Adding
wall insulation is like giving your house snug, cozy socks. It can make your
home more comfortable and quiet, plus potentially guard against moisture damage, freezing
pipes, and even fires, according to
Lawrence Berkeley Labs.
Insulation
is particularly essential if there's a dramatic difference between how it feels outside
and how you want it to feel inside. (So...everywhere but San Diego.)
Adding insulation with an R-value of at least 11 to exterior walls can make home heating
and cooling more efficient...and thus, cheaper. Insulating to an even higher R-value can provide
additional savings. R-values measure a material's resistance to heat flow, with higher R-values
providing more insulation.
1. Do some sleuthing to determine if wall cavities already have insulation. Remove an
outlet cover on an exterior wall and peer into the wall cavity. Alternatively, choose a closet
or cabinet along an exterior wall and drill two 1/4" holes into the wall about 4 inches apart,
with one hole above the other. Any insulation should be apparent.
2. If you don't see any insulation inside the wall cavity, hire an insulation contractor
to blow cellulose or fiberglass insulation into the exterior walls. Blown-in insulation does not
require the walls to be torn open (plus, it sounds dramatic).
Insulate to at least R-11. In a typical home, half or more of the energy loss is through the exterior walls, floor, and roof (the home's "shell" or "envelope"). Exterior walls can be the most important part of your shell to insulate, because of their large area.
Make sure contractors bid for the same R-value. Compare contractors' bids for the same insulating value (R-value), not just the same number of inches.