First, if a builder decides to increase the price of his house because his costs go up, that's what we call a consideration for the supply. But if by mistake a rate of 7% has been charged on a new house, where ownership and possession is transferred on or after July 1, there's always a rebate for tax paid in error. But now they have to prove that the tax was at 7% instead of at 6%.
On May 30th, 2006. See this statement in context.