Building Envelope

Insulation – Walls

Walls can account for up to 20 per cent of heat loss in your home. In addition to heat loss through your walls, cracks and penetrations may allow uncontrolled air leakage into and out of your home.

Insulation is designed to prevent heat or sound from being transmitted from one area to another. It works by trapping pockets of air and slowing down the in/out process. The type of insulation you need will depend on the type of walls (i.e. solid, concrete block, frame) in your home. You can install one or more of the following: blown-in, rigid board, batt/blanket and spray foam insulation.

What to Look For

  • Insulation is rated by its R-value. “R” is the resistance and the higher an insulation’s R-value, the more efficiently it resists the transfer of heat from one area to another.
  • Different types of insulation have different R-values. You can use more than one type to achieve a higher overall R-value rating.

Things to Consider

  • Cold floors and walls in the winter and mould growth are signs of a poorly insulated home.
  • Ensure your project meets the minimum R-value required to be eligible for rebates, if available.
  • Hire a professional. Improper installation can lower the R-value of the material, and there are health and safety considerations as well.
  • Consider getting an Energy Efficiency Home Evaluation to help you understand how your home uses energy and identify all improvement opportunities.
  • Check with your municipality, utility or retailer to see if rebates are available.


$150 to $3,000, plus installation.

Source: Natural Resources Canada