Building Shell

Imagine that your home is a boat or hot air balloon. Any leak you find must be plugged. It’s really the same with houses. As warm air migrates to the coldest areas, (ex. outside air) it seeps through walls, roofs, cracks, doors and windows, so it is important to know how to prevent heat loss.


Although it is generally unprofitable to reinsulate an existing building, major renovation can provide a good opportunity to enhance the insulation. Poorly insulated but accessible roof spaces are one example.


Make sure door and window frames are well caulked and install weather stripping. Caulk the junction between the outside walls and the foundation. Air intake is greatest at this location in most Canadian homes.

Window liner

Add a window liner to basement windows as well as to windows that are not often used. A window liner is a plastic film that can be installed and then shrunk with a hair dryer.

Replace your windows

If any of your windows are single-glazed, it would be a good idea to replace them with double or triple-glazed windows.

  • Do not confuse double glazing with sealed double-glazed windows. The latter are made up of two panes separated by very dry air or a low conductivity gas that is thoroughly sealed by a caulking system and locked into the same frame. These windows also eliminate condensation between panes of glass.
  • Sealed double glazing will cost you more but will be twice as efficient as regular double glazing. Sealed triple glazing will be four times more efficient than regular double glazing.
  • A low transmission pane is coated with a thin, almost invisible film, which reduces heat loss, reflects outside heat in the summer and blocks UV rays that make the color of your drapes, carpets and furniture fade. The best type of pane currently available includes a sealed-in gas such as argon.

Grants available for installing windows    Learn more

Replace your doors

Replace your hollow outside doors with insulated doors. Touch the inside of your door. If the surface is colder than that of your inside walls, replace it with a better insulated door.

Clean your sliding doors

Clean the tracks of your sliding doors. Dust and debris of all kinds can force your doors out of alignment and let outside air in.