An Alliance to Help Illinois Residents Lower Their Energy Costs

Seal air leaks around your home

  • Cost: $30
  • Yearly Savings: $150-300 ?

    How are savings calculated?

    Yearly savings are estimated for a standard home in the Chicago area with the characteristics you select above. We estimate savings based on government data, local weather patterns, energy prices, and scientific papers. Your actual savings will depend on your home, behavioral patterns and equipment.

    If you're interested in more details, read on!

    We disaggregate energy use for each house type into space heating, water heating, cooling, and appliance end uses using the method developed by the U.S. Department of Energy for the Residential Energy Consumption Survey (RECS), and these disaggregations serve as inputs into the calculations. Calculations are based on engineering models taken from numerous sources including peer reviewed publications, National Institute of Standards and Technology (NIST) handbooks and reference materials, the Environmental Protection Agency's (EPA) Energy Star Program, various utility technical resource manuals, and other similar sources. Additional sources of data include secondary housing characteristics data at the zip-code level from the U.S. Census, hourly weather data from the National Climate Data Center, and incoming solar radiation data from the National Renewable Energy Laboratory.

    Dollar savings from actions are calculated based on the latest available monthly electricity price for ComEd. Natural gas, propane, and fuel oil prices are taken from latest statewide monthly average price data from the EIA. State-specific tap water prices (per gallon) are taken from the 2006 Water & Wastewater Rate Survey.

    We determine carbon emissions from electricity use based on North American Electricity Reliability Corporation (NERC) subregion level emission factors based on fuel mix and generation efficiency data from the EPA's eGRID. Emission factors also include state-level average transmission losses based on data from the Energy Information Agency (EIA) and indirect emissions associated with the fuel-cycle, plant construction, and plant decommissioning of natural gas, nuclear, oil, coal, solar, wind, biomass, geothermal, and hydro power based on P.J. Meier's "Life-Cycle Assessment of Electricity Generation Systems and Applications for Climate Change Policy Analysis" (2003). Direct emissions from natural gas, fuel oil, propane, gasoline, and diesel use are calculated based on standard emission factors from the EPA and estimated fuel-cycle emissions from Meier (2003).

  • Carbon Reduction:19320-38640 lbs CO₂ ?

    What do these tree icons mean?

    The number of trees represent how much less carbon dioxide (CO2) your home energy usage will introduce into the environment if you take the corresponding energy-saving action. Or, put another way, they tell you about how much you can reduce your carbon footprint by taking each action. One tree signifies a small CO2 reduction. Two trees signifies a medium-sized reduction. Three trees signifies a large reduction.

    If you're interested in how we chose the 1-3 tree scheme, read on!

    • 1 tree: Actions that reduce up to 400 lbs. of CO2 annually. These actions tend to be behavioral in nature, or if they rely on techonology, it's simple technology: for example, closing your blinds during sunny summer days, and putting an insulating wrap on your water heater.
    • 2 trees: Actions that reduce between 400-1000 lbs. of CO2 annually. These tend to be actions that rely on using efficient devices that are generally easy to find and install, for example, low-flow showerheads and CFL bulbs.
    • 3 trees: Actions that reduce more than 1000 lbs. of CO2 annually. Generally these are actions that involve upgrading key heating, cooling or insulation systems, for example, installing an efficient furnace or central A/C system. For many such actions, most people will want to have a professional contractor perform the installation. It's also these high-effort, high-impact actions that most frequently have incentives to make follow through easy and affordable.

    What carbon means to you and me...

    • 1 car off the road = 11,133 lbs CO2 per year
    • 1 mile driven = 0.9 lbs CO2
    • 1 100w lightbulb = 170 lbs CO2 per year
    • 1 100w lightbulb for 1 hour = 0.16 lbs CO2
    • 1 barrel of oil = 948 lbs CO2

    Click here to learn more about the science of climate change.


  • Save up to 35% of your annual heating and cooling costs.
  • Eliminate vexing drafts during the winter.
  • Spend less time waiting for your home to heat up or cool down.

Between 15 and 35 percent of the energy used to heat and cool the average home is lost due to air leaks that are easily fixable around the house. Sealing and insulating the "envelope" of your home — your outer walls, ceiling, windows, doors, and floors — gives you the biggest bang for the buck to make your home more efficient. Properly air sealing cracks and openings in your home can significantly reduce heating and cooling costs, improve building durability, and create a healthier indoor environment.

Simply walking around during the winter and checking for drafts can help pinpoint many of these leaks, though make sure to check attics, basements, and crawl spaces for larger leaks. Caulking up windows, using weather strips on doors, and filling in gaps in attic insulation are all reasonably easy to do for the average homeowner.

What You need

For the best results, you should hire a contractor that is trained in air sealing. A trained professional will also be able to determine if your home could benefit from a bigger project like adding new insulation. 

If you decide to do it yourself, you will need different supplies depending on what work you are doing: 

For windows:

  • Caulk (a glue-like substance for sealing leaks), which can be found at any hardware store.
  • Storm windows can provide an extra level of sealing during the winter, especially for homes with older single-pane windows.
  • Plastic sheets can serve as an easier alternative when storm windows aren’t installed.

For doors:

  • Weather strips can be installed along the sides and top of doors leading outside to seal leaks without making the door hard to open.
  • A door sweep can be used at the bottom of the door.
  • Caulk can be used to seal leaks along the outside of the door frame if needed.

For attics:

  • Rolled fiberglass insulation for filling in or adding to existing insulation.
  • Expanding spray foam insulation for filling in closed areas and walls.
  • Other supplies as needed. See the guide linked below.

For basements:

  • Caulk to seal joints and other holes leading up into the house.
  • High-temperature caulk to seal cracks around the furnace flue.
  • Expanding spray foam insulation to seal larger areas.

If you want to do it yourself, the ENERGY STAR program provides a good detailed guide.


  • Nicor Gas Home Energy Savings Program

    • Best For:

      Rebates for appliances or equipment, Hot deals, Holistic "Whole Home" Approach
    • Value:

      Discounted Home Energy Assessment and Incentives for Weatherization

    Nicor Gas and ComEd are now offering instant rebates up to $1200 for air sealing and attic insulation. The Home Energy Savings Program can help make your home more energy efficient, comfortable, and help cut down on energy waste.