Building Envelope

Insulation – Basement

A basement can account for about 20 per cent of a home’s total heat loss. Adding insulation to your basement is important whether or not space will be finished. For optimal energy efficiency, your home should be properly insulated from the roof down to its foundation.

Much like your attic, basements need to be sealed, insulated, and ventilated. Proper insulation not only reduces heating and cooling costs but also improves comfort. The materials used to insulate your basement will depend on your foundation and whether you need to insulate inside or outside of your home.

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, and they can be combined to achieve a higher overall R-value rating.
  • The goal is to achieve a minimum of R12 for 100% basement.

Things to Consider

  • Before planning your renovation, assess your basement. Check for water leaks, dampness and determine if you need interior or exterior insulation.
  • Do not insulate the interior of a basement with leaks or dampness problems.
  • Ensure your project meets the minimum R-value needed to receive any available rebates.
  • Before you start, get a home energy evaluation and check with your municipality, utility or retailer to see if rebates are available.


$6,500 to $18,000

Source: Natural Resources Canada