We're looking at a three bedroom Victorian house to buy in London. It's
in a street near were we live now, and I know that some of the houses
on that street have had some (fairly minor) subsidence, involving the
bay windows cracking away from the main structure.

When we looked at the house I mentioned this to the vendors and they
said that they've had no trouble, although they've only been there for
three years. The agents say that it's all clear as well. Before we
cough up for a full-structural survey and solicitors, I'm wondering
whether I can find out any more myself. If I ask for quotes from
insurance companies will they be able to chack some database and say
whether there's ever been a claim against that address (even if they
don't insure it)? I know this seems a bit sneaky, but I'd rather allay
my own fears than find out after I've paid a surveyor, and I don't
think there's anything illegal about getting a quote for someone else's
house.