Professor Brendan Nevin, a consultant on the scheme, is calling for a rethink. The Deputy Prime Minister has met huge criticism for his plan to flatten houses in the North and Midlands and build a smaller number of modern homes in their place. It costs about £100,000 to demolish and rebuild - four times as much as refurbishing existing properties. The plan has baffled many Londoners who see similar properties lovingly restored and fetching sky-high prices. It has added to controversy over plans to build thousands of new homes across the South-East.