Our blueprints say housewrap and he says he only does what code says he has to do. He wants 1/2" on roof where our plans say 5/8" with clips. Drywall says 5/8" he says he doing 1/2". His bid does not say he can alter the plans, but says that's how they build to code. The house is custom not a spec home. His housewrap was only only the bottom and then the block laid was off square and the framing is sitting 3" off at an angle and they said it was still structurally sound. What do we do?