Basement Insulation.
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A properly insulated basement can save you money on heating and provide a dry, comfortable living space. In most cases, a basement with insulation installed on its exterior walls should be considered a conditioned space. Even in a house with an unconditioned basement, the basement is more connected to other living spaces than to the outside, which makes basement wall insulation preferable to ceiling insulation.

In new construction, adding insulation on the exterior of the basement walls will do the following:

Minimize thermal bridging and reduce heat loss through the foundation

Protect the damp-proof coating from damage during backfilling

Provide some protection against moisture intrusion

Make the foundation part of the thermal mass of the conditioned space, thereby reducing interior temperature swings

Reduce the potential for condensation on surfaces in the basement

Conserve room area, relative to installing insulation on the interior.