Synopsis: Installing insulation as a house is being built is easy to do. Beefing up the insulation in an existing home is a tougher task, especially when you don’t know what insulation – if any – is already in place. Senior editor Justin Fink takes a look at the most common types of insulation that exist in homes today, including balsam wool, urea-formaldehyde foam, vermiculite, fiberglass, rock wool, and cotton batts. Fink then provides information on contemporary insulation upgrades, such as rigid foam (EPS, XPS, and polyiso) and blown-in options (cellulose and fiberglass). This article includes sidebars on determining what type of insulation is already in walls and on ways to remove old insulation (if that is necessary for performing an upgrade). Plus, use our Insulation Upgrade Payback Estimator to estimate how long it will take to payback your investment based on savings in energy costs.

When it comes to insulating floors, walls, and ceilings, nothing compares to the blank canvas of a newly framed house. The house is wide open, so contractors can add any type of insulation they want to achieve the best possible thermal performance. Those guys have it easy.

What about us remodelers, though? The people living in houses built with minimal insulation, or none at all? The ones who don’t have the luxury of gutting their walls? The ones who work on or live in houses that hemorrhage heat in the winter and bake like an oven during the summer? What can we do to improve the thermal performance of these homes? A lot, actually.

Techniques and materials for retrofitting insulation in old walls have improved over the years. Many times, insulation can be added from the interior or exterior of the house without gutting the walls. Even so, I’m not going to sugar coat…