How do I know the insulation thickness for walls?

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Wall Insulation Recommendations

Plan your exterior building wall insulation based on the recommendations, guidelines and codes established for your particular area. Building insulation requirements are based on area climate and general weather conditions. In colder regions, recommendations are for thicker and more effective insulation properties; in warmer regions, recommendations are for thinner, or sometimes even absent, insulation properties.

Examples of Wall Insulation Recommendations

Learn about wall insulation code requirements in your area through the links provided. A couple of random samples will provide a sense for what is called for in the specific areas searched.

Illinois zip code 60021 (Fox River Grove) needs to have wall insulation with R-20, consisting of R-15 within the wall space, plus R-5 exterior sheathing.

California zip code 92167 (San Diego) needs to have wall insulation with R-13 in the wall space only.

Note: Insulation is rated by way of "R-value," which represents a material's "thermal resistance" (i.e., resistance to heat passing through it). The R-values of insulation differ by product, through material design, thickness, vapor-barriers, placement and other factors.

Check Local Requirements

Contact your local building inspector's office for more specific guidelines and requirements for wall insulation in your area. In addition, do some of your own online research into wall insulation "best practices," products, and installation and maintenance help.