Sounds like you are just a tenant. Hope you were using the rented space as per your rental agreement ON PAPER. And if so, zero worries for you I would think. For the Building owner, I hope he was renting all units out to others as per City or Township zoning. And then on top hope he had the building to the standards of the Ontario Building Code when the units were created. Codes do change in the building construction and material types over the years to improve structure and longevity. But when it comes to FIRE CODES building with tenants in living spaces must be changed & improved to meet the new codes as they change for what is called the safety of the tenant.

Does sound like this could get messy, but hope for you your ducks are in line.

ALL THE BEST