Insulation Calculator

Ontario's building code (OBC SB-12) sets minimum insulation requirements based on climate zones. Most of Southern Ontario, including the GTA, falls in Climate Zone 6, which requires R-60 in attics, R-24 for exterior walls, and R-20 for basement walls. Meeting these minimums is mandatory for new construction and many renovation permits.

The right insulation type depends on your application. Closed-cell spray foam offers the highest R-value per inch (R-6.5) and doubles as an air and vapour barrier, making it ideal for basement walls and rim joists. Open-cell spray foam (R-3.7/inch) is more affordable and excellent for attics and interior walls. Fiberglass batts remain the most budget-friendly option for standard wall cavities.

Professional installation is recommended for spray foam insulation, as it requires specialized equipment and training. Fiberglass batts and mineral wool can be a viable DIY option for experienced homeowners, though professional installation ensures proper coverage and avoids compression that reduces R-value.