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Insulation

A little insulation goes a long way.

You can earn a rebate by improving the efficiency of your home by installing insulation and other thermal envelope measures — including ceiling, wall, and foundation insulation, caulking, window film, etc.

Insulating your home properly will greatly lower your heating and cooling costs. Experts estimate that 40 million single-family homes in the United States need more insulation. Could yours be one of them?

Home insulation

  • Start at the Top. Your attic floor, or the ceiling of your top story, is your building's primary candidate for insulation. You could save as much as 30 percent of your energy costs by better insulating your attic or top floor.
  • Insulate on all Sides. You could save as much as 20 percent of your heating and cooling costs by insulating your exterior walls.
  • Energy Loss Underfoot. You can save about 8 percent of your energy costs by insulating the floor over any unheated areas such as crawl spaces, basements and garages.
  • R value. The following minimum R-values (a number that measures the insulation’s resistance to the passage of heat) are recommended for your home: R-30 ceilings (R-38 for mountain homes and electric heated homes), R-13 walls and R-19 floors over unheated areas.

Other common areas for insulation

Duct insulation

  • Improperly insulated ducts can cause you to lose 10-30 percent of the energy used to heat and cool your home.
  • Use rigid fiber board insulation because it is designed to withstand high temperatures. Wrap around ducts that pass through unheated areas, like a crawl space. You'll need an HVAC contractor to install fiber board insulation in air ducts.
  • Seal cracks or joints with UL-approved mastic sealants and UL-approved plastic or metallic tapes. Do not use cloth-backed tapes.
  • Reconnect or seal off any disconnected ducts to avoid heating spaces you aren't using.
  • If you have any questions about how your duct work is connected, contact your local HVAC contractor.

Pipe insulation

Similar to duct insulation, pipes can release heat when transporting the hot water in your home. Insulating pipes is a great way to increase the efficiency of your hot water system.

Double glazing

Heat escapes through a single pane of glass almost 14 times faster than through a well-insulated wall. Double glazing is when you install another window or door to reduce the heat transfer between the windows or doors. Storm doors and double-paned windows are the best way to insulate attractively, but they can be expensive.

Types of insulation

  • The Value of R-Value, R-value is a number that measures insulation's resistance to the passage of heat. The higher the R-value, the more effective the insulation.
  • Blanket and Batt Insulation. Blankets (continuous rolls) and batts (pre-cut sections) of rock wool or glass fiber are used to insulate attics, walls and rafters as well as underneath floors. They work best where there's a standard space between joists or rafters and few obstructions. Both types are available with or without vapor barrier backing.
  • Loose-Fill and Blown-In Insulation. It's easy to insulate unfinished attic floors with poured-in glass fiber, rock wool, cellulose, vermiculite or perlite insulation. Check to make sure your insulation meets federal specifications. Blown-in insulation is good for filling the nooks and crannies in finished frame walls.
  • Rigid Board Insulation. Board insulation made of polystyrene, urethane or fiberglass works best for outside wall insulation. Some kinds require extra fire safety precautions and should be installed only by a contractor.
  • Use Vapor Barriers. A vapor barrier is a material that reduces the rate at which water vapor can move through a material. Many vapor barriers slow the uncontrolled movement of air, which often contains water vapor. Vapor barriers can help control moisture in basements, ceilings, crawl spaces, floors and walls.

The U.S. Department of Energy can tell you the most economic and effective insulation level that's right for your ZIP code.