Indian Green Building Council (IGBC) of CII, with the support of all stakeholders, is spearheading the green building movement in India since 2001. As part of its activities and initiatives, IGBC has launched seven green building rating systems to suit various building types, including a rating system for greening existing buildings. The objective is to address national issues like water conservation, energy conservation, reduction in fossil fuel use for commuting, handling of waste and conserving natural resources. Most importantly, these concepts can enhance occupant health, happiness and wellness.

IGBC Green Existing Buildings O&M rating system has paved way for existing building stock to go the green way. Within

just a few week of the launch of the rating system, over 15 projects amounting to over 2.15 million sqft have already registered with IGBC. Bombay House, the headquarters of the Tata Group in Mumbai, has earned the unique distinction of becoming India’s first IGBC Gold rated existing building. IBIS Hotel in Navi Mumbai is the second such existing building. We feature the highlights of these two pioneers.

Bombay House: Bombay House has been the seat of senior management of the Tata Group ever since its establishment. Some of the benchmark sustainability practices recently introduced at Bombay House, and recognized by IGBC, are as follows:

A Green Policy has been introduced for all Tata Group’s future building retrofits and renovation.

Evaluating as per the Bureau of Energy Efficiency (BEE) Star Rating Index, the building has achieved a 4-Star Energy Saving Rating by saving energy in excess of 20%. Bombay House, for the whole of 2013, has achieved an Energy Performance Index (EPI) of 124.96 kWh/ m2/year. Efforts are on to further bring down the EPI below 100 kWh/m2/year.

To promote the use of green renewable energy in Bombay House, Renewable Energy Certificates (REC) equivalent to more than 75% of the annual electricity consumption requirement of the building have been purchased.

The building has achieved water saving of more than 50% by implementing measures like rain water harvesting, ultralow flow fixtures and dual flushing system.

Demand control ventilation, through CO2 sensor-based fresh air intake, has been installed. This regulates fresh air quality inside the building, thereby ensuring peak productivity and wellness of employees. Special elevators have been installed for the physically challenged.

Use of Car Pools and Public Transport

More than 75% of the occupants of the building use car pools and/ or public transport.

Beyond the Fence Initiative

The Group has also adopted measures to contribute to the maintenance of the common area in the neighbourhood

of Bombay House. This includes the ESSO Park with eco-friendly landscape practices, and Horniman Circle Park.

Ibis Hotel, Navi Mumbai: Ibis is an international budget hotel chain owned by Accor Group of Hotels. It is amongst India’s most efficient branded budget hotels from the space planning perspective. Some of the key green features of the hotel are:

1. The hotel has incorporated energy efficient air cooled VRV system.

2. The air conditioning systems are monitored and controlled through a Central Remote Control System which logs into IBIS world-wide control and monitoring.

3. Separate metering is provided for lighting, air conditioning, mechanical parking and fire fighting.

4. Sensors are provided for CO level based mechanical ventilation system for basement car parking.

5. There is a good amount of daylighting throughout the guest rooms and common areas, through judicious placement and sizing of glazing.

6. The landscape in the building periphery includes native species and uses only organic fertilizers.

7. Part of the roof terrace has a solar hot water heating system to produce hot water. The remaining part of terrace has white china mosaic tiles, laid in zigzag pattern, to provide high solar radiation reflection index (SRR) and minimize air conditioning load as well as energy consumption.

8. There are two mediums of hot water heating – solar water heating on the terrace and mechanical hot water system in the basement.

9. Water treated at sewage water treatment plant is used for landscaping.

10. Water and energy readings are regularly monitored through IBMS.

11. Waste generated is collected and segregated appropriately.

12. Parking space has been provided for the physically challenged.

Conclusion: If all the existing buildings in India can enhance their energy effi ciency, conserve water resources, improve the indoor air quality, and eliminate waste, it will vastly improve the wellness and living style of the occupants, thereby resulting in significant national benefi ts. The energy and water saved can be diverted to other deficit areas. Greening of existing buildings also offers immense untapped market opportunities. It is estimated that by 2025, the retrofit potential of existing buildings in India, would be about USD 25 billion. Therefore, going the IGBC Green Existing Building way is not only good for planet earth but also for the national economy.