What are the costs associated with a closed crawl space?
Costs vary for new or existing homes. For new homes, there is very little additional cost between a vented and closed crawl space. With changes to the new building code, the only thing that separates a closed from vented crawl space is the liner on the walls and the absence of vents. Whether you are doing a closed or vented crawl space, new code requires a minimum, 6 mil, over-lapped vapor retarder on the ground and the installation of insulation in either the sub-floor or on the interior of the crawl space wall. But for existing homes, depending on the space, a typical closed crawl space retrofit costs between $2-$5/SF of crawl space. Variables include the current condition of the space, existing insulation, presence of mold or wood rot, water problems, combustion appliances and air sealing. All things considered, the benefits associated with a closed crawl space by far outweigh the costs.
