Insulated foundations have become
the norm in recent years in the
Northeast, but there are many ways to
achieve the desired strength and insulation
value. It's important to decide
what R-values you want before you
select a system, since some methods
lend themselves to achieving high Rvalues
and some don't.
The criteria I use to determine
appropriate R-values below grade
Building code requirements.
Increasingly, building codes are
addressing foundation heat loss. In
New York State the code requires R-
11 insulation. But there is a "flexible"
component to the code that allows
reduced R-values in one part of a
house when another part exceeds
code, and when the net effect on the
building's energy performance will be
Expected use of