The Indian company that launched the world's cheapest car has unveiled its latest product for the fast-growing nation: a flat-pack house that costs just $700 and can be built in a week. The Tata group, maker of the $2,500 Nano car, said that the 20-square-metre (215-square-foot) home comes from a pre-fabricated kit that includes doors, windows and a roof. "We have already prepared two-three different designs based on discussions with users and are gathering more feedback," Sumitesh Das, the head of the project at Tata, told reporters in Hyderabad. "Hopefully, in the next six-eight months we should be able to roll it out in the market nationally." The basic model of a so-called "Nano" house will cost 32,000 rupees ($720) and will use coconut fibre or jute for wall cladding and interiors. It has a life expectancy of 20 years.