How Saint John is built
- Before 1961 34%
- 1961–1990 44%
- 1991–2000 9%
- 2001 or later 13%
What inspections find in Saint John attics
Of Saint John's 19,705 houses (single-detached, semi-detached, row houses and duplexes), 34% were built before 1961 and 78% before 1991, according to the 2021 Census. Attics in older houses commonly have a fraction of today's recommended insulation, and top-ups done over the years often buried air leaks instead of sealing them first.
Saint John gets about 4,580 heating degree-days a year, a measure of how much heating its climate needs, and its winter design temperature, the cold day heating systems are sized for, is −22.5°C. Those figures come from the climate data for Saint John in HOT2000, the home-energy software Natural Resources Canada (NRCan) gives energy advisors. That's about 16% more heating demand than the middle of the 70 cities we cover. The colder the climate, the faster added attic insulation pays for itself.
Vermiculite. Loose, pebbly, grey-brown or silver-gold insulation may contain asbestos. Health Canada's advice is not to disturb it; have it sampled before any attic work. Asbestos and vermiculite testing in Saint John
The right order for the work
- Seal the air leaks first: top plates, pot lights, plumbing stacks, the hatch.
- Fix ventilation baffles so new insulation doesn't block soffit vents.
- Then top up the insulation. Burying unsealed leaks under new insulation wastes much of the benefit.
Atlantic Canada Maritimes and Newfoundland
What this means in Saint John’s climate
Damp, windy, icy winters and costly oil: switch to heat pumps, seal, test for radon.
Atlantic winters are wet, windy and icy rather than extremely cold, and summers are mild. Heating oil is still common and its price rose sharply in 2026, while heat pumps already heat many homes. An EnerGuide evaluation here should plan the move off oil, seal wind-driven leaks, fix moisture before insulating, and include a radon test.
- Seal wind-driven leaks and the attic. Wind pushes cold air through gaps, and heavy, wet snow with frequent freezing rain makes a leaky attic prone to ice dams. Ask: Ask for a blower door test on a calm day, with a thermal scan to find wind-driven leaks.
What else homes in Saint John need →
Sources for this climate guide · checked October 26, 2026
- National Building Code of Canada 2020, climate data (NRC)
- Canadian Climate Normals 1991–2020 (ECCC)
- Keeping the Heat In (NRCan)
- Heat pumps, Canada Greener Homes (NRCan)
- Heat pump basics (NRCan)
- Heating and Cooling With a Heat Pump (NRCan)
- Primary heating systems by household, Table 38-10-0286-01 (Statistics Canada)
- Household heating oil prices, Table 18-10-0001-01 (Statistics Canada)
- Electricity price comparison, April 2025 (Hydro-Québec)
- Prevent oil tank spills (Government of Nova Scotia)
- Canada's top weather stories of 2019 (ECCC)
- Canada's top weather stories of 2022 (ECCC)
- Canada's top weather stories of 2023 (ECCC)
- 2024 Cross-Canada Survey of Radon Exposure
- Guide for Radon Measurements in Homes (Health Canada)
- Conditions for thermal scans, ASTM C1060 summary (Cx Associates)
- Canada's top weather stories of 2018 (ECCC)
- Canada's most impactful weather stories of 2024 (ECCC)
NRCan-licensed service organizations serving Saint John
A service organization is a company that Natural Resources Canada (NRCan) licenses to deliver EnerGuide evaluations; its registered energy advisors do the home visit. Every EnerGuide evaluation includes an attic inspection: insulation depth, air leaks and red flags such as vermiculite or knob-and-tube wiring.
- Enercheck Solutions
- Homesol Building Solutions
- RU-Green Energy Solutions
- ThermalWise Green Building Cooperative
Insulation programs in Saint John
Attic insulation inspection in Saint John: common questions
How much attic insulation should a Saint John house have?
Advisors commonly target around R-50 to R-60 in attics. Your EnerGuide report gives the recommendation for your house.
Can I top up the insulation myself?
Only after the air leaks are sealed and you've confirmed there is no vermiculite. The inspection tells you both.
Will more insulation stop ice dams?
Insulation helps, but ice dams are mostly caused by warm air leaking into the attic. Air sealing is the bigger fix.