It depends on the type of paint used on the house. If it is latex paint, then it will likely be damaged since latex paint is not meant to withstand high pressure washing. However, if it is an oil-based paint, then it should be able to withstand high pressure washing.

It depends on how powerful the pressure washer is and how close the nozzle is held to the surface of the paint. If done incorrectly, power washing can strip away the paint or primer and even damage the underlying surfaces. It's always best to test a small area first to see if there's any adverse reaction before doing an entire house.