What insulation does a house of your age have?
A house's age is a rough guide to its insulation: very old houses often have little or none, mid-century ones usually have a thin attic layer and empty walls, and newer ones have more but still leak air. Renovations and past upgrades change the picture, so confirm what you have by inspecting it.
Why does the build year matter?
Insulation requirements in Canadian codes have tightened over the decades, and construction methods changed along with them. The year gives a starting guess, which an inspection then confirms or corrects. Owners also renovate: a 1960 house might have had its attic topped up twice and its walls blown with fibre, or it might never have been touched. Treat the era descriptions below as likelihoods, not facts about your house, and look inside the attic, the rim joist and an outlet cover or a small hole in a wall to see what is there.
What is typical before about 1950?
Many early houses were built with little or no insulation in the walls, and the attic may hold sawdust, wood shavings or a thin layer of loose material. Framing often has open paths for air to move through the walls and up to the roof. Solid masonry houses have no cavity at all. Old wiring and insulation types need care. Loose vermiculite may contain asbestos and should not be disturbed, as covered in replacing attic insulation. The biggest returns here come from sealing and insulating the attic and rim joist, then dealing with walls, using the sequence in insulation upgrade priorities.
What is typical from the 1950s to the 1970s?
Postwar houses often have some insulation in the attic and sometimes in the walls, although levels were modest by today's standards and may have settled. Basements were seldom insulated. During the 1970s, when energy prices jumped, owners and builders began adding insulation, and one foam product used in wall cavities, urea-formaldehyde foam, was banned in Canada in 1980 after health concerns. If you suspect it, get advice from your provincial authority. This era usually gains most from attic insulation, air sealing and basement insulation.
What is typical from the 1980s to the 2000s?
Houses built after the energy crises usually have insulated walls, a polyethylene vapour layer and better attics, and the first airtight and R-2000 houses appeared in this period, as described in the R-2000 explainer. Stud walls were typically filled with batts, so thermal bridging through framing is still a loss, discussed in thermal bridging. Attic depth may now fall short of current recommendations, and rim joists and attic hatches are common leak points. Check windows too, since early double glazing lacks coatings.
What about houses built in the last two decades?
Recent houses meet stricter codes, have tighter envelopes and often include mechanical ventilation. Gains are smaller but still possible: attic top-ups, sealing missed gaps and improving windows or basement walls. Labels such as ENERGY STAR and the EnerGuide rating help compare houses, see EnerGuide rating explained. An energy adviser can test the airtightness and scan for missing insulation with a thermal camera through a home energy audit. Whatever the age, a single overview of materials and choices is in the home insulation guide. Rules and incentives change, so check the Government of Canada energy-efficiency pages and your province before spending.
Quick answers
How can I tell if my walls are insulated?
Remove an outlet cover and look around the box with a light, or have an energy adviser use a thermal camera or small test hole. Do not rely on the build year alone.
Is old insulation still good?
Dry, clean material can keep working for decades, though it may be thin by current standards. Wet, mouldy or contaminated material needs attention.
Should I insulate walls in an older house?
It can help comfort and bills, but it is costly and needs moisture planning. Attic, air sealing and basement work usually come first.