The assembly was easy enough and I understand why some of the holes were not pre-drilled. Water proofing will be required and is probably best done prior to assembly. The stairs are not really ideal for dogs. Mine are fearful because there is no backing to each step. Deeper steps may help a little but a backing so their feet do not slip through would be much better. I will add a straight board behind the stairs and non-slip stair treads to see if that helps. Brody, the white dog loves to run up against the fence and jump at passing dogs. I will see how sturdy the house is once he jumps up top frantically trying to get on the other side of the fence. Zuli prefers the lower level but will lay comfortably on top if placed there. The picture shows Brody with all his hair and he looks too big for the top but when shaved he fits just as comfortably as Zuli. It is quite nice for the price and a covered patio.