Biodiversity Conservation India Limited (bcil), which was set up in Bangalore in 1995 by Chandrashekar Hariharan, is known for its eco-friendly sustainable homes like tzed and TownsEnd. The company has its roots in the ngo background of its promoters who, for many years, worked on basic resources of water and energy with the Academy for Mountain Environics. Says chief executive officer Hariharan: "We wanted to take these values to the market place in such a way that people were willing to pay a price for them. Our aim is to offer homes that hark backto a traditional past, while respecting contemporary engineering." bcil, which calls itself a 'builder-technology' enterprise, builds homes that reduce the burden on municipal services by harvesting water, reusing waste and tapping solar energy. Its first project Trans Indus' comprised 58 independent homes spread over 47 acres in Kanakapura Road. Since then, bcil has built both independent homes as well as apartments, bcil's latest projects in North Bangalore include an apartment complex called bcil collective and Red Earth, which will have around 340 independent homes. Commenting on Collective, which is spread over three acres, Hariharan says: "While the industry norm is 65-90 homes per acre, at Collective we are offering 38 homes per acre. This reduces the pressure on the land for water." Another factor that differentiates bcil is its choice of building materials, bcil does not use bricks, clay blocks or tiles or any concrete blocks of conventional kind, because all these use high energy in their manufacturing process. Instead, bcil works with laterite and soil-stabilised blocks stones, which help in reducing heat gain and resulted in cooler homes. It also uses natural stones and non-toxic paints. Roads in all the bcil projects are soft roads and their surfaces are permeable, as they use perforated tiles interspersed with vegetation. Tertiary sewage treatment plants filter and reuse waste water. Says Hariharan: "We need to be aware that a building is not just a building. It is in fact an energy system and we are constantly working to reduce the energy that a building needs." bcil homes are priced Rs45 lakh to Rsl .5 crore.