Quick answer#
Changing how a building or tenant space is used may require a building permit, even when very little construction is proposed.
Municipalities review whether the new use changes the occupancy classification or introduces new Building Code requirements.
A simple business change can sometimes require significant upgrades before occupancy is approved.
What is a change of occupancy?#
A change of occupancy occurs when a building or tenant space begins operating under a different occupancy classification than it was originally designed for.
The physical space may appear almost identical, but the risks associated with the new use can be completely different.
Because of this, municipalities often review the project before the new business opens.
Common examples#
Retail store to daycare.
Office to medical clinic.
Warehouse to fitness centre.
Restaurant to retail.
Office to restaurant.
Retail to cannabis store.
Warehouse to brewery.
Commercial unit to assembly use.
Why municipalities review occupancy changes#
Different occupancies create different life-safety risks.
The number of occupants, emergency exiting, plumbing demand, accessibility, ventilation, fire protection and structural loading may all change depending on the proposed business.
Municipal review helps ensure the building remains safe for its intended use.
Occupancy classification#
One of the first questions during permit review is whether the proposed business falls into a different occupancy classification.
This single decision can affect dozens of Building Code requirements throughout the project.
Understanding occupancy classification early often prevents costly redesign.
Typical Building Code topics reviewed#
Occupant load.
Means of egress.
Fire separations.
Barrier-free design.
Accessible washrooms.
Mechanical ventilation.
Fire alarm systems.
Emergency lighting.
Structural capacity.
Plumbing fixture counts.
Examples from real projects#
Converting a retail unit into a daycare may require significant plumbing, accessibility, fire safety and exiting upgrades.
Changing an office into a medical clinic often affects occupant load, accessibility, waiting areas and plumbing fixtures.
Transforming a warehouse into a fitness facility may increase occupant load dramatically and require additional exits, washrooms and ventilation.
Common permit review comments#
Confirm proposed occupancy classification.
Provide code summary.
Provide occupant load calculations.
Show exit travel distances.
Confirm accessible route.
Provide washroom calculations.
Identify fire-rated assemblies.
Coordinate mechanical drawings.
Common mistakes#
Signing a lease before confirming permit feasibility.
Assuming the previous tenant's permit applies to the new business.
Ignoring occupancy classification.
Ordering equipment before permit approval.
Beginning construction before understanding municipal requirements.
Planning before leasing a space#
Before signing a commercial lease, determine exactly how the space will be used.
Review zoning, occupancy classification, parking, Building Code requirements and accessibility before investing in design or construction.
Early due diligence often saves months of redesign and unexpected costs.
How PermitWave helps#
PermitWave helps identify whether a proposed business may trigger a change of occupancy review before construction begins.
The permit preview organizes the project scope, identifies common Building Code issues and highlights information municipalities frequently request.
This allows business owners to make better decisions before signing leases or hiring contractors.