2008 U.S. Department of Energy
R-Value Recommendations for New and Existing Homes
The following 2008 Department of Energy zone recommendations are based on comparing estimated future energy savings to the current cost of installing insulation. The DOE gives a range for many locations for the following reasons:
- Energy costs vary greatly over each zone
- Installed insulation costs vary greatly over each zone
- Heating and cooling equipment efficiency varies from house to house
- Best estimate of future energy costs may not be exact.
