Taking resource saving to the next level with ‘Net Zero’ buildings

They match the energy they consume by producing power from renewable sources

Conserve water, recycle, save electricity, improve indoor air quality, reuse construction materials — as buildings grow and cities expand, these concepts are increasingly becoming a part of the routine.

Just over a decade-and-a-half back, ‘green buildings’ were a novel feature in urban development; today, these conservation measures are widespread. They are a part of the National Building Code and authorities offer incentives for adopting these resource-efficient measures. But is this enough? Not really. What next?

Some developers, who have made a mark in conservation and efficient use of resources, are going a step further to what is now called ‘Net Zero’ buildings.

Effectively, such buildings match the energy they consume by producing power from renewable sources. They do this by opting for wind or solar power which is generated onsite and offsite.

S Raghupathy, the Chair of World Green Building Council’s (WorldGBC) - Asia Pacific Network, says that in India there are half a dozen buildings targeting net zero status in energy consumption for now.

A couple of them, including Godrej & Boyce’s Plant 13 Annexe building, have gone beyond green building certification to achieve net zero status in energy consumption. The office-cum-convention centre of Godrej & Boyce at Vikhroli, Mumbai, was retrofitted and IGBC (Indian Green Building Council)-certified a couple of months back. It is an IGBC Platinum grade and BEE 5 Star rated building that is now also self-sustainable in power.

In the next few months, IGBC’s own headquarters in Hyderabad too will achieve net zero status, says Raghupathy.

But is this not a slow start? IGBC is a part of the World Green Building Council’s commitment to ensure that all new buildings will be net zero by 2030. By 2050, all buildings are expected to achieve power-neutral status. It may be slow, to start with, acknowledges Raghupathy, but the pace is bound to pick up. And he is confident that the targets are achievable.

His optimism is based on experience with the green building movement, with which he has been associated right from the beginning. Starting from scratch in 2003, there are now 5,325 green building projects, making for a 6.86 billion sq ft footprint in the country. India is among the top five in green built-up space.

Initially, the costs involved were 15 per cent higher than that of conventional buildings. Today, the incremental cost is just 1-2 per cent in the case of commercial buildings of more than 50,000 sq ft. The payback period is one year.

For individual homes it is about 5 per cent, with payback of less than two years. Raghupathy recalls that it took 8-10 years to break the cost barrier in green buildings. In net zero buildings, retrofitting adds 6-9 years to the payback period for now. But in 3-5 years, the payback will drop to 2-3 years and by 2022-23 it will be financially attractive for developers to go for the power-neutral status, he says. For new buildings the pay back is about seven years, with the additional cost pegged at 15-20 per cent more. In two-three years, it could come down to 7-8 per cent.

Creating favourable conditions

It is important that just as in the case of green buildings, net zero buildings are encouraged through voluntary compliance. As with green buildings, authorities in various States could consider giving incentives such as higher floor area ratio (FAR) and allowing more built-up space for a given plot area. Also, since net zero buildings will depend heavily on off-site power, utilities could consider favourable conditions for wheeling power. There are also ‘stumbling blocks’ for buildings that are entirely disconnected from grid power, he says. But this is an issue that needs to be addressed by the utilities and the State governments. Independent Power Producers and building owners are willing to participate in such arrangements for power. This could be facilitated, says Raghupathy.

Published on July 02, 2019

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