answer:1. In the US, these are public records held at the town hall / city hall. You could simply ask the seller (and then follow up by checking). (We also have Zillow.com in the US, which makes a lot of these records much more accessible. I don’t know if Zillow works in the UK yet or not.) 2. Do “comps”. Compare this house to similar (in the area) and base your offer on that, minus a bit for negotiating room. 3. I think I would use a buyer’s agent, simply because of my lack of experience, and the size of the investment. 4. SWAG: Scientific Wild-Ass Guess.