A. I tend to agree with your contractor. I have never been big on a really tight house. Back in the late 70's when energy costs forced everyone to start to think about conservation, many building codes were written that forced us to tighten houses up to the point that people began to get sick from indoor air pollution. The solution was to install expensive air-to-air heat exchangers or just run a bathroom fan for 2 or more hours a day.

I have always used 15# felt on the exterior of the house because I think that house wrap is an unwarranted expense. The felt is supposed to block drafts, but will allow the house to breath.

I also don't have a problem with the paint as vapor barrier concept. If you are concerned about drafts or moister invading your walls, spend your money on sealing wall penetrations...electrical boxes and the like. Also be sure that the painters do a good job of caulking the trim to the wallboard. One thing I left out in my own house is a good seal at the base of walls. This allows air to move through and any carpet will act as a filter. Our light colored carpet now has a permanent dark tint around the walls.

Now that I have written this, I noticed that I seem to be recommending installing plastic in my response to another question . In that question, the discussion was about a barn, and it is possible that the plasterboard is only fire-taped in such an installation. I still agree that a good sealing drywall primer will work as a vapor barrier.