This Top Innovation profile highlights Building America research into the benefits of closed, conditioned crawlspaces over traditional vented crawlspaces. Crawlspace vents are supposed to prevent moisture problems, based on the assumption that fresh air entering through vents on one side of the house would push out moist air on the other side. However, in humid climates, the air from outside is often more moist than the air in the crawlspace, leading to structural, mold, and pest problems.

Building America research on unvented crawlspaces has demonstrated energy savings of 15% to 18% for heating and cooling while reducing humidity over 20%. These results have substantially influenced changes in the 2009 and 2012 versions of the International Residential Code (R408.3) allowing unvented, conditioned crawlspaces. Thousands of homes have now been constructed with this important innovation. Read about this Top Innovation.

See an example of this Top Innovation in action. Find more case studies of Building America projects across the country that demonstrate unvented, conditioned crawlspaces.

View other Top Innovations in the Advanced Technologies and Practices category.