. If not separately described, the area of an envelope assembly must be added to the area of the adjacent assembly of that same type.
  2. Exterior surfaces whose azimuth orientation and tilt differ by no more than 45 degrees and are otherwise the same may be described as either a single surface or by using multipliers.
  3. For exterior roofs, other than roofs with ventilated attics, the reflectance and emittance of the roof surface shall be modeled in accordance with §4.3.1.1.
  4. Manually operated fenestration shading devices such as blinds or shades shall not be modeled. Permanent shading devices such as fins, overhangs, and light shelves shall be modeled.
  5. The exterior roof surface shall be modeled using the solar reflectance in accordance with ASTM E903-96 and thermal emittance determined in accordance with ASTM E408-71. Where cool roof is proposed, emittance and reflectance shall be modeled as per ASTM E408-71 and ASTM E903-96 respectively. Where cool roof is not proposed, the exterior roof surface shall be modeled as per §4.3.1.1 i.e, the exterior roof surface shall be modeled with a solar reflectance of 0.7 and a thermal emittance of 0.75.
Standard Design
The Standard Design shall have identical conditioned floor area and identical exterior dimensions and orientations as the Proposed Design, except as noted in (a), (b), (c), (d) and (e) below.
  1. Orientation. The Standard Design performance shall be generated by simulating the building with its actual orientation and again after rotating the entire building 90, 180, 270 degrees, then averaging the results. The building shall be modeled so that it does not shade itself.
  2. Opaque assemblies such as roof, floors, doors, and walls shall be modeled with the maximum U-factor allowed in §4.3.1 and §4.3.2.
  3. Fenestration. Fenestration areas shall equal that in the Proposed Design or 40% of gross above grade wall area, whichever is smaller, and shall be distributed on each face in the same proportions as in the Proposed Design No shading projections are to be modeled; fenestration shall be assumed to be flush with the exterior wall or roof. Manually operated fenestration shading devices such as blinds or shades shall not be modeled. Fenestration U-factor shall be the maximum allowed for the climate, and the solar heat gain coefficient shall be the maximum allowed for the climate and orientation.
  4. Skylight areas shall equal that in the Proposed Design or 5% of gross roof area, whichever is smaller.
  5. Roof Solar Reflectance and Thermal Emittance: The exterior roof surfaces shall be modeled using a solar reflectance of 0.70 and a thermal emittance of 0.75 as per §4.3.1.1.
5. Lighting
Proposed Design
Lighting power in the Proposed Design shall be determined as follows: Where a complete lighting system exists, the actual lighting power shall be used in the model. Where a lighting system has been designed, lighting power shall be determined in accordance with either §6.3.4. Where no lighting exists, or is specified, lighting power shall be determined in accordance with the §6.3.2 or §6.3.3 for the appropriate building type. Lighting system power shall include all lighting system components shown or provided for on plans (including lamps, ballasts, task fixtures, and furniture-mounted fixtures). Lighting power for parking garages, exterior spaces and building facades shall be modeled. Minimum Lighting controls, as per the ECBC requirements of §6.2.1, shall be modeled in the Proposed case. Automatic daylighting controls shall be modeled directly in the software or through schedule adjustments determined by a separate daylight analysis approved by the authority having jurisdiction. Other automatic lighting controls shall be modeled directly in the software by adjusting the lighting power as per Table 9-4.
Standard Design
Interior lighting power in the Standard Design shall be determined using the same categorization procedure (building area or space function) and categories as the Proposed Design with lighting power set equal to the maximum allowed for the corresponding method and category in either §6.3.2 or §6.3.3. Power for fixtures not included in the lighting power density calculation shall be modeled identically in the Proposed Design and Standard Design. Lighting controls shall be as per the ECBC requirements of §6.2.1.
Exterior lighting power in the standard design shall be set equal to the maximum allowed in §6.3.5
6. HVAC Thermal Zones
Proposed Design
HVAC Zones Designed: Where HVAC zones are defined on design drawings, each HVAC zone shall be modeled as a separate thermal block. Exception: Identical zones (similar occupancy and usage, similar internal loads, similar set points and type of HVAC system, glazed exterior walls face the same orientation or vary by less than 45°) may be combined for simplicity. HVAC Zones Not Designed: Where HVAC zones are not defined on design drawings, HVAC zones shall be defined based on similar occupancy and usage, similar internal loads, similar set points and type of HVAC system, glazed exterior walls that face the same orientation or vary by less than 45° in combination with the following rules: Perimeter Core Zoning: Separate thermal block shall be modeled for perimeter and core spaces. Perimeter spaces are defined as spaces located within 5 meters of an exterior or semi exterior wall. Core spaces are defined as spaces located greater than 5 meters of an exterior or semi exterior wall. Separate thermal blocks shall be modeled for floors in contact with ground and for floors which have a ceiling/roof exposure to the ambient.
Standard Design
Same as Proposed Design
7. HVAC Systems
Proposed Design
The HVAC system type and all related performance parameters, such as equipment capacities and efficiencies, in the Proposed Design shall be determined as follows:
  1. Where a complete HVAC system exists, the model shall reflect the actual system type using actual component capacities and efficiencies.
  2. Where an HVAC system has been designed, the HVAC model shall be consistent with design documents. Mechanical equipment efficiencies shall be adjusted from actual design conditions to the rating conditions specified in §5, if required by the simulation model.
  3. Where no heating system has been specified, the heating system shall be assumed to be electric. The system characteristics shall be identical to the system modeled in the Standard Design.
  4. Where no cooling system has been specified, the cooling system and its characteristics shall be identical to the system modeled in the Standard Design.
Standard Design
The HVAC system type shall be as per Table 9-2 and related performance parameters for the Standard Design shall be determined from requirements of §9.4.2. Equipment performance shall meet the requirements of §5 for code compliant building.
8. Service Hot Water
Proposed Design
The service hot water system type and all related performance parameters, such as equipment capacities and efficiencies, in the Proposed Design shall be determined as follows:
  1. Where a complete service hot water system exists, the model shall reflect the actual system type using actual component capacities and efficiencies.
  2. Where a service hot water system has been designed, the service hot water model shall be consistent with design documents.
  3. Where no service hot water system exists, or is specified, no service hot water heating shall be modeled.
Standard Design
The service water heating system shall be of the same type as the Proposed Design. For residential facilities, hotels and hospitals the Standard Design shall have a solar hot water system capable of meeting 20% of the hot water demand. Systems shall meet the efficiency requirements of §5.2.7.2.
9. Miscellaneous Loads
Proposed Design
Receptacle, motor, and process loads shall be modeled and estimated based on the building type or space type category. These loads shall be included in simulations of the building and shall be included when calculating the Standard Design and Proposed Design. All end-use load components within and associated with the building shall be modeled, unless specifically excluded by this Table, but not limited to, exhaust fans, parking garage ventilation fans, exterior building lighting, swimming pool heaters and pumps, elevators and escalators, refrigeration equipment, and cooking equipment.
Standard Design
Receptacle, motor and process loads shall be modeled the same as the Proposed Design.
10. Modelling Limitations to the Simulation Program
Proposed Design
If the simulation program cannot model a component or system included in the Proposed Design, one of the following methods shall be used with the approval of the authority having jurisdiction:
  1. Ignore the component if the energy impact on the trade-offs being considered is not significant.
  2. Model the component substituting a thermodynamically similar component model.
  3. Model the HVAC system components or systems using the HVAC system of the Standard Design in accordance with Section 6 of this table.
Whichever method is selected, the component shall be modeled identically for both the Proposed Design and Standard Design models.
Standard Design
Same as Proposed Design.
Table 9-2 HVAC Systems Map for Standard Design
Hotel/Motel, Hospital Patient Rooms, Hotel Guest Rooms, Resorts, Villas, Sleeping Quarters in Mixed-use Buildings, Schools, Classrooms/Lecture Rooms1 Buildings with Less than or Equal to 12,500 m2 of Conditioned Area Buildings with More than 12,500m2 of Conditioned Area Data Centre/Server/Computer Rooms
Name System A System B System C System D
System Type2 Split AC VRF : Variable Refrigerant Flow VAV: Central cooling plant with variable volume AHU3 Computer Room air conditioners
Fan Control Constant Volume Constant volume Variable volume Constant volume
Cooling Type Direct expansion with air cooled condenser Direct expansion with air cooled condenser Chilled Water with water cooled condenser Direct expansion with air cooled condenser
Heating Type 1. Heat Pump: Where no heating system has been specified or where an electric heating system has been specified in the Proposed Design
2. Fossil Fuel Boiler, Fossil/Electric Hybrid: Where a heating system exists and a fossil fuel hot water boiler has been specified in the Proposed Design
1. Heat Pump: Where no heating system has been specified or where an electric heating system has been specified in the Proposed Design
2. Fossil Fuel Boiler, Fossil/Electric Hybrid: Where a heating system exists and a fossil fuel hot water boiler has been specified in the Proposed Design
1. Electric resistance: Where no heating system has been specified or where an electric heating system has been specified in the Proposed Design
2. Fossil Fuel Boiler, Fossil/Electric Hybrid: Where a heating system exists and a fossil fuel hot water boiler has been specified in the Proposed Design
NA
Notes:
  1. Buildings of the listed occupancy types or spaces in Mixed-use Buildings with the listed occupancy types.
  2. Where attributes make a building eligible for more than one system type; use the predominant condition to determine the Standard Design system type provided the non-predominant conditions apply to less than 1,000 m2 of conditioned floor area. Use additional system type for non-predominant conditions if those conditions apply to more than 1,000 m2 of conditioned floor area. Use additional system type for any space which has a substantial difference in peak loads and/or operational hours compared to the predominant space type. Such spaces may include but are not limited to computer/server rooms, retail areas in residential, or office buildings.
  3. One AHU per floor at a minimum.
Table 9-3 Power Adjustment Factors for Automatic Lighting Controls
Automatic Control Device Daytime occupancy and area <300 m3 All Others
Programmable Timing Control 10% 0%
Occupancy Sensor 10% 10%
Occupancy Sensor and Programmable Timing Control 15% 10%

9.4.2 HVAC Systems

The HVAC system type and related performance parameters for the Standard Design shall be determined from Table 9-2 and the following rules:

  1. Other components: Components and parameters not listed in Table 9-2 or otherwise specifically addressed in this subsection shall be identical to those in the Proposed Design. Exception to §9.4.2(a): Where there are specific requirements in §5.2.2, the component efficiency in the Standard Design shall be adjusted to the lowest efficiency level allowed by the requirement for that component type.
  2. All HVAC and service water heating equipment in the Standard Design shall be modeled at the minimum efficiency levels, both part load and full load, in accordance with §5.2.2.
  3. Where efficiency ratings, such as EER and COP, include fan energy, the descriptor shall be broken down into its components so that supply fan energy can be modeled separately.
  4. Minimum outdoor air ventilation rates shall be the same for both the Standard Design and the Proposed Design except for conditions specified in §9.4.2.1.
  5. The equipment capacity for the standard design shall be based on sizing runs for each orientation and shall be oversized by 15% for cooling and 25% for heating, i.e., the ratio between the capacities determined by the sizing runs shall be 1.15 for cooling and 1.25 for heating.
  6. Unmet load hours for the Proposed Design shall not differ from unmet load hours for the Standard Design by more than 50 hours. Maximum number of unmet hours shall not exceed 300 for either case.

9.4.2.1 Minimum Outdoor air rates:

Minimum outdoor air rates shall be identical for both the Standard Design and Proposed Design, except

  1. when modeling demand controlled ventilation (DCV) in the Proposed Design (DCV is not required in the Standard Design as per §5.2.1.3)
  2. when the Proposed Design has a ventilation flow higher than the minimum required by the applicable code, the Standard Design shall be modeled as per the minimum ventilation rate required by the applicable code and the Proposed Design shall be modeled as per actual design (higher than Standard Design)

9.4.2.2 Fan Schedules

Supply and return fans shall operate continuously whenever the spaces are occupied and shall be cycled to meet heating and cooling loads during unoccupied hours.

9.4.2.3 Fan Power

  1. For Systems Types A, B and D,
    Pfan = cmh x .51
    Where Pfan = Standard Design fan power in watts
    cmh = Standard Design supply airflow rate auto-sized by the simulation software
  2. For System Type C Fan power shall be modeled as per power and efficiency limits specified in Table 5‑11 using a static pressure of 622 Pa or the design static pressure, whichever is higher. The simulation software shall automatically calculate the Standard Design fan power based on the above inputs.

9.4.2.4 Design Airflow Rates

Design airflow rates for the Standard Design shall be sized based on a supply air to room air temperature difference of 11 °C for cooling and 18°C for heating. The Proposed Design airflow rates shall be as per design.

9.4.2.5 Economizers (airside and waterside)

Airside economizers shall be modeled in the Standard Design as per the requirements of §5.3.5. Exception to §9.4.2.5: Airside economizer shall not be modeled for Standard Design HVAC System Type A.

9.4.2.6 Energy Recovery

Energy recovery shall be modeled in the Standard Design as per the requirements of §5.3.

9.4.2.7 Chilled Water Design Supply Temperatures

Chilled water design supply temperature shall be modeled at 6.7° C and return temperature at 13.3° C.

9.4.2.8 Chillers

Only electric chillers shall be modeled in the Standard Design for System C. Chillers shall meet the minimum efficiency requirements indicated in Table 5-1 and Table 5-2. Chillers in the Standard Design shall be selected as per Table 9-4 below:

Table 9-4 Types and Number of Chillers for Modeling Requirements for Calculating Proposed and Standard Design
Peak Building Cooling Load (kWr) Chiller Type
< 1,055 1 Water Cooled Screw Chiller
1,055 to 2,110 2 Water Cooled Screw Chillers equally sized
> 2,110 2 or more Water Cooled Centrifugal Chillers, equally sized such that no Chiller is greater than 2,813 kWr

Exception to §9.4.2.8: Air cooled chillers are allowed to be modeled in the Standard Design if the Proposed Design has air cooled chillers. If the proposed building has a mix of air and water cooled chillers, then the Standard Design shall be modeled with a mix of air and water cooled chillers in the same proportion as in the Proposed Design.

9.4.2.9 Chilled Water Pumps

Chilled and condenser water pumps for the Standard Design shall be modeled as per power and efficiency limits specified in Table 5-16. Standard Design chilled water pumps shall be modeled as primary-secondary with variable secondary flow.

9.4.2.10 Cooling Tower

Standard Design cooling tower shall be modeled as an open circuit axial flow tower with power and efficiency as per §5.3.3. The fans shall be modeled as two speed. Condenser water design supply temperature shall be 29.4°C or 5.6°C approach to wet bulb temperature, whichever is lower, with a design temperature rise of 5.6°C.

9.4.2.11 Boiler

Standard Design boilers shall be modeled as natural draft boilers and shall use the same fuel as the Proposed Design. Boiler efficiency shall be modeled as per Table 5-6.

9.4.2.12 Hot Water Design Supply Temperatures

Hot water design supply temperature shall be modeled at 82°C and return temperature at 54°C.

9.4.2.13 Hot Water Pumps

The Standard Design hot water pumps shall be modeled with a minimum efficiency of 70% and a pump power of 300 W/l-s-1. Standard Design hot water pumps shall be modeled as primary-secondary with variable secondary flow.

9.4.2.14 Campus/District Cooling Systems

All district cooling plants shall be assumed to be on grid electricity, unless otherwise specified and supported through pertinent documents. New district plants shall comply with the mandatory requirements of ECBC irrespective of who owns and/or operates the district plant.

Projects may choose either option A or option B given below for modelling campus/district cooling systems. Option A The cooling source shall be modeled as purchased chilled water in both the Standard Design and Proposed Design. For the Standard Design, Table 9-2, shall be modified as follows:

  1. For System Type C; purchased chilled water shall be modeled as the cooling source.
  2. System Types A and B shall be replaced with a two-pipe fan coil system with purchased chilled water as the cooling source.

The chilled water/thermal energy consumption simulated by the software shall be converted to units of kWh and added to the overall building energy consumption. The following conversion factors shall be used to convert chilled water/thermal energy consumption to units of kWh.
1 ton hour = 0.85 kWh
1 MBtu = 1,000,000 Btu = 293 kWh
Option B
The Standard Design shall be modeled as per Table 9-2. For the Proposed Design, model a virtual onsite chilled water plant with Chiller, Pumps and cooling towers modeled at minimum efficiency levels as per §9.4.2.7 to §9.4.2.10. Airside/low side capacities shall be modeled as per design and the plant capacities shall be auto-sized by the software.

9.4.3 Compliance Thresholds for ECBC compliant, ECBC+ and SuperECBC Buildings

For buildings to qualify as ECBC+ and SuperECBC Buildings, the WBP Method shall be followed for the Standard Design as detailed above. The Proposed Design for ECBC+ and SuperECBC Buildings shall meet the mandatory provisions of §4.2, §5.2, §6.2, and §7.2.

The EPI Ratio for ECBC+ and SuperECBC Buildings shall be equal to or less than the EPI Ratios listed under the applicable climate zone in Table 9-5 through Table 9-9 of §9.5.

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Energy Conservation building Code 2017

Conceptualized and Developed by Environmental Design Solutions Pvt. Ltd.

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