trading up - when to sell

We are considering buying a new house but it is not built yet. Have had our own house valued and happy enough with it. But if we buy the new house, will have to do deposits, stage payments etc. But whan is the time to put your own on the market so that it is sold in time for the new one to be ready? Also, do lenders let you draw down part of the new mortgage on the new house without paying off the old one (if you have sale agreed but not actually closed the sale) or would we have to look at bridging finance?

Kos, you'll need to consider how long it will take you to sell your current property - how quick it will sell and to what type of people (first time buyers or those trading up). You weren't clear if you are buying off a developer in an estate or if you will need to make stage payments to the builder. If the former, you might only need to come up with a booking deposit and a further deposit at contracts stage a few weeks later. The total amount here can be as low as 10,000 which you can probably raise. It could also be a lot more hefty. You should probably check this out. Personally, assuming your house will sell fast to a ready to go buyer, I would hold on as long as possible and speak to the bank about their different bridging options. The last thing you want is for the builder to be delayed by months and you have agreed to sell. You are in a good position assuming you have agreed the price of the new property. Sit back, let your current house appreciate and sell when your new property is nearing completion.

Your bank will probably agree that you can discontinue payments on your current loan if the need arises.
You mentioned stage payments. I did not think that builders can ask for stage payments anymore because You do not have to pay until you receive The Floor Area Cert and they do not send them out till the house is finished. They now look for a fifteen % deposit and have to wait for the rest till closing.