While it isn’t pretty, insulation and air sealing provide the biggest bang for your buck when it comes to home energy efficiency improvements. When installed together, they help save money and make a big difference in comfort and energy use.

Insulation rating

Insulation is rated in R-value. The R stands for resistance to heat transfer. The higher the R-value, the slower the heat transfer, or less wasted energy. Types of insulation include fiberglass batts, blown fiberglass, cellulose and foam. Each has its own R-value listed on the packaging. To determine the R-value of your existing insulation, multiply the number of inches by the R-value per inch for the type of insulation.

Insulation level recommendations are based on geographic location. Generally, the colder the climate, the higher the recommended R-value.

Where to insulate

The best locations to insulate include the attic, walls and floor. If you have a forced-air heating or cooling system, ductwork needs insulated, too. You want a consistent thermal barrier around your home for maximum efficiency. A bonus to insulation, it reduces outside noise.

Attic insulation minimizes energy waste and helps maintain a consistent temperature throughout the home. Combined with air sealing, it can prevent ice dams from forming on the roof in colder climates.

Attics can be insulated using batts or blown-in insulation. Recommend R-values range from R-38 to R-60 in Illinois. If you use your attic for storage, you can build a raised platform with room for insulation underneath. Add insulation and weatherstripping to access doors or hatches.

Exterior walls and walls separating heated and unheated areas of the home (such as garages or enclosed porches) should be insulated to an R-value ranging from R-13 to R-21, based on your location and wall construction.

Wall insulation can be installed during construction or a remodel. If your home wasn’t insulated when built, have insulation blown in by a contractor. Blown-in options include cellulose, fiberglass and foam.

Your home should also be insulated between the floor and crawlspace or unheated basement. If your basement is heated, install insulation in the box sills—the area between the foundation floor of the home’s main level.

Consider building and insulating the exterior walls in the basement or installing foam insulation on foundation walls. Check local building code requirements. Recommended R-values for floor insulation range from R-25 to R-30 in Illinois. Also insulate heating and cooling ductwork located in unconditioned spaces to prevent energy waste.

Importance of air sealing

Air sealing prevents drafts and air infiltration from outside. It can improve efficiency, comfort and indoor air quality.

Air sealing can be done as a DIY project, but it is challenging to pinpoint and properly seal air leaks. Consider hiring a contractor to complete a blower door test and seal leaks.

Typically, air sealing is done around plumbing and electrical penetrations with spray foam or caulk. If using spray foam around gas appliances, temporarily turn off pilot lights. Spray foam is flammable.

Sheet metal and high-temperature heat-resistant caulk should be used to seal gaps between framing, chimneys and metal flues.

DIY considerations

With a DIY approach, protect yourself when going into spaces with insulation. Wear a properly fitted mask or respirator. Wearing a Tyvek suit and gloves is recommended. Also, kneepads come in handy when crawling.

Before a DIY approach for air sealing, research best practices for proper home ventilation. Also, contact several local contractors for an estimate. Sometimes the contractor can get cheaper bulk pricing on insulation.

Making insulation and air sealing a priority adds comfort, efficiency and savings to your home.

There are different types of insulation, including fiberglass batts, blown fiberglass, cellulose and foam. Each has its own R-value, which is listed on the packaging. Photo courtesy of Mark Gilliland.