I'm a excavator by trade but help my dad build one to three customs a year. We are starting my sister and brother in laws house In about a month and He wants to spay foam everything 3" of closed cell in walls,4" on concrete basement walls, 4" on rim joist, and at least 2" on the top of drywall in attic for moisture barrier. Then put 20" or so of blown in cellulose or fiberglass overthe foam. All this with Anderson 400 windows and thermatru doors and we glue all bottom plates down and Vulcom joints. We live in northern Illinois and my heating and air guy is concerned about this approach because of sick house syndrome and noway for excess moisture to escape. Just want other professional advice or opinions. I don't know if this is in the right forum topic either so sorry.