How should full basements, the most
common type of foundation in New
England, be insulated? There are many
approaches that work fine in particular
situations, of course, but for most applications,
I believe the methods covered here
will result in the best performance with
the least worry.
1. Assume the basement will be
heated. Insulate the foundation even if
your clients don't expect to heat it. Otherwise,
if they later decide to turn the basement
into a living or working space, dealing
with retrofit insulation will be difficult,
expensive and probably not entirely
satisfactory.
In addition, an insulated, tight foundation
means greater comfort upstairs with
fewer drafts, as well as better drainage and
a reduced risk of frost heaves.