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 Assemblies | Zone 4 | Zone 5 | Zone 6 | Zone 7 & 8 |
| Wood Framed (All) | 13 | 20 | 20 | 21 |
| Concrete wood furred – Interior side | 8 | 10 | 9 | 11 |
| Concrete wood furred – Exterior side | 5 | 7 | 10 | 10 |
| Crawlspace wall – Interior side | 5 | 8 | 8 | 13 |
| Crawlspace wall – Exterior side | 5 | 5 | 5 | 10 |
| Other Assemblies | Zone 4 | Zone 5 | Zone 6 | Zone 7 & 8 |
| Under Slab | 10 – 2′ from perimeter | 10 – 2′ from perimeter | 10 – 4′ from perimeter | 10 – total area |
| Under Heated Slab | 15 – 2′ from perimeter | 15 – 2′ from perimeter | 15 – 4′ from perimeter | 15 – total area |
| Ceiling Insulation | 38 | 38 | 49 | 49 |
| Garage Ceiling wiht Living Above | 19 | 30 | 30 | 38 |
| Floor over crawlspace | 19 | 30 | 30 | 38 |
| Interior floors | 19 | 19 | 19 | 19 |
Climate Zone Requirements