Question: There’s a draft coming from our office window — how badly does this affect our energy bill?

Answer: Drafts always affect your energy bill. Heating and cooling costs add up quickly — and this is why good insulation is important. Ditch that draft and we’ll help you seal in the savings.


The thing about windows is at some point, they will leak. Not only will this result in a more expensive energy bill — but it can lead to big things like water damage and mold.

The good news is if you identify the leak early, it’s not too difficult to fix it. This is how you can fix a window leak and optimize your building to make it most energy efficient.

Investigate the window leak

Check the window out from the exterior and look for things like peeled or damaged caulk. Just to be clear, caulking is a protective sealing agent that protects the edge of windows from mildew growth, moisture and drafts.

It’s important to also check the gasket between the window frame and the glass. If it’s loose and no longer watertight, this is also something that will need to be fixed. A clear caulking will be necessary for this particular task for aesthetic purposes.

If you come across damaged wood — damp or decayed, this means things may have escalated and you should call a contractor to investigate the situation further in case of any serious water damage.

Fixing the window leak

Caulking can be purchased from places like Rona or any home hardware store really.  You will need to also purchase a caulking gun for application and grabbing a caulking scraper is also a good idea.

Once you have identified the leak, removed all the peeled or damaged old caulk and are ready to re-apply new caulk — the repair is simple.

Caulk it; have a little dish with water and dish soap handy so you can use your fingers to spread the caulking without it sticking to your hands. Once completed, you should let the caulk cure overnight before you paint it.

If your issue is a leaky window frame, you’ll need to pry off the trim and check out the space between the glass and frame. Ideally, it will be easily corrected with some caulk. However, if the situation has escalated and there’s some rotten wood, an additional step is necessary and you’ll have to chip away at it and then fill that void with some epoxy wood filler. Once you nail back the window, you’ll have to complete the task by caulking all the edges with waterproof caulk.

Check your windows at least twice a year anyway

Always take precautions to avoid a draft. A well insulated, sealed up building is an energy efficient one. This will help keep heating and cooling under control — keeping warm air from escaping when it’s cold outside.

Even the tiniest crack can lead to wasted energy — one as small as 1/16th of an inch can let in as much cold air into your building as leaving your window three inches open. Maintenance is important and beneficial to your energy bill.

For businesses that are as energy efficient as they can be, there are incentives and rebates.


Image credit: fruitnveggies