vijay srirangan has invested half a million dollars in an apartment in this building complex in a mumbai suburb. even though it won't be ready till 2013. >>srirangan: they've got gardens, specialized gardens planned. they've got the usual clubhouse; they've got tennis courts that are planned, other games facilities are in place, children's park. several of those features, the ability to walk around inside the complex - as you grow older that's an important element - all of these add up to making this premium, exciting, and worth spending on as far as i'm concerned. >>reporter: the world's tallest residential tower, world one is planned in central mumbai. 60 percent of its apartments have already been sold, with prices up to 17 million dollars. when completed in 2014, the building will soar 450 metres above the arabian sea, but it's not just status that's driving the reachupwards.... >>lodha: at that height the theoretical temperature drop is 5 degrees from the ground level; so the air up there is 5 degrees cooler than it is at the ground. >>reporter: this is just one of a new wave of sup