Draft Sealing
Sealing drafts without a renovation
Air leakage is the uncontrolled movement of air through gaps in a building. Unlike a deliberately opened window, these leaks run constantly and pull heated air out while drawing cold air in. Sealing them is one of the lowest-cost improvements a household can make, and it often produces a noticeable difference in comfort near exterior walls.
Find the leaks first
On a cold, windy day, leaks are easier to feel by hand around door and window edges, electrical outlets on exterior walls, and the attic hatch. For a complete picture, a registered energy advisor can run a blower-door test, which depressurises the house and reveals leaks that are hard to detect by touch.
The usual suspects
Exterior doors
Worn weatherstripping and gaps under the door are common. Replacing the weatherstripping and fitting a door sweep or new threshold closes the most obvious path.
Windows
Fixed window frames can be caulked where the frame meets the wall. Operable sashes rely on their own weatherstripping, which can be replaced when it hardens or compresses.
Penetrations and the attic hatch
Plumbing and wiring that pass through exterior walls or the ceiling leave gaps. The attic hatch is frequently overlooked — weatherstripping its edges and insulating the back of the panel both help.
A simple order of work
- Walk the perimeter on a windy day and mark felt leaks.
- Weatherstrip and add sweeps to exterior doors.
- Caulk fixed window and door frames.
- Gasket the attic hatch and seal obvious ceiling penetrations.
- Consider a blower-door test to confirm the result.
How it connects
Air sealing pairs directly with insulation basics: a sealed, well-insulated envelope holds heat far better than either measure alone. Once the building is tighter, the seasonal heating guide explains how to run the system efficiently.