Continuity mistake: In the fight scene in the library, Chon throws a small book at the guard. When the guard cuts it using his sword, the pages that were/are in it are big and white.
Continuity mistake: Towards the middle of the movie Wilson is sitting down with some wine beside him on the table talking to Chan. In the first shot the glass is almost full, in the next shot it is nearly empty and has moved, and in the next shot it is once again almost full.
Continuity mistake: Charlie pours Owen Wilson a drink from a crystal jar. When Charlie puts the jar down, the liquid inside is shaking rather violently behind Roy. It cuts to Jackie Chan at this point, but when it cuts back to Owen, the liquid is perfectly still in the jar.
Continuity mistake: In the library fight scene, Chon (Jackie Chan) is on the ladder and kicks the books on one of the shelves and the shelves collapse. But in the next shot, all the books are gone whereas they should still be there. (00:50:20)
Continuity mistake: In the battle in the English market, in one shot Jackie Chan rolls over a bunch of lemons. The only problem is that a few shots earlier, there was a bunch of baskets over the lemons that apparently disappeared.
Continuity mistake: When Jackie's sword gets thrown into the gears of Big-Ben, the way it lands doesn't match the way it falls.
Continuity mistake: When Owen Wilson threw the British people the diamond, and they caught it, the red string was on the right side of his hand. It did a shot of Owen, then when it came back to the British, the string was on the left.
Answer: It is never really mentioned, but we can assume it is the home of some noble or "higher class" person, from all of the elaborate things.