Bombay House, Tata group´s headquarters in Mumbai, is India´s first heritage building to get the IGBC Gold rating.
The structure is a landmark, both for its architecture and the mega group it houses. Bombay House, the headquarters of the Tata group in Mumbai, was constructed in 1924. In 2009, an improvement programme was adopted for the building while change of cabling to make it fire-retardant was one of the initial ideas to ensure greater safety, the scope of the programme was extended to several initiatives in site and facility management, water efficiency, energy-efficiency, health and comfort and innovation. The result: Bombay House has become India´s first heritage building to get the Indian Green Building Council (IGBC) Gold rating under the IGBC Existing Buildings (Operations & Maintenance) rating system. ´Bombay House has been the headquarters of the Tatas ever since the time it was constructed,´ says FN Subedar, COO & Company Secretary, Tata Sons. ´We are very conscious of the character of this heritage structure and have been modernising it without giving up on its essential ethos and ambience.´ The initial idea was not to get green certification but to modernise the building with green features. ´At the back of our minds, we knew that there has to be a cost-saving and at the same time, if you are spending on something and it is the right thing to do, then it is worth the amount spent,´ he adds.
When the decision was taken to apply for IGBC Green Existing Building certification, there were a set of measures that were to be fine-tuned and implemented. That is when, eight to nine months ago, Ecofirst Services, a Tata enterprise, came into the picture and started looking into each and every aspect of the green building perspective. Site and facility management
Under the sustainable sites policy, there are some mandatory requirements. ´Bombay House does comply with all BMC bylaws,´ says Rakesh Bhatia, Vice President (MEP & Infrastructure Services) & LEED AP, Ecofirst Services.
Further, the solar reflective index (SRI) paint used on the roof complies with the credit requirements. To this, Chitranjan Kaushik, COO, Ecofirst Services, adds, ´This helps prevent heat gain into the building. It works as a reflector to the heat that comes from the sun.´
Also, there is a non-roof heat island effect, according to the site requirement, which is around the periphery. Eighty per cent of the building is surrounded by existing trees that are higher than the height of the building. However, Freddy P Talati, Chief Executive, The Associated Building Company, points out, ´If you look at the windows, these are glass windows and a lot of heat comes from outside. Hence, we plan to put a low-e film that reduces the heat by 60-70 per cent in coming months.´
From outside, the structure of Bombay House looks the same. However, as Talati recalls, ´In 2009, while selecting the equipment for power saving, we considered the cost to be invested as well as the return on value.´ So the first thing identified was the chiller plant and tube lights. LED tube lights, which save more than 50 per cent energy per tube light, were adopted. Also, a screw chiller plant with two compressors was installed, so if the temperature required is attained, only one compressor is used, leading to major power savings. Motion sensors were fixed in the cabins, which automatically switch off the lights when someone exits the rooms and switch them on when the room is occupied.
Bhatia further tells us about a few credit requirements that promote the use of green renewable energy in Bombay House. ´These are renewable energy certifications (RECs) purchased, which are equivalent to over 75 per cent of the annual electricity consumption requirement of the building.´ RECs, traded by Indian Energy Exchange, can be purchased and are valid for a period of three years where one can claim that the building is consuming green power. Here Kaushik simplifies, ´When I get power from BSES, I don´t know the source of it. But to ensure it is green, I am paying the difference to the market so the producer of the green power gives it to the grid.´
While RECs can be a costly option, Bhatia explains, the current market cost is at Rs 1,500 per MWh, which is at its lowest now.´ While it is easy to purchase RECs, for Talati, the next step is to find ways and means of installing solar panels and wind mills.
When Ecofirst Services was roped in, the consultants suggested some more measures on the water-saving front. However, there were a few challenges involved in this direction. The toilets were of heritage grit and the tiles were old. Also, the management was clear that none of the tiles should be broken. Based on this, a complete retrofit of the water utility system was carried out. Waterless urinals and taps with special washers that only allow 30 per cent of the water to flow in full capacity have been fitted. There was already an existing facility of water harvesting on the roof. All these initiatives together have helped achieve water savings of 40-50 per cent.
Improving air quality
Being a centrally air-conditioned building, the windows are rarely opened. This was another challenge; to introduce fresh air into the building. However, the air from the road level is not healthy. Hence, a decision was taken to draw fresh air from the top, the fourth floor, where complete ducting has been installed. Through the duct, fresh air is introduced in AHU rooms and office spaces to monitor and maintain a certain level of CO2 in air quality. Also, considering health and comfort, back in 1996-97, an ozone system was installed in the building´s air handling unit (AHU). This releases a certain level of ozone that does not allow fungus to form in the ventilation systems. Moreover, for air-conditioners, a temperature reader has been maintained in each office for 24o. Hence, the air-conditioner cannot be used until the temperature goes beyond the set degree.
The exemplary performance of any credit leads to innovation. Bhatia shares, ´So, if there is a credit requirement of 30 per cent water savings and we are achieving 50 per cent, here we get an exemplary performance innovation credit.´ Second, the group has also adopted measures to contribute to the common area by maintaining the neighbourhood.
Speaking of innovation in equipment, Talati reveals that new power-saving equipment has been installed in the panels where the capacitor can draw the exact amount of power it requires in the night, further saving power.
This, along with other features, has helped save electricity to the tune of about Rs 63 lakh per annum. With this, the company continues to increase awareness of building and maintaining green among its employees.
Maintenance and improvement
It is not just about maintenance, but improvement on a day-to-day basis. ´We have not received BEE´s 4-star rating but having fulfilled the requirement for the same, our target is 5-star in the next one year,´ says Talati. Here, Bhatia also believes that it is important for every stakeholder to be equally involved, including employees. Indeed, it is this complete engagement with the programme that has led to its success Bombay House achieved a green rating in five to six months, as against the regular 18 months.
Investments for retrofit: Rs. 3-4 crore.
RoI: 4.25 years.
contractor: Ashraay Enterprises.
Structural architect: Vikas Dilawari/
Green consultant: Ecofirst Services.
Tel: 022-6114 8181. Website: www.ecofirst.in
HVAC and electrical consultant: Inhouse - The Associated Building Company.
HVAC contractor: Voltas.
Tel: 022-6665 6666.
Lights: Phillips Electronics India.
Building management system: Honeywell Automation India.
Tel: 020-6603 9400.
Electrical contractor: Allied Techno Services.
Plumbing contractor: Burjor Framji & Co.
Roofing: Henna Enterprises.
Flooring/tiles: Johnson Tiles.
Paints: Asian Paints.
Tel: 022-3981 8000.