Asbestos / vermiculite / UFFI (pre-1990)
Asbestos-containing materials, Zonolite vermiculite, and (1975–1978) UFFI insulation used in older construction.
Asbestos use ran into the 1980s; a pre-1990 build has a reasonable chance of containing these materials.
What it means for you: Safe if undisturbed, but provincial law requires a hazmat survey before any renovation/expansion/demolition, adding cost and time.
Check: Hazardous-materials survey; a Salvage/Abatement or demolition permit on record indicates it was handled.