Unvented Crawlspaces
In most climate zones, conditioned crawlspaces perform better than vented crawlspaces in terms of safety, health,
comfort, durability, and energy consumption. Research has demonstrated how these conditioned crawlspaces also do not
cost more to construct than vented crawlspaces. Crawlspace venting is a widely accepted business practice across the
U.S. However, in humid climates, the warm humid air entering the crawlspace is more likely to condense on crawlspace
framing than it will to help dry out the crawlspace. This is because the outside air can often have a dew point that
is higher than the interior crawlspace framing surface temperature. As evidence, existing vented crawlspaces have
experienced serious moisture and mold problems, costing builders and homeowners significant resources to repair.
read more
Crawlspaces
Access openings must be a minimum of 18 inches high by 24 inches wide. Access to all under-floor spaces must be
provided with access openings through the floor not smaller than 18 inches by 24 inches (457 mm by 610 mm).
read more