button_insulationInsulation materials reduce the transfer of heat from one place to another. In Maine homes, insulation reduces the flow of heat from the interior to the exterior in the winter, and in the summer months, from the exterior to the interior. For optimal energy efficiency, your home should be insulated from the roof down to the foundation. When insulation is properly installed, heating systems run less frequently, helping to reduce on-going energy expenses while meeting home heating needs.

atticinsulationInsulation’s ability to reduce heat transfer is rated in terms of its resistance, or R-value. You’ll often see information about insulation conveyed in total R-value. As an example, the Department of Energy recommends that attics in Maine be insulated to R49 or approximately 16 inches deep in a typical attic. The average Maine home is well below that and has an attic insulation level of R13 (e.g. – 3.5 inch fiberglass batt insulation). Efficiency Maine recommends that the entire building envelope be insulated from top to bottom including attics, cathedral ceilings, all wall cavities, rim joists, basement walls, and crawl spaces.

Insulation’s effectiveness depends on material used, how much of it is installed, where it is installed, and if the home has been effectively air sealed. For example, fluffy insulation works great where there is no air flow but does little if the area is drafty or unsealed. Gaps or settled insulation leave spaces for cold air and moisture to flow, while insulation properly installed leaves none of these gaps. There are a number of insulation materials available that range from recycled fiber materials to foam boards to wool.

InsulationDuring a home energy assessment, an energy auditor or insulation contractor will be able to recommend appropriate insulation levels and tell you which insulation materials might work best in certain locations. For example, cellulose insulation is a popular and relatively inexpensive choice for attic insulation. Many homeowners choose rigid foam or spray foam insulation for rim joists and basement walls. Insulating basement walls to at least two feet below grade is highly cost effective. Consulting with an energy advisor is the best way to determine what insulation materials will work best in your home as well as discuss indoor moisture or other health and safety concerns.

US DOE Building America Best Practices Series: Insulation

Taking Action

smallicons_findavendorFind a Registered Energy Advisor or Insulation Contractor Click here to find energy advisors and insulation installers in your area.



House+WinterThumbApply for Efficiency Maine FinancingClick here to find out about Efficiency Maine’s Home Energy Loans for financing insulation projects as well as energy assessments, air sealing, heat pumps and more.


  • Reduced Energy Demand – Effective insulation means that it takes less heat to make your home comfortable and will reduce heating demand no matter what fuel you use to heat your home.
  • Increased Comfort – Insulation projects typically make rooms warmer in the winter and cooler in the summer. Increased insulation levels may also reduce outside noise making your home quieter.
  • Sound Investment – Insulation projects can typically provide cost savings for many decades.
  • Incentives and Financing – Qualifying insulation projects can get up to $1,500 in incentives from Efficiency Maine. Fast and easy Efficiency Maine financing comes with 10- and 15-year terms allowing you to bundle projects and enjoy greater home comfort immediately, and offset loan payments with energy savings.


  • Preliminary Work – Some insulation projects require that building durability, mitigation, or indoor air quality projects be completed in advance of the installation. These projects might range from eliminating moisture intrusion in the basement to removing old knob-and-tube wiring in the attic. An energy advisor or insulation contractor will be able to guide you through these projects. These health and structural improvements can be incorporated into any project that can be financed through Efficiency Maine loan products.