Attached Link: 3d Warehouse

If you don't mind converting them and if you can accept the textures or make your own, Google 3D Warehouse has just about any building you can think of. Detail varies greatly - some are just shapes with photo textures applied but some are quite detailed, even including interiors.  Some of them were modeled by professional architects. Unrendered view of one of their houses.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken