Rule Your Attic to Save Energy and Stay Comfortable

ENERGY STAR / 4 min read

According to the energy experts at ENERGY STAR, 9 out of 10 homes in the U.S. are under-insulated. Sealing and insulating your home is a simple and cost-effective way to save money, improve your comfort and reduce your carbon footprint. Thankfully, it’s easy to check insulation levels and determine if your home is one of those that could use some help.

With help from ENERGY STAR’s Rule Your Attic program, all you need is a ruler or tape measure to get started.

R-Value: One Size Does Not Fit All

Insulation ratings are measured in R-values per inch of thickness. An R-value tells you how well a type of insulation can keep heat from leaving or entering your home. Insulation R-values vary based on the type, thickness and density of the insulation material. Typically, a higher insulation R-value means better climate control and better energy efficiency for your home. A higher insulation R-value usually means a higher price point as well.

For every type and material of insulation, check the R-value per inch of thickness that the manufacturer has listed. In general, the insulation’s method of installation can give you an idea of how it compares to other types of insulation.

Your home doesn’t necessarily need the highest R-value insulation. The R-value your insulation needs depends on your local climate.

The map above shows each region of the U.S. and the Department of Energy’s corresponding climate zone. Once you find your home’s zone on this map, you can use the below insulation R-value chart to determine the minimum R-value your insulation should have.

Do You Need More Insulation?

Once you know the recommended R-value for your home, and you’ve measured your insulation, a little bit of math will reveal any gap. If you need to add insulation, the next step will be to determine what type and how much insulation you need. Refer to this Eco Actions project for details.

Beyond the Attic

While the attic is a key area for boosting insulation, it’s not the only spot in your home that is insulated. Walls, basements and crawlspaces also require insulation. In particular, exterior walls should be fully insulated. To find out how to safely check your home’s wall insulation using an electrical outlet, refer to ENERGY STAR’s DIY Checks and Inspections. Likewise, there are helpful guides for determining how much insulation you need for your basement. The level of insulation varies depending on whether you have an unfinished basement, finished basement or enclosed crawlspace.

The Benefits of Insulation

Reduce your energy bill by up to 20%

Heating and cooling typically account for half of household energy costs. Attic insulation is one of the most effective ways to reduce heat loss in the winter and heat gain in the summer. If your home is under-insulated, that means your seasonal energy costs could be up to 20% higher than they should be.

Improve your HVAC unit’s performance & longevity

Insulation is part of a whole-house energy efficiency solution. A well-insulated home keeps your HVAC unit from running constantly and straining to keep your house cool or heated. Along with HVAC maintenance and tune-ups, properly installed insulation helps preserve the longevity of your HVAC unit.

Sealing your Home

The roof, walls, windows and doors that make up your home are its envelope. A leaky envelope leads to higher energy bills during the hottest and coldest times of the year. Sealing your home’s envelope is a two-part process consisting of sealing leaks coming into the house and those leaking out of the house. Once again, the experts at ENERGY STAR have a series of DIY tests for locating leaks.

Once you know where the leaks are, you can eliminate them using caulk, weatherstripping and expanding foam. To know which product to use for various leaks, refer to this list from the insulation experts at The Home Depot:

  • Use caulk to seal along baseboards and recessed fixtures, and around window and door frames.
  • Use weatherstripping and door sweeps to seal the moveable parts of windows and doors.
  • Use expanding foam to seal large gaps around vent and pipe entrances.

More Projects and Products

If you are shopping for insulation and looking for environmentally responsible products, be sure to read about the steps Owens Corning has taken to expand their use of recycled content in their products.

Check out our Eco Actions project library for more ideas to help save energy and reduce your carbon footprint.