We continued looking for ways to seal a house properly BEFORE insulating. If I can summarize a few ideas that stood out for me. "Put a lid on it" says it all. By stopping the airflow escaping through the top of the house, by proper sealing and insulation, one can control the amount of unconditioned (unheated or uncooled air) exterior air from entering the home. A law of physics dictates, one CFM in = one CFM out. In other words, if a leak under a door brings in a cubic foot of exterior air, that same amount of air will leave your home. The air you just paid to heat! That makes a whole lot more sense to me than being yelled at "Were you born in a barn?!" when I left a door open as a child. Another eye opener, fiberglass insulation batting is the least desirable of choices given that it often shifts, is installed improperly, and often has gaps. Dave Hutchins from Energy Trust taught the class, and has years of field experience. He gave me a few company names who he feels does exceptional work carrying out a customized Home Performance Review. They are Trade Ally contractors, so they can do both the review (which I hear can cost several hundred dollars) and/or the recommended work. Please give me a call if you're interested, I'd be happy to share.