Controlling air leakage is one of the cheapest – and most important – ways to make sure your home is as climate-friendly as possible. This topic goes hand-in-hand with Insulation. Without a good air and vapour barrier, your insulation will not be effective.

The amount of air that escapes the average house may surprise you. If all the cracks and holes were added together you would end up with a basketball-sized hole. This air leakage amounts to 25-40% of the average heat loss in winter and cool air loss in summer. (1) In fact, an older home may replace all its air once each hour. (2)

New homes

New homes will generally be built to much higher energy efficient standards than older existing homes, but improvements can often be made.

One suggestion is to hire an EnerGuide for New Houses advisor to evaluate your new home. This process includes analysis of your house plans and recommendations on how energy efficiency can be improved, including air leaks and sealing. (3)

Or you may want to choose a new house already being built to R-2000 or Passive House standards, which ensures it will reach high standards of air tightness.

Existing homes

Air can find escape routes throughout your house. Here’s how it often breaks down (4):

• 25% Basement and where the upper wood frame meets the foundation
• 20% Exterior electric outlets
• 13% Windows
• 13% Pipe and wire entrances
• 10% Vents
• 7% Baseboards, light fixtures, electrical outlets and attic hatches
• 6% Exterior doors
• 6% Fireplaces

You can detect air leaks by lighting two or three sticks of incense on a cold or windy day and checking suspected leakage spots. The smoke will alert you to air leaks by blowing away for strong leaks or being drawn in or puffed in one direction for more minor leaks. (5)

Then caulking, weather stripping and other air sealing materials are your tools to fix the problem. Ensure you take into consideration humidity, ventilation and air for combustion. (6)