Gareth wrote:

Is it possible to take out an insurance policy which will refund costs
(e.g. survey and conveyancing costs) in the event of a house purchase
falling though?

It's pretty unnecessary.

1) You don't need to pay for a survey because the seller has already had
one carried out on your behalf. It all in the fancy newfangled HIP. :-)

2) If the sale falls through, no conveyance has occurred, so there should
be no conveyancing costs.

3) There are only two basic reasons why a sale falls through. Either the
buyer doesn't want to go ahead, or the seller doesn't. Obviously the
former would be under your control, so it would be impossible to insure
against that. The best way to ensure the latter doesn't happen is to
make the contract binding at an early stage. That way you can sue the
seller if they pull out.