I am building a house at the eastern end of a 5 mile lake in NH. Air infiltration from the significant western winds that buffet the house cool it despite the house wrap, cedar siding, R19 fiberglass insulation and poly vapor barrier. I have found that using silicone caulk where the studs meet the sheathing and where the 2x6's meet have reduced the air infiltration alot.

Can I place rigid polystrene between the studs, caulk around the edges of the polystrene, replace the fiberglass and poly vapor barrier without causing a problem? Are there any other methods for reducing significant air infiltration due to 40-60mph winds.

Kat, investigate the spray in insluations, such as - GOOGLE CELLULOSE SPRAY-ON INSULATION.... n'This is sprayed on wet and drys tight and is trimmed off right at the studs and our neighbors house is airtight from the high winds here. It gets in everywhere, behind wiring, plumbing and framing...

I take it you are retro-fitting? If I were to use the rigid insulation, I think I'd want a professional grade expanding foam caulk to really make a good seal.

This will be expensive if you do much of it. If this is new construction, I'd reccommend researching cold-climate systems that wouldn't require such intensive detailing.

Either way, pay full attention to sealing at plates, corners, wiring penetrations, window casings, etc etc. I've seen "super-insulated" houses with gale force drafts blowing through the walls. The entire system needs to be integrated.

What lake?

Pete