Normally I don't get too excited about insulation. I don't suppose you do either. But it's a key factor in making a structure into a complete and comfortable energy-efficient home. Properly installed, insulation with the R-value required by the building code helps keep a home warm in the winter and cool in the summer. Of course, that helps keep those utility bills down. Perhaps that's why some customers do get excited about insulation.

What about housewrap? Does it increase the R-value? Is it better than the 15-pound felt that we're all used to? Building paper helped make a structure weathered-in (waterproof from wind-driven rain) before the siding was installed. It also increased the effectiveness of the insulation and reduced drafts from the outside. Air infiltration and moisture buildup are major problems common to many homes, especially older ones.

Today, modern housewraps act as a weather barrier, yet they're permeable to release moisture vapor trapped within wall cavities. These materials actually allow a home to breathe, letting moisture vapor escape before it leads to condensation and eventually mildew and rot. Housewrap still stops penetration by wind-driven rain, as well as air or wind penetration through seams, cracks, or directly through a wall cavity. Temperature changes within the walls mean more energy to heat homes because the walls are lower in temperature. And in warm climates (or during summer), warm air moving inside a wall cavity means that more energy is required to cool the house.

To create a high-performance insulating system, first apply caulk or foam sealant to fill all seams, cracks, openings around the top of the foundation, and around any water or electrical lines that pass through exterior walls, floor, and ceiling areas. Then install the insulation. This creates a tighter building envelope and prevents air and wind penetration. It may cut down air infiltration by 50 percent compared to homes where these sealants haven't been applied.