Energy Conservation Building Code (ECBC)

The Energy Conservation Building Code (ECBC), launched on 28 June 2007, is a document that specifies the energy performance requirements for all commercial buildings that are to be constructed in India. The code is mandatory for commercial buildings or building complexes that have a connected load of 500 kW or greater or a contract demand of 600 KVA or greater. The code is also applicable to all buildings with a conditioned floor area of 1,000 m2 (10,000 ft2) or greater.The ECBC has been developed by India’s Bureau of Energy Efficiency, and is mandated by the Energy Conservation Act, 2001, passed by the Indian Parliament in September 2001.

ECBC is a set minimum energy efficiency standards for design and construction. ECBC encourage energy efficient design or retrofit of buildings so that it does not constrain the building function, comfort, health, or the productivity of the occupants and also have appropriate regard for economic considerations (life cycle costs i.e. construction + energy costs are minimized).

BEE would take suitable steps to prescribe guidelines for energy conservation building codes. Central Government can prescribe energy conservation building codes, and direct owners/occupiers to comply with them. State Government can modify the code in response to local climate conditions. ECBC provides a platform for the Broad stakeholders such as Building Industry, manufactures, professionals, Government Agencies etc to participate. ECBC addresses local design conditions and construction practices. It also emphasis on maximizing building envelope benefits – to encourage better designs.

ECBC defines the norms of energy requirement per sq. metre of area and takes into consideration the climatic region of the country, where the building is located. Norms have been developed to cater to 5 different climatic zones in India such as composite, hot and dry, warm and humid, moderate and cold.

The ECBC provides design norms for:

• Building envelope, including thermal performance requirements for walls, roofs, and windows, except for unconditioned storage spaces or warehouses.


• Lighting system (Interior and exterior lighting), including day lighting, and lamps and luminaries performance requirements.


• Mechanical systems and equipment, including ventilating, and air Conditioning.


• HVAC system, including energy performance of chillers and air distribution systems.


• Electrical system and motors.


• Water heating and pumping systems, including requirements for solar hot-water systems.

The code provides three options for compliance:

1. Compliance with the performance requirements for each subsystem and system;


2. Compliance with the performance requirements of each system, but with tradeoffs between subsystems; and


3. Building-level performance compliance.

Simulation exercises indicate that ECBC-compliant buildings use 40 to 60% less energy than similar baseline buildings.

ECBC development Process

1. An extensive data collection was carried out for construction types and materials, glass types, insulation materials, lighting and HVAC equipment


2. Base case simulation models were developed


3. The stringency analysis was done through detailed energy and life cycle cost analysis.


4. A stringency level for each code component was established


5. Code was finalized after consideration of comments on a draft version.

ECBC Scope

1. Mandatory Scope Covers commercial buildings


2. Applies to New Construction only


3. Building components included
   
   
   
   • Lighting (Indoor and Outdoor)
   
   
   • Building Envelope (Walls, Roofs, Windows)
   
   
   • Heating Ventilation and Air Conditioning (HVAC) System
   
   
   • Solar Water Heating and Pumping
   
   
   • Electrical Systems (Power Factor, Transformers)

ECBC Compliance Approaches

1. Component-based (prescriptive)

• Requires little energy expertise


• Provides minimum performance requirements


• No flexibility

2. System-based (trade-off)

• Allows some flexibility through the balance of some high efficiency components with other lower efficiency components

3. Whole building design analysis (performance)

• Allows flexibility in meeting or exceeding energy efficiency requirements (as compared to a baseline building)

Building Envelope Design

Impact of Energy Codes

1. Market Development for EE products

• Building Insulation


• Energy Efficient Windows (Glass and Frames)


• High-Efficiency HVAC Equipment

2. Improved Design Practices

• Lighting and Day-lighting


• Natural Ventilation/Free-Cooling Systems

3. Lower Energy Use and Reduced Electricity Bills

4. Reduced connected load and Improved Power Factor

GRIHA: Necessity, Not Luxury

For those in the know, an introduction would be redundant. But for those who aren’t, an introduction is a must – An introduction to GRIHA, or Green Rating for Integrated Habitat Assessment. It is, essentially,

• A point based voluntary scoring system to evaluate commercial, residential and institutional buildings on "green scale"


• Is based on Indian codes, standards and best practices


• Comprises an evaluation panel of eminent professionals
  

All right, so what’s the news? The news is that the Union Government of India has, in a landmark decision, made it mandatory for all new buildings of the Public Sector Undertakings and the government to seek new green rating norms in an effort to ensure energy efficiency and tackle climate change threats. Every government building, the law says, must get at least 3-star rating (on a scale of 1-5 stars) under the GRIHA scheme. And why not? The idea is to minimise demand for non-renewable resources and maximise utilization.

Take, for example, the Earth System & Environment Science Engineering Building, a research facility located in the Indian Institute of Technology Campus, Kanpur. The facility, as the name suggests, houses laboratories and other facilities for various disciplines of the environment sciences. The facility is nestled into the existing landscape. In siting the building, the natural course was left undisturbed. The architecture of the building has been designed around the existing vegetation, so as to not disturb the natural surroundings and fully grown.

The facility houses wet labs which are non-air-conditioned spaces on the ground floor and dry labs that are air-conditioned spaces on the first floor. Building design and envelope has been optimised through selection of appropriate wall and roof construction and through adoption of passive design measures after studying the sun path analysis to provide shading devices for windows and roof which would reduce energy demand to condition the spaces. This is probably the only existing building in India with a GRIHA rating of 5 stars, though there are several similar proposed projects, such as the Triburg Headquarters at Udyog Vihar in Gurgaon, Integrated Township in Kanyapur, Asansol, West Bengal, and the Office of Public Works Department, Nashik

Today, glass has an almost indispensable role to play in green architecture. Energy efficient glass is the need of the hour, given its unmatched features of optimum transparency that helps in day lighting of interiors, solar control & thermal insulation which cuts down the relative heat gain, and so on. To elaborate, glass can do the following wonders:

Day Lighting - The use of glass allows the penetration of adequate daylight and facilitates a reduction in power consumption.

Energy Efficiency - High performance glass helps control solar and thermal heat gain, thereby cutting down on air-conditioning expenses.

Recyclability – All architectural glass products are recyclable and qualify as “green” building material.

Recycled Content – The production of glass requires a minimum level of ‘cullet’ or broken glass in the Float Glass manufacturing process thereby by qualifying it as a material with high recycled content.

Acoustic Control – Certain types of architectural glass provide a high degree of acoustic comfort by obstructing the entry of sound from the exteriors of a building.

Blending Interiors with Exteriors – Facades made with reflective glass do not obstruct visibility from the inside.

Self Cleaning – The future belongs to environment friendly self-cleaning glass, a type of architectural glass that keeps itself clean and imparts a brilliant aesthetic effect to buildings.

Green architecture – GRIHA becoming law – Glass. Not just alliteration. A symphony, a necessity, a calling.