Constructing Closed Crawlspaces
A closed crawlspace – also referred to as an unvented, conditioned, or sealed crawlspace – is a dry, energy-efficient, and practical option for residential construction.
The benefits of a closed crawlspace include:
- Dryness and durability resulting from the air sealing, insulation and moisture control measures.
- Marketability to homebuyers – raised wood floor homes provide enhanced curb appeal plus a warm and comfortable living area that can be marketed to buyers.
- Suitability to sloped and infill sites, as well as challenging soil conditions.
- Simplified scheduling of trades and inspections.
- Improved whole-house energy efficiency – closed crawlspace temperatures are more stable compared to an attic or a vented crawlspace; locating ducts and mechanical equipment in the space reduces heating and cooling loads.
- Simplified HVAC installations – provides access for installation and maintenance of plumbing and mechanical systems; changes to floor plans are simplified.
To help homebuilders transition from traditional slab-on-grade foundations to a raised wood floor, SFPA and Home Innovation Research Labs have developed a new package of educational materials specifically designed for building professionals. These materials include a six-page TechSpec report and a four-part video series.
Beyond a discussion of the benefits, the TechSpec “Making the Transition” addresses code considerations, best practices, foundation walls, height and access, wood floor framing, moisture management, air sealing, insulation, and mechanical systems. This information is consistent with the provisions of the 2012 International Residential Code (IRC), and focuses on warm and mixed-humid climate regions in the Southeast (Climate Zones 3A and 4A).
A new series of instructional videos take builders through the various stages of closed crawlspace construction and address specific topics in greater detail: