Home Innovation Research Labs Releases New “How To” Resources on Constructing Closed Crawlspaces

Closed crawlspaces, also called unvented, conditioned, or sealed crawlspaces, are dry, energy-efficient, functional, and practical options for single-family new construction, but they are a relatively new construction practice. To help residential builders more readily incorporate closed crawlspaces into their homes, Home Innovation Research Labs in partnership with the Southern Forest Products Association created a new bundle of educational materials specifically designed for builders and trades. The resources include a downloadable TechSpec and a four-part instructional video series – all are available online at no cost.

The first new resource is a TechSpec, “Closed Crawlspaces: Making the Transition,” designed to be an easy-to-read summary of the technology that addresses its benefits and key steps when transitioning from more traditional slab-on-grade or conventional vented crawlspace construction, or improving existing closed crawlspace design and construction practices. 

As highlighted in the TechSpec, benefits of a closed crawlspace include:

• Dryness and durability as a result of the insulation, air sealing, moisture control measures, and conditioned air in a closed crawlspace.
• Marketability to homebuyers – raised wood floor homes provide architectural appeal and a warm and comfortable walking surface that can be marketed to prospective buyers.
• Applicability for sloped and infill sites, and 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, and locating ducts and mechanical equipment in the space reduces heating and cooling loads.
• Simplified installation of mechanical systems – provides access for installation and maintenance of plumbing and mechanical systems, and allows for changes to floor plans.
• Limited learning curve for trades due to the use of familiar materials and methods.

In addition to discussing the benefits, the “Making the Transition” TechSpec addresses code considerations, best practices, foundation walls, height and access, wood floor framing, moisture management, air sealing, insulation, and mechanical systems. The information presented is consistent with the provisions of the 2012 International Residential Code (IRC), and is focused on warm and mixed-humid climate regions in the southeast (Climate Zones 3A and 4A).

Beyond the summary information in the TechSpec, this educational resource bundle also includes a series of four instructional videos online that walk builders through the various stages of closed crawlspace construction and address specific hot spots in greater detail.  The four videos are:

• How to Build a Closed Crawlspace in Climate Zones 3A and 4A
• Hot Spot: Closed Crawlspace – Sealing the Ground Vapor Retarder to the Wall
• Hot Spot: Closed Crawlspace – Installing Wall Insulation
• Hot Spot: Closed Crawlspace – Ventilation

For more information on this construction technique of the newly-created materials, contact Home Innovation Research Labs.

ABOUT: Home Innovation Research Labs, located in Upper Marlboro, Md., is a full-service research, testing, and consulting firm determined to improve the quality, durability, affordability, and environmental performance of single- and multifamily homes and home building products – in short, we aim to perfect the home. Founded in 1964 as a subsidiary of the National Association of Home Builders (NAHB), our team has been integral in solving many of our client’s most difficult product and technology issues, and helping to introduce some of the most groundbreaking innovations in construction. Through an interdisciplinary research approach – including market research, building science analysis, laboratory testing, and standards development – we help to find a home for innovation in the construction industry.

NOTE TO EDITORS ON STYLE USAGE: To identify this company and its work correctly, first reference should be "Home Innovation Research Labs." In subsequent mentions, “Home Innovation” should be used; we are not identified by an acronym. Prior to February 12, 2013, the company was known as the NAHB Research Center.