Dude101 said:http://mutantsrising.com/uploads/images/mr/huge.jpg
If the backside exists too as graphic, it would be possible to include that whole fat building into the game with the FOnline engine and you wouldn't need more like approx 10 tiles.

A good value for maximum tile size in the FOnline engine is approx 500x500px. But this is not really the maximum, it's just for loading speed and graphic cache, etc.