Windows & Doors

Learn how to spot energy leaks, fix drafts, and decide when to replace your windows and doors.

Windows & Doors
On this page
  1. The Truth About Energy Loss
  2. Finding the Leaks
  3. Repair or Replace
  4. Weatherstripping and Caulking
  5. Window Replacement Costs
  6. Upgrading Your Exterior Doors
  7. Dealing with Condensation

The Truth About Energy Loss

Windows and doors are big holes in your walls. They let heat escape in the winter and sneak inside during the summer. You might think you need brand new windows to lower your energy bills. That is not always true. Often, a cheap tube of caulk saves more money than a huge renovation. Your HVAC system works hard to keep you comfortable. Do not let that conditioned air leak outside.

Finding the Leaks

You cannot fix a draft if you cannot find it. Wait for a windy day. Hold a lit stick of incense or a candle near the edges of your windows and doors. If the smoke blows sideways, you have a leak.

Testing a window for air leaks with incense.
Testing a window for air leaks with incense.

You can also wait until dark. Have a helper stand outside with a bright flashlight. Turn off the lights inside and look for light shining through the cracks around your doors. Anywhere light gets in, air gets in too.

Repair or Replace

How do you know if a window is dead? Some problems are easy to fix. Others mean the window is ruined. A broken glass seal or a rotting frame cannot be saved with caulk.

ProblemActionEstimated Cost
Drafty edgesCaulk or weatherstrip$10 to $30
Cracked glass paneReplace glass only$150 to $300
Fog between panesReplace glass unit$200 to $400
Rotting wood frameFull replacement$600 to $1,200

Keep in mind that these costs are just estimates. Prices vary heavily by your region, the scope of the work, and the age of your home.

Weatherstripping and Caulking

Caulk seals gaps between the window frame and the wall. Weatherstripping seals the moving parts. You need both to stop drafts. Remove old peeling caulk before you apply new stuff. Use a good exterior grade silicone caulk on the outside of your house.

Applying fresh caulk to an exterior window frame.
Applying fresh caulk to an exterior window frame.

For moving sashes, stick on some foam or rubber weatherstripping. This takes a few hours and costs very little. If you notice soft wood around the frame while you work, you might have bigger issues with your exterior siding.

Pro Tip: Buy a dripless caulking gun. It stops pushing caulk the second you let go of the trigger. This keeps your lines clean and saves you from a sticky mess.

Window Replacement Costs

Sometimes you just need new windows. Single pane windows are terribly inefficient. If your house still has them, upgrading makes a huge difference. Vinyl windows are cheap and need zero maintenance. Wood windows look beautiful but cost more and need paint. Fiberglass sits in the middle.

If you hire someone to install them, check their references. Read our guide on hiring contractors to protect yourself from bad work.

Vinyl$400 to $800
Fiberglass$600 to $1,000
Wood$800 to $1,500
Custom$1,200 to $2,500

Remember that these are ballpark numbers per window. Prices change based on your region, project scope, and home age.

Upgrading Your Exterior Doors

Your front door takes a beating from the sun and rain. Wood doors warp and swell. If your door sticks in the summer but shows gaps in the winter, the wood is moving. Fiberglass doors are a great upgrade. They look like wood but never warp. Steel doors are very secure and cheap, but they can dent and rust. A solid door also helps boost your home security.

A door sweep blocks wind and bugs at the threshold.
A door sweep blocks wind and bugs at the threshold.

Do not forget the door sweep. This is the rubber strip at the very bottom of the door. It drags on the threshold to block wind and bugs. Sweeps wear out every few years. You can unscrew the old one and slide a new one into place in five minutes.

Dealing with Condensation

Water droplets on your glass can be tricky to diagnose. If the water is on the inside of the room, your house is too humid. Turn on your bathroom fans. If the water is trapped between two pieces of glass, the window seal is broken. The insulating gas leaked out.

Fog between the glass panes means the window seal has failed.
Fog between the glass panes means the window seal has failed.

You cannot fix a broken seal. You have to replace the glass unit or the whole window.

Warning: Ignore rotting window sills at your own risk. Water trapped in the wood will invite termites and carpenter ants into your walls.

If you see lots of bugs near a rotting frame, you might need pest control to clear them out before you put a new window in.

Frequently asked

How do I know if my windows need to be replaced?

Look for rotting wood frames, glass that is foggy on the inside, or windows that refuse to open. If you just feel a draft, you probably only need new weatherstripping.

Is it worth upgrading from double pane to triple pane windows?

Usually no. Triple pane windows cost much more but only offer a tiny boost in energy savings. Stick to high quality double pane windows unless you live in an extremely cold climate.

Can I replace just the glass instead of the whole window?

Yes. If your window frame is solid but the glass is cracked or foggy, a glass repair company can swap out just the glass unit. This saves you a lot of money.

Why does my front door stick in the summer?

Wood doors absorb humidity from the air and swell up. When the air dries out in the winter, the wood shrinks back down. You can sand the edges or switch to a fiberglass door to stop this.

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