Green Buildings Matter- Do them correctly!

Performance of a Rated Building

Life Cycle Perspective

Material acquisitionManufacturingConstruction

OperationReuse/recycledeconstruction

Green buildings are environmentally responsible through their life cycle- design, construction, and operation & after deconstruction.Energy efficiency, though a significant aspect of any green building, is not the only determining factor of a green building

GRIHA Strategies

Energy Efficiency

GRIHA

Site Development

Solid Waste

Management

Water & Waste Management

Materials

GRIHA evaluates environmental performance from a whole building perspective over a building’s life cycle, providing a definitive standard for what constitutes a ‘green building’.

Energy performance index (EPI) is total energy consumed in a building over a year divided by total built up area in kWh/sq m/year and is considered as the simplest and most relevant indicator for qualifying a building as energy efficient or not.The Star rating program of the Bureau of Energy Efficiency rates a building based on its EPI and thus, energy efficiency only.While a green building rating system such as GRIHA rates a building on many indicators in the holistic definition of green buildings.

Building Energy Efficiency

What is GRIHA

• A rating system that was developed by TERI and MNRE to provide a guiding and performance oriented system where points are earned for meeting the design and performance intent of the criteria.

• Promotes integrated, whole-building design practices.

• It is developed based on Indian needs.

Why was GRIHA created?

GRIHA was created to:• quantify aspects such as energy consumption,

waste generation, etc., to manage, control and optimise the same to the best possible extent.

• promote integrated whole-building design practices.

• raise awareness about green building benefits.• transform the building market.

To ensure that all commitments are made on paper are implemented on site, GRIHA’s team conducts three handholding site visits.

The first principle of a green building is proper design and installation of the building systems.

• Performance of a building through its life depends on its operation and maintenance.

• The building needs to be operated as designed to perform as intended.

• For example, if the user of a building (which incorporates day lighting) uses artificial lights, the desired savings will not be achieved.

• Performance monitoring is a key strength and differentiation for GRIHA.

• No building is given final rating, till it performs to be efficient and effective.

• To support this policy, TERI recently conducted a study of energy performance of a few GRIHA rated buildings.

Case Study: Fortis Hospital, Shalimar Bagh

• It is a 3 star GRIHA rated building.• It has an operating energy performance of

157 kwh/m 2/year (HVAC & lighting energy).• It is significantly better than its initially

calculated energy performance.• Energy performance (EPI) of a building gets

calculated using a special software for energy stimulation.

• The assumptions on equipment efficiency, occupancy, weather and several other parameters determine the predicted/calculated energy performance.

• The actual energy performance , when the building starts functioning, may have significant variation from the simulated performance due to climate variability, actual occupancy, operating efficiency of equipment, hours of operation, etc.

• It is very important that measured data is critically evaluated to ensure that the building is performing as intended.

• GRIHA has embraced this within its system and, proving performance of a provisionally rated building is the only way to get final rating under GRIHA.

Understanding of EPI

• EPI varies significantly with varying number of people, internal loads, percentage of air-conditioned space, surface to volume ratios and various other parameters.

• The TERI-GRIHA 2 star rated corporate headquarters of a multinational company in Mumbai has been analyzed for giving a sense of the variation.

• The current EPI of the building as determined under GRIHA is 120 kWh/m 2/annum . The building has an occupant density of 37m 2/person and equipment power density (EPD)8.8W/m 2.

• if the building was densely occupied say to be occupied @ 8m 2/person and had an EPD of 25W/m 2 the consumption would have been 140 kWh/m 2/annum, about 15% higher than present level.

• Thus, EPI has to be contextualized and put in right perspective.

Conclusion

• Energy performance index, that is determined by total energy consumed upon total built up area should be understood in the right context and is not the only determinant of a green building.

• Operation and maintenance is critical for maintaining “greenness”.

• Buildings undergoing green rating should be monitored through construction and operation.

• All green parameters should be monitored and performance should be judged based on holistic performance.

• Large construction projects undergoing environmental clearance are required to incorporate most of the green/sustainability parameters as required by green building rating systems.

THANK YOU