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The biggest bang for the buck in home energy savings often comes from insulation. While less glamorous than a shiny new refrigerator or solar panels, adding insulation is typically one of the first improvements experts recommend because it really makes a difference.

In wall radiant heating in the Habitat for Humanity house

Photo Courtesy of DOE/NREL, In wall radiant heating in the Habitat for Humanity house

Homes without enough insulation are like homes without a winter coat when it's cold out. They waste energy and require larger heating and cooling systems than you really need. One benefit of adding insulation that often surprises home owners is the added comfort during hot weather as well-akin to wearing a nice shady hat.

The measurement for insulation is called an R-value, which measures resistance to heat flow. It can also be referred to as thermal resistance. The higher the R-value, the greater the insulating power. All materials having the same R-value, regardless of type, thickness, or weight, are equal in insulating power. The U.S. Department of Energy recommends home insulation R-values based on the different climate zones in the United States. Here are the recommendations for Colorado:






4-inch cavity
6-inch cavity

R-13 or R-15
R-19 or R-21


Under floor
Crawl space


Slab Edges



Basement Walls



Among the benefits of adding insulation are:

Energy Savings

Weatherization Services, DOE Weatherization Assistance Program, Veteran's Green JobsAdding the optimum levels of insulation  can reduce energy bills up to 30%. The amount of energy you conserve will depend on several factors including local climate; the size, shape, and construction of your house; the living habits of your family; the type and efficiency of the heating and cooling systems; and the fuel you use.

Comfortable Living
Uninsulated walls are cold, and they can make you cold because your body heat is drawn to the cold surface. In addition to providing more comfort, insulation is also an efficient way to provide a quieter home as it reduces noise transmission through floors and through walls.

Photo Courtesy of DOE, Weatherization Services, DOE Weatherization Assistance Program, Veteran's Green Jobs

Safety & Indoor Air Quality
Proper installation is essential for insulation to perform properly. Knowledge of vapor retarders, air infiltration, ventilation, recessed lighting, and water pipes are just a few of the areas critical to installation techniques. If you have questions about how to achieve the best results, it is wise to consult an insulation professional.

Boosting a standard insulation level to super-insulated levels reduces carbon dioxide emissions dramatically. Depending on the source of your heat, it is possible to save between 5 and 23 tons of carbon emissions per year just by adding maximum  recommended insulation.
Many materials are used as home insulation, including:

  • Fiberglass, made from molten sand or recycled glass and other inorganic materials under highly controlled conditions. Fiberglass is produced in batt, blanket, and loose-fill forms
  • Rock and slag wool, which use natural rock and blast furnace slag as its raw material. Typical forms are loose-fill, blanket, or board types.
  • Cellulose, a loose-fill made from paper to which flame retardants are added.
  • Foam insulation, available as rigid boards or foamed-in-place materials that can fill and seal blocks or building cavity spaces. Foam is also used in air sealing to fill gaps, cracks, or openings.
  • Reflective materials, fabricated from aluminum foils with a variety of backings such as polyethylene bubbles and plastic film. Reflective insulations retard the transfer of heat.

Hiring a contractor
Professional insulators can blow in insulation using a loose fill or a dense pack processes. These forms of installation will greatly enhance the benefits you experience. Professionals normally use a gas-fired machine to blow in insulation, and fill tubes for dense pack to avoid any gaps in the insulation.

Questions to ask
It is important to find an insulation contractor experienced working in existing homes. Experienced retrofit contractors should take steps to minimize dust and drill holes (when insulating walls). It is up to the homeowner to be sure that an insulation contractor will use drop cloths and clean up after their work; adding insulation in existing homes is a messy job. It is also up to the homeowner to make sure all the insulation paid for is actually installed. Check the entire attic and considering being at home when insulation is added to the walls and other hard to see areas.

Make sure the contractor uses a variety of insulation materials so they can use the best option for different areas of your home. Contracts should be specific including exact R-values (not inches of insulation), where the insulation will be installed, cost, method of payment, and warranty information provided by the insulation material manufacturer

Look for insulation contractors that belong to Insulation Contractors Association of America ( Each ICAA-member insulation contractor subscribes to the ICAA Code of Business Ethics as a condition of membership.

References, licensing, insurance
It is always important to speak with previous customers, check with the Better Business Bureau and ask for verification of the necessary licensing and insurance requirements. Download a ( hiring checklist from the Federal Trade Commission.

Insulating your own home
If you want to install insulation yourself, download this comprehensive home sealing guide from ENERGY STAR (


371374_Electro-Air Whole House Air Filters