The Short Answer
For a straightforward residential permit in most Ontario municipalities, expect 4 to 8 weeks from a complete submission to an issued permit. A commercial or Part 3 project typically runs 8 to 16 weeks. A complex industrial or multi-residential file can run 5 to 8 months.
But the honest answer to "how long does a permit take" is: it depends almost entirely on the quality of what you submitted. The Ontario Building Code Act sets a statutory review clock — municipalities must review a residential application within a defined period — and that clock restarts every time you resubmit. A complete set runs on the municipality's schedule. An incomplete set runs on yours, at three to five weeks per round.
Real 2026 Timelines by Project Type
These are working ranges from projects we've drawn across the GTA and Ontario. Municipal processing speeds vary significantly — some are genuinely fast, some are chronically backed up — but the spread within a project type is usually about as wide as the spread between municipalities.
| Project Type | Review Time | Key Variable |
|---|---|---|
| Basement finish / interior alteration | 2–6 weeks | Whether structural work is involved |
| Deck, porch, or detached garage | 2–5 weeks | Zoning setback compliance |
| Home addition (Part 9) | 4–10 weeks | Zoning, energy compliance, structural |
| Custom home (Part 9) | 6–12 weeks | Site servicing, grading, conservation |
| Secondary suite / basement apartment | 6–14 weeks | Fire separation and egress, zoning permits |
| Commercial fit-out / restaurant | 8–16 weeks | Part 3 review, health, zoning, parking |
| Industrial / warehouse | 10–20 weeks | Site plan control, MZO/MZ, fire routes |
| Multi-residential (Part 3) | 4–8 months | Full consultant coordination, site plan |
Ranges assume a complete first submission. Add 3–5 weeks per deficiency cycle.
The Three Things That Actually Decide Your Timeline
Almost every delayed permit traces back to one of three causes. None of them are the municipality's fault, and all three are controllable before you submit.
Missing or incomplete drawings
No elevations, no wall sections, no fenestration schedule, no dimensions that reconcile. The reviewer can't approve what isn't drawn, so the file sits until it's complete. This is the single most common cause of a first-round deficiency.
No P.Eng.-sealed structural package
Any project touching load-bearing walls, floor openings, foundations, or lateral systems requires sealed structural drawings. Municipalities will not issue the permit without them — and they will hold the entire file, not just the structural portion, until they arrive.
Zoning and compliance gaps
Setbacks, height, lot coverage, parking, or a missing SB-12/SB-10 energy form. These are checked at intake, so they can stop your file before a plans examiner ever opens it.
“We have never once seen a permit approved faster because the applicant asked nicely. We have seen dozens approved faster because the drawing set was complete on day one.”
September Is the Right Time to Start
There's a seasonal pattern to Ontario permitting that most homeowners don't know about. Municipal building departments process applications continuously, but the volume of submissions is not constant. Late winter and early spring — when everyone wants to break ground for summer — is the busiest intake period of the year.
Applications submitted in September and October tend to move through review faster, and they land you with an issued permit and a completed design before the ground freezes. That means you can either start foundation and structural work in the late fall, or be first in line to break ground the moment conditions allow in spring.
Starting drawings in September also means there's time to correct a deficiency without the correction costing you your entire build season. If a file submitted in May comes back deficient, you've lost the summer. If a file submitted in September comes back deficient, you've lost a few weeks of a season you weren't going to build in anyway.
What You Can Do to Shorten Yours
A few concrete steps, in order of how much time they save:
- Commission the structural package up front. Not "if the municipality asks." If your project touches anything structural, the sealed drawings need to be in the first submission. Waiting for the deficiency adds a full review cycle.
- Confirm your zoning before you draw. A fifteen-minute zoning check against setbacks, height, and lot coverage prevents a file that's unfixable without redesign.
- Include the energy compliance form. Ontario requires SB-12 (residential) or SB-10 (commercial) with project-specific inputs. A generic or partially blank form reads as incomplete.
- Pre-consult for anything non-standard. Commercial, industrial, and any project with a variance or site plan component benefit enormously from a municipal pre-consultation meeting. It surfaces the real requirements before you spend on drawings.
- Have one team own the whole package. Architectural, structural, and energy coordinated by one firm means the drawings reconcile. Files rejected for internal inconsistency are the most avoidable delay of all.
Building Permit Timelines Across the GTA
Municipal processing speeds vary across the region. Find your city for local timelines, requirements, and the specifics of how that building department reviews files:
May Engineering Inc: Permits That Clear Review
May Engineering Inc prepares complete permit drawing packages — architectural, structural, and energy compliance in one coordinated submission, sealed by a licensed Professional Engineer. We submit across Brampton, Mississauga, Toronto, Vaughan, Markham, and every municipality in between, and we know what each one asks for.
Our files are built to clear review the first time, because the fastest permit is the one that never comes back. Send us your project details and we'll tell you what your submission needs — and how fast it can realistically move.
Ready to start your permit?
Free initial consultation. Firm pricing on a complete drawing package. Ontario-wide service.