The national requirement for thermal insulation varies depending on the climate you live in. The warmer the climate you live in the lower the requirements for thermal insulation. The colder the climate the greater the requirements are for thermal insulation. Each wall type, floor type, and ceiling type has a different requirement and each building department has adopted a custom version of the requirements. The following chart represents commonly used wall and ceiling assemblies with R value requirements and where the R value should be installed. This chart does not represent all the options and configurations available in your local market. For a complete 2009 IECC analysis of your home call or email one of our professionals. 

Exterior Wall AssembliesZone 4Zone 5Zone 6Zone 7 & 8
Wood Framed (All)13202021
Concrete wood furred – Interior side810911
Concrete wood furred – Exterior side571010
Crawlspace wall – Interior side58813
Crawlspace wall – Exterior side55510
Other AssembliesZone 4Zone 5Zone 6Zone 7 & 8
Under Slab10 – 2′ from perimeter10 – 2′ from perimeter10 – 4′ from perimeter10 – total area
Under Heated Slab15 – 2′ from perimeter15 – 2′ from perimeter15 – 4′ from perimeter15 – total area
Ceiling Insulation38384949
Garage Ceiling wiht Living Above19303038
Floor over crawlspace19303038
Interior floors19191919
Climate Zone Requirements