Sealing & Insulation Cut Home Heating & Cooling Bills 15%

This blog was authored by Davis Conger, an NRDC intern from George Washington University.

With the official start of winter around the corner, you can save a nice chunk of change on your energy bills by simply sealing household air leaks and ensuring proper attic insulation levels. It will make your home more comfortable and you won’t be wasting energy and money.

In fact, U.S. households can save 15 percent of annual heating & cooling costs, on average, with simple fixes like installing weather stripping on doors or adding caulk around windows. Larger projects like adding insulation to your attic, or installing more energy efficient windows and doors, can help you save even more. Check out this chart to estimate the potential energy savings from improvements made to the typical home in your climate zone to get an idea of just how much you might be able to save.

Small Holes Can Be Big


Sealing tiny holes can make a big difference. In fact, if you add up all the small holes in a typical home, they would be equivalent to having one window open all the time! As temperatures begin to drop (or rise in the spring), it’s important to ensure that your home is properly sealed and you’re not throwing energy dollars out the window. (You’ll also be doing your part to fight climate change because when we use less energy, it reduces the need for power plants to burn fossil fuels to generate it—and avoids the associated carbon pollution that harms our health and the environment.)

First, check to see whether heat (or cooling in the summer) could be escaping from your home through small holes. Check out the Department of Energy’s list of potential cracks or gaps—including doors and window frames, electrical outlets, fireplace dampers, wall or window-mounted air conditioners, mail slots—or this ENERGY STAR illustration to learn about common air leaks.

Help from the Pros

Having trouble locating cracks or gaps? You’re not alone—often air leakage comes from cracks you may not be able to easily see, or places like your attic that may not be easily accessible. The best way to get a full understanding of what’s happening in your home is with an energy audit. A professional energy auditor will come to your home and perform diagnostic testing, including a blower door test, to determine exactly where you are wasting energy. The auditor will provide you with a full customized report, which will include ways to make your home more efficient and more comfortable. Check with your utility company—many power companies offer rebates or discounts for energy audits, as well as for adding insulation to your home, and other energy efficiency upgrades.

Do It Yourself

If you want to go the DIY route to stop heating (and cooling) from escaping from your home, use caulk to seal cracks around doors and window frames, as well as leaks where plumbing, ducting and wiring comes through walls and ceilings. Install weather-stripping on things that move, like doors and windows. Keep the flue closed when you’re not using the fireplace.

But the biggest savings will come from sealing big holes hidden in the attic (and if you have one, the basement or crawlspace), then adding insulation up to the recommended levels.

Rule Your Attic

If the attic insulation is higher than the floor joists, that’s a good sign. You can measure your attic’s insulation levels with a ruler. An average home in southern climates typically needs 13 to 14 inches of insulation and homes in northern climates may need around 16 to 18 inches. Check this link for more details on attic and basement insulation. But before beginning these steps, be sure to don safety glasses, gloves, and a dust mask/protective face gear. And if the insulation has small, grey pea-sized materials in it, it might be vermiculite insulation, which can contain asbestos. Contact the local health department to have it tested before going further.



Through its “Rule Your Attic!” consumer outreach promotion, ENERGY STAR offers several Do-It-Yourself sealing and insulation projects, along with the supplies and resources needed. Links are also provided to qualified contractors who can help and for information on how to check with your local utility to see if it offers rebates for air sealing and insulation.

Sealing your home and improving insulation are investments that extend beyond saving energy and money. As ENERGY STAR notes, additional benefits include:

  • More control over indoor humidity levels
  • Decreased noise pollution from outdoors
  • Reduced potential for ice dams to leak into your home and damage walls, floors, ceilings, etc.
  • Blockage of pests, pollen, and dust

The how-to videos, graphics, and individual projects provided by ENERGY STAR can help you better seal your home, increase energy efficiency, cut your energy bills, and reduce your household’s carbon footprint. And the impact will be felt year-round.

Note: The federal ENERGY STAR program is at risk. President Trump proposed eliminating it altogether and the U.S. House has proposed significant budget cuts, as well as altering the program in ways that could compromise it. To learn more, see this blog.

About the Authors

Lauren Urbanek

Deputy Director, Clean Buildings, Climate & Clean Energy Program

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