Energy efficiency, sustainability key to future buildings

Bengaluru: Even in Bengaluru, the city known for its milder weather, summer heat is getting fiercer.

In 2011, according to the Indian Meteorological Department, the highest temperature recorded in April was 34.6 degrees Celsius. This year, for the last three days, the maximum temperature was recorded at 36 degrees. Some weather websites predict that on April 25, it is likely to touch 37 degrees Celsius.

Although a myriad of reasons contributes to the increasingly intense summers, the construction sector is identified as one of the bigger culprits of global warming.

"Given the increasing pressure brought by recent global environmental problems, not only sustainable practices that aim at reducing pressure on earth's resources, but also energy efficiency have become the key for buildings now. Some architects are even looking towards traditional structures for inspiration," said R Shanthi Priya, professor at School of Architecture and Interior Design in Kattankulathur, near Chennai.

Understanding the need of the hour, Priya does extensive studies on climate responsive design principles of the vernacular architecture, particularly that of Dravidian temples, Toda huts of Nilgris, traditional buildings in Nagapattinam and Chettinad houses. Anupa Kurian, a Kochi-based architect, who recently renovated her 100-year-old ancestral house in Kottyam, agrees that there is a lot that one can learn from traditional structures. "The form and function went hand in hand. Sloped roofs were the norm in rain-prone regions. In Kerala, which gets unbearably humid too, much attention was given to air flow – the ‘mukkapu’ in the attic was not just to make the house look majestic, it circulated air and kept the house cool." But for Siddharth Achaya, senior architect at Bengaluru-based Biome Environmental Solutions, inferring from traditional buildings should not be at the cost of newer solutions. "Yes, from climate perspective, certain traditional forms – like roof styles or high ceilings – make sense. But often, when done the wrong way or at the wrong place, whatever gained is also lost." Sustainable building practices, said Achaya, do not have to rely only on vernacular architecture.

"We take care to use lower embodied energy materials wherever possible – that is, reduce the use of cement and steel. Yes, where we can, we use compressed stabilised earth blocks (CSEBs), but they are not exactly traditional. They are machine compressed to improve speed and quality of the blocks. They also contain a small percentage of stabiliser in them – mostly lime and cement – to increase the strength and durability of the walls," added Achaya.

Locally available materials, skill sets and ideas derived from traditional buildings are how architects Chaitra Saraf and Nidhish Kurup shape their sustainable buildings. But they said to get the most out of these, cutting-edge technology is needed.

The energy-efficient hotel built by their firm Design Kacheri in Chikkamagaluru in Karnataka, Sunyata, is a perfect example of how technology can lift age-old practices. The building has embodied many advantages that the vernacular architecture of the region offers, but look nothing like the Malnad houses.

For instance, to work around the disadvantages of building load-bearing structure, which reduces the use of cement considerably, the architects have leaned heavily on vernacular architecture, but have boldly taken it out of context. Normally, load-bearing structures would mean smaller windows and other openings. But the combination of brick jaalis, courtyards, mutual shading techniques, brick vaults and jack arch roofs have opened up the place to even more light. The architects also point out how passive cooling is achieved by incorporating a combination of solar chimneys and earth air tunnels connected to cool air shafts that open into each room inducing passive ventilation, thus avoiding air conditioning in all spaces. "Both the concepts are very old, but they have not been adapted to modern times," said Kurup. "The massive underwater tank, which stores 50,000 litres of rain water and makes it possible for the hotel to run on just this alone for almost seven months, and the bacterial-based on-site sewage treatment plant that works on gravity are not new concepts again, but the approach is new. And technology made it possible to adapt them," said Saraf.

The duo believes that newer technology – like even the 3D printing, which at the moment uses primarily cement, a higher embodied energy material – could be used to bring the best out of traditional techniques.

"Even at its infancy, 3D printing construction offers an edge over conventional construction. It offers almost zero waste and, therefore, a significant reduction in carbon footprint. Also, projects can be completed on time. And with time and research, cement can be replaced with even mud," said Amit Ghule, chief operating officer of Simpliforge Creations. The startup along with Indian Institute of Technology Hyderabad had recently printed a prototype bridge, first in India, using indigenous 3D printing technology. Excited by the architectural freedom such a technology offers, both Saraf and Kurup are already toying with what eco-friendly options can be used instead of cement. “I think filler material made of construction debris could be a win-win in future,” said Saraf.