(R7.2) Put a Lid On It Part 2: Unvented Crawlspaces

Bringing attic and crawl spaces inside the thermal envelope is a great way to simultaneously improve energy efficiency and moisture management. One of the main ways unvented attics and crawl spaces reduce energy waste is by bringing ducts and air handlers inside (which is a requirement of NYStretch and the NYCECC). This can also be cost-effective for builders as they eliminate the requirement for duct testing. But there are risks associated with installing these assemblies improperly, so it is important to meet all related requirements in the RCNYS. For unvented attics, these include a minimum R-value of air impermeable insulation or above-roof deck insulation and proper installation and location of vapor retarders. For unvented crawl spaces, builders must take care to install vapor barriers over exposed earth and provide a means of evacuating moisture. For both strategies, the use of spray foam also brings in fire safety requirements from the RCNYS for thermal or ignition barriers.

Learning Objectives:

1- Describe the energy efficiency benefits of unvented attics and crawl spaces

2- Describe durability benefits of unvented attics and crawl spaces 3- Understand energy code requirements related to these assemblies

3- Understand energy code requirements related to these assemblies