Americans who come to the UK knowing that they plan to stay for a while often look to buy a property there, depending on such factors at the time as interest rates and the strength of the U.S. dollar relative to the British pound. Owning rather than renting doesn't always make financial sense, but when done correctly it often does, and there have been times when it's paid off extremely well for such U.S. expats when the time came for them to sell.