buying house /selling present house

Hi

We are looking to buy a house which needs some work to it, asking price 700,000 looking to get it cheaper + 150,000 for renovations. The problem we have is :

Estate Agent - says he will only accept offer if it a clean purchase , i.e no house to sell

Bank : say they will not do bridging loan, and must put our house up for sale. We are reluctant to do this, in case we do not get this house, as not much on the market

Is anyone having these problems?

Gosh, just how rich are you??
Bridging finance is very expensive, it might take you up to a year to see your current house. How will you finance the new house if you don't sell the old one?