Most tenants don’t find out they needed a change of use permit until they’re already three weeks into construction.
By that point, the contractor has stopped work, the city is asking for drawings that don’t exist yet, and the opening date written into the lease is no longer realistic. It’s an expensive problem. It’s also a predictable one.
Quadrant Architects works with business owners and tenants taking over commercial units in Toronto and the GTA. We identify permit obligations, code triggers, and zoning issues before design begins – so the path from lease signing to opening day stays on track.
Licensed by the Ontario Association of Architects (OAA) with full professional liability insurance.
When a new tenant moves into a commercial unit, one question shapes everything else: is your business the same type as the previous tenant, or is it different?
If you’re a café taking over a space that was previously a café, your permit path is relatively straightforward – interior alteration, standard review. If you’re opening a medical clinic in a space that was previously a travel agency, the use has changed. That change triggers a permit review even if you’re not planning to touch a single wall. Toronto Building requires a permit when a building’s use changes, regardless of whether construction is proposed.
That distinction – same use or different – determines whether you’re looking at a routine fit-out or a change of use application with additional code requirements. We make that call at the start, before you’ve committed to a design.
Taking over a vacant retail or office unit and fitting it out for your operations. This covers new walls, service counters, treatment rooms, washrooms, lighting, and ceiling layouts – everything needed to make the space work for your business.
We’ve done this for a restaurant at Daymi in Toronto, a dog grooming studio at 16 Blue Jays Way in a downtown condominium building, and a cosmetic clinic for BB Cosmetic Clinic in Thornhill. Each project started from an existing shell and required drawings coordinated across architecture, mechanical, electrical, and plumbing
Permit drawings include: floor plans, reflected ceiling plans, partition layouts, washroom design, door and hardware schedules, life safety review, and coordination with engineering consultants where required.
What this means for you: A properly coordinated fit-out package clears permit review faster, gives your contractor a complete set to build from, and reduces the back-and-forth that pushes opening dates back.
When the proposed business type differs from the previous occupancy, a change of use application is required. This can happen even when the space itself looks right for the new use.
At our Lakeshore Pharmacy and Clinic project, the combined pharmacy and clinic use required review of occupancy classifications, barrier-free access, and washroom fixture counts – none of which were issues for the previous tenant but became relevant as soon as the new use was confirmed.
The common change of use situations we handle: retail converting to food service, office converting to personal services or medical, warehouse space converting to a retail or assembly use, and mixed-use units where the tenant mix changes significantly.
What this means for you: If the city identifies a use change during an inspection and no permit was pulled, work stops immediately. We prevent that by reviewing the existing and proposed use at the start and confirming the permit path before construction begins.
Reconfiguring an existing commercial unit – adding or removing walls, relocating a service counter, redesigning washrooms, upgrading an accessible entrance – without increasing floor area.
Even changes that feel minor often require permit review. Adding a partition in a medical office changes the travel distance to exits. Relocating washrooms triggers plumbing fixture counts. Widening a doorway for accessibility compliance is a material alteration under the Ontario Building Code.
What this means for you: Understanding what requires a permit before construction starts protects you from stop-work orders, failed inspections, and the cost of redoing work that wasn’t approved.
When a new business moves into an existing space, the space has to comply for the new use – not just for the previous one. That can mean accessibility upgrades, additional washroom fixtures, upgraded fire separations, or mechanical ventilation changes, depending on what the new occupancy type requires under the OBC.
A space that passed inspection for a previous retail tenant may not automatically comply for a new food service tenant. The ventilation requirements alone – exhaust hoods, makeup air, fresh air rates – are occupancy-specific.
What this means for you: Code compliance review happens at the start of design, not at permit submission. Finding a compliance gap mid-drawing set costs time. Finding it during city review costs more.
Step 1 – Existing unit review – We review what’s there: the unit, the previous use, any base building drawings the landlord can provide, and the visible site conditions. We determine the permit path – interior alteration, tenant improvement, or change of use – before a single line is drawn.
Step 2 – Feasibility and code review – Zoning compliance, permitted use, exiting requirements, accessibility obligations, washroom fixture counts, and major OBC triggers – all reviewed before design is finalized. This is where we confirm that the proposed business can operate in the unit without cost surprises.
Step 3 – Design and space planning – Layout options developed around the tenant’s operations, customer flow, staffing, equipment, and permit constraints. A space that works for the business and works for the permit examiner – not one that trades off one for the other.
Step 4 – Permit drawings and consultant coordination – Architectural package prepared and coordinated with mechanical, electrical, and plumbing consultants where required. For non-residential interior alterations in Toronto, the submission requires scaled, dimensioned, signed, and dated drawings showing existing and proposed layouts, along with permit application forms and designer information forms in PDF format.
Step 5 – Permit submission and city review – We submit, track the review, respond to examiner comments, and revise as needed. For straightforward interior alterations with no change of use, Toronto’s standard review runs 4–10 weeks depending on submission completeness and project complexity. Change of use applications take longer. Complete, well-coordinated submissions shorten review time.
Step 6 – Construction support – During construction, we respond to site questions, clarify drawings, and support the project through inspections so the tenant reaches occupancy without a last-minute compliance issue.
A building permit is required in Toronto for most material alterations - adding or removing walls, modifying plumbing or heating systems, or changing the building's use.
A change of use permit is required even when no construction is planned.
The new occupancy type sets the code requirements - not the previous tenant's use.
A single occupancy change can trigger OBC Section 3.7 requirements for washroom counts, accessible routes, and mechanical ventilation.
Some small interior alterations qualify for Toronto's Express permit stream - up to 600 m², no change of use, no change in patron area.
Outside Toronto, permit requirements vary. Markham, Vaughan, and Mississauga each have distinct pre-consultation requirements. We work across all three regularly.
A single occupancy change can trigger OBC Section 3.7 requirements for washroom counts, accessible routes, and mechanical ventilation.
Some small interior alterations qualify for Toronto's Express permit stream - up to 600 m², no change of use, no change in patron area.
We provide commercial architecture services across Toronto and the GTA, including:
Toronto, North York, Etobicoke, Scarborough, Mississauga, Brampton, Vaughan, Markham, Richmond Hill, Pickering, Ajax, Whitby, Oakville, Burlington, Ottawa.
Q: Do I need a permit if I am only renovating the inside of an existing commercial unit?
A: In most cases, yes. Toronto requires building permits for material alterations – adding or removing walls, changing room uses, modifying plumbing or heating systems. Even changes that feel minor can trigger permit review if they affect life safety systems, accessibility, or the building’s structural or mechanical elements. The safest approach is to confirm the permit requirement before construction starts, not after.
Q: I’m taking over a unit where another business already operated. Do I still need a permit?
A: It depends on whether the use is changing. If your business is the same type as the previous tenant and the scope of work is limited, a standard interior alteration permit may apply. But if your business changes the occupancy type – even if the space looks right for you and you’re not planning major construction – Toronto requires a change of use permit. We confirm which situation applies at the start of the project.
Q: What triggers a change of use permit if no construction is planned?
A: Toronto Building requires a permit when a building’s use changes, regardless of whether physical construction is involved. A retail unit converting to a medical office, for example, changes the occupancy classification. That triggers a review of washroom fixture counts, accessible route design, and mechanical ventilation requirements – even if the walls stay exactly where they are.
Q: How long does a tenant improvement permit take in Toronto?
A: For straightforward interior alterations with no change of use, Toronto’s standard review typically runs 4–10 weeks, depending on submission completeness, project complexity, and current review volumes. Applications involving change of use, Committee of Adjustment hearings, or multi-discipline consultant coordination take longer. A complete, well-documented first submission is the most reliable way to reduce that timeline.
Q: Can a small renovation qualify for a faster permit process?
A: Sometimes. Toronto’s Express permit program covers certain small commercial interior alterations, but only where there is no change in use, no change in patron area, and other eligibility conditions are met. Eligible types include business, office, retail, and some small restaurant alterations up to 600 m². We confirm eligibility early – it’s worth checking before assuming a project qualifies.
Q: Do I need an architect for a change of use permit?
A: For most commercial change of use applications above certain size or complexity thresholds, the drawings must be prepared by a qualified designer or OAA-licensed architect. Working with an OAA-licensed architect also means the work carries mandatory professional liability insurance, which matters to landlords, lenders, and the city during the review process.
Q: Who is responsible for the permit – the landlord or the tenant?
A: It depends on the lease and the scope. Most commercial leases assign the tenant fit-out permit to the tenant, with base building items remaining the landlord’s responsibility. The line isn’t always obvious. We review the lease conditions and the existing building conditions at the start of every project so permit responsibility is clear before drawings are issued to the contractor.
Q: What documents are needed for a commercial permit submission in Toronto?
A: Typically: a permit application form, designer information form, and architectural drawings showing the existing and proposed layout – scaled, dimensioned, signed, and dated. Projects with engineering scope require coordinated consultant drawings. Toronto’s non-residential interior alteration guide covers the specific requirements for each project type. We prepare the full package and submit on your behalf.
Every member of our team has advanced education in architecture and design
M.Arch Architect, OAA
Principal
M.Arch.BCIN
Principal
M.Arch.BCIN
Principal
