DIY Home Improvement: Insulating Your Windows

Hi there! Max here, with the first installment of my DIY home improvement tip series! With all of the chilly weather we’ve been experiencing, I wanted to share some helpful tips to keep the cold out and the warmth inside your home. The Energy Information Administration (EIA) estimates that as much as one third of the average home’s heat loss occurs through windows and doors. Since replacing windows aren’t an option for everyone, the following tips can help reduce heat loss, drafts, and make your home more comfortable this winter.

Window Exteriors

If you notice cracking in your exterior caulking, you may also be feeling drafts inside your home. The costs of replacing one of your main defenses against heat loss will be offset through lower utility costs within in a year, according to the U.S. Department of Energy. For best results, wait for clear skies and temperatures above 45 degrees Fahrenheit.

Step 1:

Scrape edges of windows clean of any old caulking or peeling paint and wipe clean with a damp rag.

Step 2:

After the surface has dried, load exterior-grade silicone caulking into your no-drip gun and apply between the frame and siding all the way around the window. Make sure to hold the gun at 45 degrees in order to get as deep as possible into the cracks around the window frame. If any caulk oozes out of the crack, just push it in gently with a putty knife. Allow the caulk to cure overnight to provide optimal protection from the outside elements.

Window Interiors

There are a few different ways you can improve the insulation on the interior of your windows. Have you noticed that the weather stripping is worn or crumbling? It can be attached by a simple adhesive-backed strip or with nails or screws.

Step 1:

If nailed or screwed, remove with a claw hammer or drill before pulling back the strip. Once the weather-stripping has been removed, wipe down inside of window with a household cleaner and paper towel.

Step 2:

Be mindful when you’re choosing replacement weather-stripping by closely considering the pros and cons of each material. Bob Vila suggests adhesive-backed foam or tubular gasket stripping, both of which are more reliable than felt and provide 3-5 years of protection. Measure your sash (the part of the window that moves to open and close), then cut the weather-stripping of your choice to the correct length. Starting on one end, peel of any adhesive backing, then carefully press the weather-stripping into place, making your way carefully to the other end.

Step 3:

With the new weather-stripping in place, you’ll want to add an extra layer of protection with an insulating window film. This window covering helps your home retain heat, reflects heat, and blocks UV rays. Cheap versions of this protective covering are less attractive and can hinder visibility. suggests Low-E window films, which are coated with a very thin metallic coating that helps to reduce infrared heat. Installation instructions vary by type of film, so make sure to read carefully and to always clean the window(pane) carefully to ensure no dust or lint gets trapped during application.

Step 4:

In addition to the above suggestions, hanging thick, full length curtains can be a low-cost defense against heat loss. To maximize results, make sure to hang the rods above and extending past each window on both sides. Also, using blackout or lined curtains will get you better results than sheer, thin options.

All of these options are a fraction of the cost of replacing windows. Replacing windows can be costly, or for a rental tenant, not worth the investment. Try using any or all of the above tips to improve your energy bill and keep warm until Spring!


  1. Steffani Cameron, “How to: Insulate Windows,” Weblog Bob Vila, accessed January 22, 2018,
  2. Jen Carter, “Improving the Energy Efficiency of Existing Windows,” Weblog, entry posted October 15, 2008, accessed January 22, 2018,