Indira Paryavaran Bhawan, the new address of India’s environment ministry, is India’s first net zero energy use office building, say the builders

Indira Paryavaran Bhawan in New Delhi is India’s first on-site net zero building. (Image by Central Public Works Department, Government of India)

It is impossible to enter Indira Paryavaran Bhawan and not be surprised. As one walks on the grounds of the latest environment-friendly building in New Delhi, an open courtyard leads to open walkways with ample sunlight and a pleasant breeze despite the oppressive summer. It’s a refreshing change from office buildings that are mostly enveloped in glass and lack open spaces.

Indira Paryavaran Bhawan is a flagship project of India’s Ministry of Environment, Forests and Climate Change. It will soon function as the ministry’s new office. Sprawled over 95,000 square metres and built at a cost of over Rs 200 crore ($33 million), it is the first multi-storeyed building in the country to attain net zero energy consumption.

Net zero buildings produce an equal amount of energy through renewable sources as they consume annually and thereby drastically reduce their carbon footprint.

At a time when 20% of the world’s carbon emission is attributed to energy-intensive corporate sector and with India being at a stage where 40% of its infrastructure is still to be developed, zero energy buildings are said to be the need of the hour.

“It is not only the greenest building in India but we can say that it is the greenest building in the world. We see many zero energy buildings but they are usually one storey or at the most two storeys. But this is the first time that a seven storeyed building has managed to generate power and on-site,” says Bhagat Singh, project manager of Indira Paryavaran Bhawan.

The building aims to generate 1.4 million KWh of energy annually through a rooftop solar PV system – sufficient to take care of its yearly energy demand.

But the installation of the solar infrastructure for a multi-storey building needed huge space, which was a major challenge.

“For seven storeys, we needed an area of 6,000 square metres to install solar. But only 2000 square metres were available. We managed to create the extra 4,000 square metres using a six-metre-wide cantilever all around the building,” says K.Y. Singh, assistant executive engineer, Central Public Works Department (CPWD). The CPWD was involved in the project management and execution.

“This is a breakthrough,” claims Bhagat Singh. “Otherwise, solar power generation would have taken place at another site which would have occupied additional space and there would have been distribution losses. So we have cut down on the energy there.”

The building saves 40% electricity and uses 55% less water than a conventional building of the same size. There are several eco-friendly features that have been installed in the complex to cut down on the energy usage:

• High quality solar panels with an efficiency of 20%have been used
• The ‘chilled beam’ air conditioning system that has been used increases energy savings by more than 50%
• Waste water is being recycled through sewage treatment plant
• A ‘robotic’ car parking system ensures each car uses 16 square metres less
• The building is oriented east-west to maximise cross-ventilation
• The air conditioning and heating systems use geothermal cooling, thus reducing water and electricity use further
• Double-glazed windows cut out more heat which in turn reduces the pressure on the air-conditioning system and saves electricity
• The complex has been landscaped to maximise rainwater harvesting

“We have taken care of the environment during construction as well. During construction, 11 trees were transplanted and saved. Plus, during basement construction around 6,000 tankers of water were extracted and given to the New Delhi Municipal Committee,” adds K.Y. Singh.

The building has got top green ratings – GRIHA 5-star and LEED India Platinum.

However, Avikal Somvanshi, Senior Research Associate, Centre for Science and Environment, says though Indira Paryavaran Bhawan is energy efficient, it is “not energy prudent”.

“The building uses the most energy efficient technologies to reduce the energy consumption of the mechanical systems but it doesn’t do enough to reduce its need for these mechanical systems. Hence the energy consumption is still high,” says Somvanshi. “If you compare it with the Haryana Renewable Energy Development Agency’s building in Panchkula that was designed to remain thermally comfortable without using AC, the agency’s building has an energy performance index (EPI) of 17 kwh/sq. m/annum while ministry’s building has a high EPI of 39 kwh/sq. m/annum.”

Keeping that in mind, the new office of India’s green ministry should still be able to serve as a model for upcoming buildings. But experts point to the challenges ahead.

“Going net zero in a building design requires two things – energy consumption reductions by design intervention and on-site energy generation to meet the remaining energy requirement. It is the cost of doing the second, on-site renewable, which is the major factor stopping uptake of such buildings,” says Somvanshi.

Further, in high-rise buildings, the roof-top space is too limited to install solar infrastructure to cater to the whole building and thus achieving net zero usually becomes difficult. Terraces are often used for other purposes as well like recreation or water heating systems. So blocking the area with solar panels is seen as a hindrance. The quality of solar panels is also a major factor. While the cost of solar panels has come down over the years, the cheaper ones often don’t perform to their full capacity. Moreover, huge investment is required for wiring and batteries to store the harvested solar energy which is not yet subsidized.

While there is still a long way to go before harnessing solar energy starts making both economic and spatial sense for buildings, Indira Paryavaran Bhawan has definitely sent out a strong message that challenges can be overcome.

“The building has avoided all the cost and complications related to batteries by adopting technology which feeds power it generates directly into the national power grid and then draws from the grid for its own needs, which is a great development, as this is happening for the first time and is one off case,” adds Somvanshi.

There are a few other well-known green buildings in India. The ITC Green Centre in Gurgaon near New Delhi – a sprawling 170,000 square feetoffice complex was the first corporate building to be certified as one. Its planners and users say the building saves them 51% energy and 40% water. Then there is the Akshay Urja Bhawanin Panchkula referred to by Somvanshi, which has a solar chimney, and energy efficient lighting everywhere. The newly-built office of the NGO Development Alternatives in New Delhi has a hybrid air-conditioning system that cuts down energy and water use by 40%.

But these examples are not leading to large-scale take-up by builders. Experts have estimated that two-thirds of the buildings needed in India in 2030 are yet to be built. That provides a major opportunity to move towards energy- and water-efficient buildings, but the process clearly needs a big push from policymakers.