Green building norms: In need of a big push in Bengaluru

Structures built by mass-produced materials that create uniform-looking glass and steel facades unrelated to the region must be replaced by sustainable materials and methods to reduce the city's carbon emission, feel experts.

A recent study by S Manasi and Channamma Kambara, faculty at the Institute for Social and Economic Change (ISEC) showed that residents of Bengaluru were well aware of green building practices, but cost prevented many of them from going for it. The study suggested policy interventions to promote sustainable construction of homes and offices.

What is a green building or construction? Sustainable buildings have demonstrated reduced energy and water consumption and completely eliminate construction and operational waste through recycling. As opposed to this, research says modern buildings are estimated to consume 25 to 30% of total energy and up to 30 % of fresh water. They generate approximately 40% of total waste.

Bengaluru has grown from under 220 sqkm to 8,000 sqkm and beyond, with the built environment in the city increasing every day, adding concrete while reducing green cover. Temperature rise and heat islands are the natural effects of increased urbanisation.

“Bengaluru has morphed from a garden city to a realm of chaos and anxiety. Along with lifestyle choices of the 21st century and overconsumption, built practices and pressure from real estate also contributed to it,” says Yashaswini Sharma, a city-based architect.

“Today's built practice is influenced by mass-produced materials, which create characterless glass and steel facades unrelated to the region and its history, straining the city's depleting resources and infrastructure,” she adds.

“Traditional built practices were sustainable and organic. As a result, the spaces had regulated temperatures, which remained cool in summer and resulted in buildings that stood the treat of time for over a century. It was also a closed loop system which didn't add construction debris to landfill,” adds Yashaswini.

‘Lack of skilled labour driving prices up’

“We went from lime-based, mud-based construction to cement-based construction. Cement as a commodity has become competitive, so prices of conventional structures have reduced,” says Deepak V Punam, a PhD scholar at ISEC and a construction professional, explaining why the cost of constructing green buildings is often higher than conventional ones.

“Conventional and sustainable buildings have a 25-30% price difference. We do not find people skilled in following the old lime-based construction methods. Today's labour force is unskilled, and it is one of the factors pushing costs up,” he adds.

“Sustainable concepts are artistic, and skill is a requirement. In green buildings, we do not do plastering. Anomalies in solid blocks can be rectified by plastering, painting, etc., but not in sustainable buildings,” says Deepak, adding that efforts to train labourers do not work out due to the unorganised nature of the sector and adamant mindsets.

“The new generation has to venture into this using it as a business opportunity; only then can we see better days,” says Deepak.

Leaving a low carbon footprint

“Some builders stick brick cladding to give solid block walls an earthy, rustic look. This cannot be called a green building. A green building has documented proof of carbon emission reduction in the construction and maintenance phases,” he adds.

Everything used in construction, be it cement, mud or wood, leaves a carbon footprint in production and transport logistics. For example, using imported teak for doors is a high-carbon footprint affair due to ship-based transport, time and energy, while procuring local teak reduces carbon footprint as its transport takes less time and energy. Similarly, using local granite stones helps reduce the footprint further.

“People go for imported high-carbon footprint items for prestige and beauty without being conscious of the environment. Unnecessary lighting, placing granites on walls, etc., are the practices that make buildings non-green,” says Deepak.

He explains that construction and demolition (C&D) waste can be reused while building new buildings. “Any non-load-bearing structure and flooring in a building can use C&D waste aggregates. In regular concrete, C&D waste can be used upto 30%, resulting in the same strength. If it is strong enough, wood can be reused by polishing it. But today, people do not reuse wood due to superstitions,” he rues.

IGBC rating: Bengaluru stands 5th

The building and construction sector is a major contributor to global warming, with:

» 25 – 40% of global energy consumption

» 30 – 40% of solid waste generation

» 30 – 40% of global greenhouse gas emissions

Ratings and certifications are tools to evaluate performance in terms of energy efficiency, water use, etc., as tangible benefits. Each rating caters to a different building type, and the guidelines differ to address the best suitable green features and implementations.

Indian Green Building Code (IGBC) instituted by the Confederation of Indian Industries (CII) is one of the green building rating systems that dominates the market. It has guidelines for net-zero water, waste, energy and carbon buildings and 31 rating systems to address almost all sectors —residential, commercial, transit, built environment, logistics, data centres etc.

Bengaluru has around 723 projects of various kinds with green ratings by the IGBC, covering around 806.14 million sqft of built environment. About 252 projects measuring 117.37 million sqft are already certified.

What does this figure mean to the city? Can the city improve further? “Yes, there are lots of opportunities. Hardly 5-6% of the built environment is currently being developed with green compliance and achieves certification,” says Sidhesh Kumar Mishra, Executive Officer, CII-IGBC, who also looks after the Bengaluru market.

Bengaluru is among the top five cities in IGBC's list of green compliance. With suitable government policies and incentives for green buildings, it could achieve the top position easily within a very short period, feel IGBC officials.

The interest in getting green ratings among Bengaluru-based corporates is very good. “They are driving the movement,” says Mishra. “However, it is not enough. It is necessary to encourage other players, developers, etc., to get green ratings,” he adds.

What should the government do?

Bruhat Bengaluru Mahanagara Palike’s building bylaw guidelines (2017) mention provisions for green buildings and sustainability, some mandatory and others optional. The mandatory provisions apply to new and existing buildings. Waste segregation, organic waste management, construction and demolition waste management, energy efficiency measures, solar installations, rainwater harvesting and wastewater treatment measures have been made mandatory, depending on the plot size and building size.

Optional guidelines aim to achieve better green ratings for the new and existing buildings. People and businesses aiming for green building ratings can incorporate the additional provisions to avail government incentives. These include provision for greening measures, such as compensatory afforestation and having at least one tree in every 80 sqm of land, leaving more than 20% of the open spaces unpaved, wastewater reuse, solar water heaters and energy systems, zero waste systems, etc.

The optional provisions advocate the use of sustainable building materials such as factory-made prefab/precast and recycled components with green benefits, panels, hollow slabs, hollow blocks, fly ash bricks, fly ash concrete, gypsum-based walling and roofing panels, particle wood, use of bamboo and rapidly growing plantation timbers and local materials etc.

This aims to conserve materials and water, reuse industrial/agricultural byproducts, reduce air conditioning requirements, environmental benefits, low transportation costs and time, and reduce carbon footprint.

However, since these guidelines are optional, the Karnataka government is said to be ready with a state policy for green buildings but has yet to sign off on it.

“The government should bring out the green credit market and tax rebates to motivate people to go green buildings. This is lacking right now. Solar is a hit today due to subsidies and incentives. Similarly, the government should encourage other green practices,” says Deepak.

“The government has yet to frame a directive for sustainable building practices. Currently, LEED certification defines what material is green and what is not. It's not so much about the end product but about the process. There is still a long way to go,” says Yashaswini.

Mishra thinks government incentives can help more constructions go green. “Around 12 Indian states have already encouraged green building construction, in terms of incentives such as additional floor area ratio and rebate in property tax,” he says, adding that the Karnataka government should also head in the same direction.