Residential Insulation


Heating and cooling account for between 40-60% of energy used in U.S. residential buildings. This represents a large opportunity to save energy throughout U.S. buildings. One of the leading cause of energy waste from heating and cooling in both commercial and residential buildings is inadequate insulation.


Proper insulation is a key element for a more comfortable and energy efficient home. It is important to have a continuous boundary of insulation between the conditioned, indoor spaces and the unconditioned, outdoor spaces. This boundary is referred to as the building envelope and consists of the walls, floor, and ceiling or roof and it provides the thermal barrier between the indoor and outdoor environment. Insulating ceilings, walls, and floors decreases the heating or cooling needed by providing an effective resistance to the flow of heat.

Advanced Code Options

There are many new and innovative insulation products not specified by the model codes that can save energy, money, and enhance thermal comfort.

Residential Policy Options

The following section provides examples of these types of code improvement language or methodologies in these areas.

  • Offer Alternative Compliance Option Through HERS Rating
    • Massachusetts Building Code for One- and Two-Family Dwellings, Seventh Edition (780 CMR): Chapter 61, Section 6101.1 amending 404.7 such that a building with a HERS score of 100 or less will be in compliance in lieu of building to 2006/2007 IECC specifications:
      “A proposed building, for which the builder or the buyer obtains a Home Energy Rating by an accredited Home Energy Rating System (HERS), will be considered to comply with the intent of Section 4 if the rating score on the building is 100 or fewer points.”
  • Mandate fuller insulation and air sealing for common walls in low-rise multifamily dwellings
    • Language from the proposed 2009 ECCCNYS (New York state energy code) derived from the EPA and NYSERDA Energy Star Homes programs addresses common walls that they are often direct connections between the outside, unconditioned crawlspaces or basement, and unconditioned attics. This can often result in tremendous air infiltration/exfiltration issues and conductive heat loss, since these walls are no longer insulated either. The end result is energy loss, utility bill increases, and major comfort issues associated with these "cold" walls.
    • 402.2 Specific Insulation requirements (Prescriptive).
      402.2.4 Common/Party/Fire Walls: "Whenever continuity of the Building Thermal Envelope is broken at walls separating dwelling units, such walls shall be insulated to no less than R-10 on each side of the break in insulation continuity, and the walls shall be air sealed in accordance with Section 402.4.1 of this Chapter. – draft language by Michael C. DeWein (BCAP) for proposed 2009 ECCCNYS