Last August (2007) we had a 10k refundable deposit down for a new build in the south east. The price as 320 for a detached 4 bed. When we told the builder we no longer qualified for the full mortgage amount, we were asked what the bank WOULD lend and that we could come to some sort of arrangement. Seeing as that was a year ago before things really went "south" I would expect a lot more from the builder these days in terms of flexibility. As long as your deposit is refundable, just say you are pulling out and request return of your deposit. I think the builder would change his tune very quickly. And if not, there are lots of new houses in schemes in the south east standing empty that would be happy for your attention!