2.2g Insulation

Feature	Wall, attic and basement insulation prevents heat transfer from inside to outside, depending on climate and season.
Challenges	The least expensive insulation, fiberglass batt insulation, can lose effectiveness if it is installed in a sloppy manner and/or if it settles inside the wall after installation, leaving gaps where heat transfers easily. This creates energy loss, money loss and occupant discomfort. More expensive types of insulation, such as rigid foam with a higher rating, are more effective.
Resources	See Energy Star on properly installed insulation in PDF
	Types of Insulation
Sprayed or Injected Foam	Sprayed or Injected Foam Products are typically made from polyurethane or similar products and are injected or sprayed into cavities where they expand to the desired thickness. (Source: Oikos) Icynene spray foam insulation was installed in the attic of The New American Home 2009 in Las Vegas (shown above). Total utility costs for the 8,721 square foot house, which include electricity and natural gas usage, are expected to be about $2,500 per year (plus service charges). Overall, the home uses approximately 70% less energy for heating and 61% less energy for cooling when compared to a similar home. See the story and more documentation.
Rigid Insulation	Rigid Insulation is typically made from polystyrene, polyurethane, or polyisocyanurate foam, which is expanded or formed into large sheets. Rigid insulation can be used to provide a continuous thermal barrier in basements, crawlspaces, and on exterior walls. (Photo: Western Oregon Builders)
Blown-in Insulation	Blown-in Insulation is typically made from fiberglass or cellulose and is literally blown into the walls and attic through a large hose. Blown-in insulation should completely fill the wall cavities and be an even thickness throughout the attic.
Batt Insulation	Batt Insulation is typically made from mineral fiber (fiberglass or rock wool) and manufactured in blankets of various sizes and thicknesses. Batt insulation is typically fitted between studs, joists, and beams and should fill the wall, floor, or ceiling cavity without any gaps, voids, or compression. (Photo: Johns Manville)
Radiant Barriers	In hot summer climates, attic radiant barriers can help keep homes comfortable and reduce cooling bills. Made of a reflective foil, radiant barriers block the transfer of radiant heat from a hot roof into the attic. In the Southeast, radiant barriers can reduce cooling costs by 8% to 12%, according to the Florida Solar Energy Center. (Source: U.S. Green Building Council)
Tax Credits	Federal tax credit incentives for insulation