Exterior Insulation for Existing Foundation Walls Description Guide describing how to insulate a new foundation wall or an existing foundation wall by adding rigid insulation to the exterior side.
Insulation for Existing Crawl Space Floors Description Guide describing how to upgrade a crawlspace floor in an existing home by adding insulation.
Spray Foam Interior Insulation for Existing Foundation Walls Description Guide describing how to insulate an existing foundation wall by adding spray foam insulation to the interior side of the wall.
Unvented, Insulated Crawlspaces Description Guide describing methods for insulating an unvented crawlspace or conditioned basement with rigid foam on the interior side of the walls to provide an insulated space for HVAC equipment.