Green buildings are designed to be environmentally responsible throughout their entire life cycle. While energy efficiency is important, it is not the only factor that determines if a building is green. GRIHA evaluates buildings from a whole life perspective, considering energy use, materials, waste, and water management. It provides definitive standards for green buildings and rates their overall performance, not just energy efficiency. Regular monitoring during construction and operation is needed to ensure buildings meet their intended green performance.
2. Life Cycle Perspective
Material acquisition
Manufacturing
Construction
Operation
Reuse/recycle
deconstruction
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
4. 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
5. 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.
6. 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.
7. 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.
8. • 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.
9. • 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.
10. 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.
11. • 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.
12. 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.
13. 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.