How to stop your house’s expensive drafts — and save the planet

At the risk of sounding like a piece of circa-2007 clickbait, there is one neat trick homeowners can deploy to shrink their carbon footprint. It’ll make your house more comfortable, save money in the long run, and the government might help pay for it.

It’s “weatherization” — sealing up your home so you don’t waste energy on heating and cooling that is lost to the outside world.

Weatherization comes in many forms, but the easiest is closing up the cracks around windows and doors. You can first identify leakage points by turning on your kitchen and bathroom exhaust fans, creating a slight pressure differential between indoors and outdoors, then holding up a lit incense stick to potential problem areas. If the smoke wavers or blows in one direction, there's a draft that needs fixing. Use weather-stripping to insulate windows and install a sweep to the bottom of exterior doors. You can also place a draft stopper — a cylindrical pillow you can get for less than $15 at a hardware store — on windowsills and door thresholds.

According to the Energy Department, 25% to 30% of household heating and cooling is lost through windows. Just put your hand up to a pane on a winter day — feel how cold it is? That’s energy wasted. You can counter this by installing blinds or drapes; one Cornell University analysis found that a simple roller shade can reduce heat loss through a window by 24% to 31%. In summertime, glass treatments that block certain wavelengths of light can stop heat seeping into the home.

A somewhat more expensive option is to replace your windows. Look for double-, triple- or even quadruple-glazed windows; the more panes of glass the window has, the less heat it will transfer. Even fancier windows will include argon gas — a powerful insulator — between the panes.

When shopping, look for performance labels from the National Fenestration Rating Council. A window’s “U-factor” indicates how well it keeps heat from escaping, while the “solar heat gain coefficient” measures how well it prevents the sun’s warmth from coming in; low scores on both metrics indicate a well-insulated window.

If you plan to renovate your house, then it's a good time to think about sealing up crawl spaces, insulating ducts and repairing the heating and cooling system. The Energy Department has a helpful guide to adding insulation to existing buildings, and most contractors can talk through the best option for your home.

Even if you're not able to do a complete renovation, smaller measures such as putting a thick carpet on the floor of a room over an unheated garage or installing a radiant barrier in an attic that traps summer heat can make a difference.

Because weatherization can pose some hefty upfront costs, there are quite a few government programs to help homeowners pay for it. The Energy Department’s Weatherization Assistance Program, which is administered through states and tribes, will pay for upgrades to homes of people who can’t afford them. Weatherization is especially valuable for low-income households, which typically spend more than 16% of their annual income on energy bills (compared to 3.5% for other households). The Energy Department estimates that the program cuts energy expenses for these households by 35%.

But if you plan to live in your home for more than 10 years, the measures eventually will pay for themselves. A 2015 study by the Oak Ridge National Laboratory found that the Weatherization Assistance Program delivered $1.40 in energy savings for every dollar invested. When health and safety benefits were wrapped in, the return on each dollar invested increased to more than $4.

“Choosing to do the weatherization was the easiest part of the remodeling process,” said Erich Valo, a photographer and father of two in Oakland, Calif., who implemented a slew of energy efficiency measures when he remodeled his century-old house in 2019. By installing triple-glazed windows and improving insulation, he cut his winter gas bill by almost 60%.

His calculations suggest that the savings will exceed the cost of the improvements within 15 years. "But even if we sold the house and didn't get to reap all the investments, we'd know the next person would also be using less fuel," he said.

The carbon reductions from weatherization measures depend on how you heat and cool your home. Valo’s house is heated with natural gas, which generates 117 pounds of carbon dioxide per million British Thermal Units (a measurement of heat). That means his efficiency measures are saving more than 1,500 pounds of carbon dioxide every winter — the equivalent of canceling a road trip from Washington, D.C., to Denver.

It's a bit more complicated to calculate carbon savings from weatherizing homes that are heated electrically, or use air-conditioning in the summer, because those numbers depend on how your electricity is produced. But even if your energy comes entirely from solar or another renewable source, improving efficiency can help take pressure off the grid — something that will become increasingly important as more people purchase electric vehicles and appliances.

People often say they feel powerless in the face of the scale of the climate crisis. That’s fair: Humanity produced about 34 billion tons of carbon dioxide equivalent in 2020, a figure that makes Valo’s 1,500 pounds of savings seem a bit puny. The sweeping social and economic transformation that scientists say is needed to attack the problem will require a global effort.

But individual actions can still be meaningful, especially if they are followed up with advocacy. As climate scientist Daniel Swain of UCLA explained: The physics of the greenhouse effect mean that climate effects such as wildfires and hurricanes become exponentially worse with each incremental increase in global temperatures. That means every pound of CO2 cut — every bit of warming avoided — helps secure a safer future.

No action, however small, is pointless.

And if each person who pursues weatherization convinces two friends to do the same, then the effects of their action also grow exponentially. Valo’s 1,500 pounds of carbon savings could become 3,000, then 6,000. If all 139 million households in the United States used efficiency measures to cut their heating and cooling costs by a third, the country would save almost 150 million tons of carbon dioxide annually.