Insulation is needed in homes for many reasons: cost and energy savings, comfort, and even noise reduction. Depending on the climate where you live, the amount or type of insulation you need varies.
Insulation materials slow the flow of heat. In winter, it will slow the flow of heat from inside the home moving out, and in summer it slows the flow of heat from the outside in. The better insulation you have, the slower that flow will be, saving you on heating and cooling costs.
Insulation R-values refers to how much insulating power you need or have in your home. The higher the R-value, the more heat the material resists. The R-value is determined by the type of material used, the density, and the thickness.
The map and table below, from Insulation Institute, shows the insulation R-value needed based on location in the United States.
| Zone | Attic | Wall Cavity | Floor |
| 1 | R30 to R49 | R13 to R15 | R13 |
| 2 | R30 to R60 | R13 to R15 | R13 to R25 |
| 3 | R30 to R60 | R13 to R15 | R25 |
| 4 | R38 to R60 | R13 to R15 | R25 to R30 |
| 5 | R38 to R60 | R13 to R21 | R25 to R30 |
| 6 | R49 to R60 | R13 to R21 | R25 to R30 |
| 7 | R49 to R60 | R13 to R21 | R25 to R30 |
| 8 | R49 to R60 | R13 to R21 | R25 to R30 |
“This map shows thermal recommended levels of insulation for various climate zones, based on recommendations from the U.S. Department of Energy (DOE) and the International Energy Conservation Code (IECC). The IECC is the model building code for the United States.” (insulationinstitute.org)
When building or renovating, consult with your contractor to determine what type of insulation is best for your home and location.