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