"In the United States, residential rental buildings are depreciable over a 27.5 year or 40 year life, other buildings over a 39 or 40 year life, and land improvements over a 15 or 20 year life, all using the straight line method."

Basically the only thing that will appreciate when owning a house is the land it sits on. A really nice house in a crappy area is going to lose value until the demand for the location starts going up again.