Minimum Levels Of Insulation
The U.S. Department of Energy recommends the following R values of insulation for renovations of homes located in New England. The recommendations are cost-effective levels of insulation for this area.
Recommended R Values for Existing Homes
Ceilings/Attic = R49 to R60
Walls = R11 to R22
Floor = R25 to R30
Basement / Crawl Space Walls = R11 to R19
Energy Code Regulations
Most states (NH for sure) require that new homes that are built meet certain energy code minimum values. The minimum values are based on the recommendations for the U.S. Department of Energy. In NH, the New Hampshire Public Utilities Commission oversees the compliance of the state energy code requirements.
Here in NH a building’s insulation performance is actually evaluated based on the entire system including insulation, windows, doors and HVAC components. For new construction the structure must be evaluated using the Energy Code in order to determine if the proposed building has sufficient insulation. Here in NH the Energy Code requires new construction and additions to be certified by a Professional Engineer or Architect. Otherwise the structure can be checked using the states REScheck software and submitted to the State for approval.
Most states, towns and government bodies require that the energy code compliance be issued as part of the building permit process. This ensures that the minimum energy code requirements are met and home owners are getting what they pay for.