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How to fix drafty windows: Get your windows to leak less heat

Window drafts are uncomfortable and annoying. Here’s what to do to stop them.

Window drafts are uncomfortable and annoying. Here’s what to do to stop them.

When cold temperatures hit, do you constantly feel chilly drafts near your windows?

Drafty windows are definitely uncomfortable, but they’re also a sure sign of energy waste in your home. And drafty windows can allow allergens and excess moisture into your house, which can cause respiratory issues.

While you might think that you need to replace your windows to solve the problem, that isn’t always the case. (And that’s good news because installing new windows can be an expensive fix.) In this article, you’ll learn:

What causes drafty windows? 

Winter winds and older windows might seem like the source of your drafty house problems, but air leaks and poor insulation are usually the primary culprit.

Air leaks are the open gaps, cracks, and seams in your home that can cause drafts, moisture issues, and heat escape. Every home has air leaks—they form as houses settle and shift over time (this happens even in new construction). 

But these gaps and air leaks throughout your home are small. How do they cause so many big drafts? 

Here’s how: Cold air is actively sucked into your home through those gaps.

You can think of this effect like a giant vacuum. As heat rises up through the house and escapes out through the attic (usually due to inadequate insulation), it leaves a vacuum. And since that vacuum must be filled, cold air from outside rushes in through all the tiny holes in your house to fill it, causing your windows—and the rest of your home—to feel drafty and uncomfortable.

Airflow and home ventilation problems cause heat escape

And that air leak problem isn’t limited to your windows. Air gaps are also common around exterior doors, plumbing fixtures, your fireplace, cables, light fixtures, the foundation of your house, or in your attic.

How do I stop cold air from coming through my windows? 4 alternatives to installing new windows

Most people assume that if they have drafty windows they need to install new windows to resolve the problem. 

But getting your windows to leak less heat truly requires a whole home solution or approach. Here are four effective alternatives to installing new windows:

  1. Air sealing your windows
  2. Insulating old windows
  3. Whole-house insulation and air sealing (this solves the drafty home problem for good!)
  4. Installing temporary fixes to decrease drafts today

Wait—why shouldn’t I buy new windows?

Here’s why new windows won’t solve the problem: They aren’t the real reason you’re experiencing drafts in your home. 

Even if your goal is to install new windows in your home one day, you must fix the primary issues that are causing heat loss in your house to truly benefit from an expensive window upgrade.

Unwanted airflow—created by that vacuum effect we keep talking about—is the primary reason your windows are drafty and leaking heat. 

This is a whole-house problem, but thankfully, there is a whole-house solution: To permanently stop unwanted airflow in your home, you’ll need professional air sealing and insulation

(And Sealed can help you get the work done with zero upfront cost. Learn how.

How to fix drafty windows in a rental property—temporary window fixes

But before we jump into permanent solutions, we need to address the elephant in the room: What if you’re in a rental or are a homeowner who needs a very quick temporary fix right now to make your home more comfortable? 

If you need to fix drafty windows today, there are a few temporary fixes you can use in the short term to help stop window drafts.

  1. Hang curtains and blinds. Window blinds and curtains aren’t just for home decor; they can serve as extra insulation around windows. Both curtains and blinds can help temporarily reduce drafts that are coming through the seams and gaps around your installed windows. 
  2. Use homemade draft stoppers. Making a draft snake for gaps around windows and exterior doors, or hanging up a quilt to block airflow, can help reduce icy-cold air from getting in through leaks near windows and doors. 
  3. Upgrade your weather-stripping. If the weather-stripping around your windows and doors is looking worse for the wear, installing some inexpensive window and door weather stripping can help with some draft reduction.

Now let’s dive into the long-term and permanent fixes below.

Insulating old windows: Here’s how to get windows to leak less heat

What it is: Insulating old windows is a better option than some temporary drafty window fixes, but you’re still only covering up one symptom of your bigger problem: unwanted airflow and heat loss.

Is it effective to insulate old windows? Sometimes. Insulating your windows is a longer-term fix, but it’s not a permanent fix for drafty windows. Insulating your current windows can help them leak less heat in the short term. (Remember drafty windows are part of a whole-house problem, not simply an old window problem. This issue can be permanently fixed through professional air sealing and insulation.) 

How to insulate a drafty window: In addition to using blinds, curtains, and draft stoppers, you can install custom-fitted interior storm windows. These interior window add-ons can provide an extra layer of insulation for single-paned windows without blocking any views, or a window shrink-film kit is a budget option. But both these options won’t stop air leaks from gaps along the edges of your window where it’s inset into the wall of your home.

How insulating your house properly can help your windows leak less heat: When your home is insulated correctly, it’s a lot harder (or impossible!) for heat to escape through the roof of your home—which shuts down the “vacuum cycle” that pulls in cold air through the gaps around your windows.

Not sure whether your old insulation is doing the job? Keep in mind that home insulation wears down over time. When your insulation wears down, it reduces the thermal boundary between your house and outside temperatures and increases the risk of heat escape. (If you haven’t had your insulation checked out by a professional in 10 years, it’s probably time.)

The permanent fix: Have your home insulated by people who know what they’re doing.  Working with a professional home performance contractor can help you identify the areas your home is leaking heat through insufficient insulation. They’ll select the right insulation for your house based on r-value as well as what insulation you already have. That way, you’re treating the problem with the right solution and reducing or eliminating drafts for good.

How to seal old windows to stop cold air from coming through for good

What it is: Air sealing windows is the act of carefully detecting air leaks and closing them up with caulk, insulation, or other heat escape barriers. Sealing your old windows is just one step in the process of getting rid of drafts in your house once and for all.

How to seal old windows: The steps to window sealing are deceptively simple. First, detect the window seams and gaps, both inside and on the exterior of your home, and then add a line of caulk to close those gaps and actively reduce unwanted airflow for good. Make sure to use the correct type of caulk for sealing windows if you plan to do it yourself. 

If you have wood windows or windows with older glass panes, you may need to reglaze your windows as well. Similar to caulk, window glazing compound is a fairly inexpensive product, but much like home air sealing, it’s difficult, technical work to reglaze windows. 

But here’s the thing: Make sure you know what you’re doing before you start. There are specific parts of windows (called weep holes) that are purposely there to allow moisture to escape—don’t block these, or you could cause permanent damage to your windows. You’ll also want to avoid caulking over any parts of a window that will keep it from working correctly.

In short? Unless you’re willing to risk window damage or over-sealing, air sealing isn’t a great DIY project. For the best results, you’ll want to contact the professionals. If your home is eligible (find out here in 2 minutes), you could get whole-home air sealing (including your windows!) and insulation upgrades at no upfront cost. 

Why you need a professional to air seal your whole house: Air sealing your house and windows is a science, and home performance contractors who do the work are professionally trained. Sealing your windows incorrectly could cause damage, so it’s a job best left to the pros.

And even if you are careful to seal your windows correctly yourself, there are still open seams, gaps, and cracks throughout your home that help cause drafts. So unfortunately, even with new windows (or newly sealed windows), your home still won’t be draft-free after all that effort. 

The permanent fix: Professionally air sealing your whole home is the way to stop drafts permanently. If you only seal your windows, you won’t solve the underlying problem.

When you permanently fix drafty windows through professional air sealing and insulation, you’ll also reduce your energy usage, increase your home’s air quality, and make your home feel amazing year-round. 

Wondering how to fix drafty windows the permanent way? Get expert advice and solutions with Sealed

Fixing drafty windows can be a challenging project—one that can leave you with continued unwanted airflow if your home hasn’t been professionally sealed and insulated. 

But depending on where you live, you can get professional home insulation and air sealing (including sealing and insulating your old windows!) at no upfront cost.

You’ll pay for the work done at a rate based on the energy you save. And we stand by our work, too. If you don’t save energy, we don’t get paid.



January 25, 2022