Garden Suite Building Permits in Ontario: What to Submit, What It Costs, Why It Bounces
Every garden suite in Ontario needs a building permit from your municipality, and many towns add a planning review before it or a registration after it. The permit fee is usually the smallest number in the project. The drawings, the site plan and getting the application "complete" are where the time goes.
At a glance
The 10 business days start when the application is complete. Electrical is permitted and inspected separately by the ESA.
You apply to your town’s building department with a site plan, grading plan, floor plans, elevations, sections, energy and heat loss documents and designer forms. Fees run from about $1,200 in Toronto for a 60 m² suite to $2,700-plus in Brampton once planning review and registration are added. Once complete, a house-type permit should be decided in 10 business days.
Who Issues a Garden Suite Permit (and Who Else Gets a Say)
Your local municipality’s building department issues the building permit. In a two-tier county, that is the town or township, not the county. The chief building official’s staff check the drawings against the Ontario Building Code and confirm the zoning by-law is met.
Then there is the supporting cast. Depending on your lot, any of these may need to sign off before or alongside the building permit:
- Planning or zoning review. Brampton sends garden suites through its Planning Division first, for urban design, zoning and engineering. Other towns run a zoning check inside the permit review.
- Committee of Adjustment. If you miss a zoning number, you need a minor variance. See Minor Variance for a Garden Suite.
- Conservation authority. Near a creek, slope, shoreline or wetland, you need their permit too. Brampton names CVC and TRCA; Kitchener names the GRCA.
- Tree protection. Toronto wants a Tree Declaration Form when private or City trees could be damaged.
- Septic approval. On a rural lot, a separate sewage system permit from the municipality, health unit or conservation authority, depending on where you are.
- ESA. Electrical permits and inspections come from the Electrical Safety Authority, not the town.
Documents You Need for a Complete Application
This is Toronto’s list for a new garden suite, which is a good model for most of Ontario. Your town may add a survey, a servicing plan or its own forms.
Site plan
Property lines, lot area, easements, existing and proposed buildings with setbacks, a zoning summary (lot area, GFA, coverage, grades), parking, driveways, landscaping, and the fire access path.
Lot grading plan
Existing and proposed grades. Toronto’s rule: no new ponding on your lot or the neighbour’s. Some towns want it from an engineer or surveyor.
Floor plans
Every level, fully dimensioned, with plumbing fixtures and the smoke and carbon monoxide alarm locations.
Roof plan
Layout, slopes, ventilation, skylights. Truss and engineered joist drawings if you use them.
Elevations
Finishes, windows and doors, height, and the exposed building face and unprotected openings for spatial separation.
Sections and details
Footings, foundation, wall and roof assemblies, stairs, guards and handrails, materials.
Energy and HVAC
Energy Efficiency Design Summary (Part 9), plus heat loss and duct design. Toronto takes the mechanical permit separately if HVAC is included.
Designer forms
Schedule 1 Designer Information for each designer who is not an architect or engineer. Drawings signed, dated, to scale, as PDFs.
Town extras
Application to Construct, plumbing data sheet, road damage form, tree declaration, legal survey (Brampton requires one), registration application.
Last checked October 2026 · Source: City of Toronto, New Garden Suite permit guide
Using a municipal pre-approved plan? It covers the building. It does not cover your site plan, grading, servicing route or, in many towns, the heat loss. See Pre-Approved Garden Suite Plans for what each town’s plans include and leave out.
What Garden Suite Permits Cost in Five Ontario Towns
Published fees only. Drawings, survey and engineering are extra and usually cost more than the permit.
| Municipality | Fees as published | Notes |
|---|---|---|
| Toronto | $18.56 per m² (Group C residential) plus $56.33 per new unit, effective Jan 1, 2026. A 60 m² suite: about $1,114 + $56.33 = roughly $1,170 | The $214.79 Zoning Use Review checks uses only, not built form, so it will not answer setback or height questions. DCs exempt on 2nd to 4th units |
| Brampton | Planning review $530 plus $5,000 security; registration $200; building permit $2,004.10; education DCs at issuance | Planning approval comes first; legal survey required; inspection recall fee after two failed inspections; $750 to $1,200 penalty for not registering an ARU |
| Whitby | ADU registration $268 ($534 if discovered through a complaint; $107 to transfer) | 2026 HAF program reimburses the ADU permit fee, registration inspection fee and, for detached ADUs, education DCs. Complete application by Dec 31, 2026 |
| Barrie | ARU building permit fees, including zoning and water fees, cut 50% for applications in 2026; full rebate if occupancy within 12 months of permit | Pre-screening, DCs, revisions and re-inspections not covered. Permit must be issued by Dec 31, 2026 |
| Mississauga | Building permit fee refunded by cheque once construction and inspections are complete (2nd and 3rd units) | City DCs and parkland exempt; school board DC may be payable; free pre-approved garden suite plans |
Last checked October 2026 · Sources: Toronto, Toronto zoning review, Brampton, Whitby, Barrie, Mississauga
For more incentive programs that pay back permit fees, see the Grants and Loans Directory. For fees in other towns, see Garden Suite Rules by City. For the full budget, see Garden Suite Cost and development charges.
The Permit Process, in the Order It Happens
Confirm the lot works
Zoning numbers, servicing route, fire access path, trees, conservation authority, septic capacity if rural. Use the free Rules Checker, then the $399 + HST Lot Report if it looks like a yes.
Get a current survey
Setbacks are measured from property lines, not from the fence your neighbour built in 1987. Brampton requires a legal survey. Most designers will want one anyway.
Design and draw
Floor plans, site plan, grading, structure, energy compliance, heat loss and duct design. Custom, kit or a municipal pre-approved plan. See floor plans and kits.
Planning review or variance, if your town needs it
Brampton’s Planning approval, a conservation authority permit, a tree permit, or a minor variance. Each one has its own clock.
Submit the building permit
Online in most towns. Pay the fee. The province’s guide says you will hear back within 10 business days on a complete application. Expect a list of comments on the first round if anything is missing.
Answer comments and get the permit
Revise, resubmit, pay any development charges that apply (often only school board charges), post the permit placard on site.
Build and call for inspections
You or your builder must notify the building department at each stage. Do not cover work that has not been inspected.
Final, occupancy and registration
Final building inspection, ESA final, and in towns like Whitby and Brampton, the ARU or ADU registration. Many grant programs only pay after this step.
How Long a Garden Suite Permit Really Takes
The provincial target is 10 business days after a complete application for a house-type permit, per the ontario.ca second unit guide. That is the review clock. It is not the whole calendar.
Realistic, on a serviced urban lot with no variance: one to three months for drawings, then two to six weeks of review, comments and resubmission. Add a planning review, conservation authority permit or tree permit and you are into months. A minor variance adds its own hearing schedule. On rural lots, septic design and approval run alongside and can be the long pole in the tent.
The single biggest time-saver is a first submission that is actually complete. We will say it again, because it is the whole trick: the clock does not start until the application is complete. More on the full project schedule at Garden Suite Timeline.
What Inspectors Check at Each Visit
The exact list is on your permit. These are the usual stages for a house-type building like a garden suite, and the things we see inspectors stop on.
| Stage | What they look at | Where people get caught |
|---|---|---|
| Excavation / footings | Footing size and depth, bearing soil, location against the site plan | Footing poured before inspection; suite shifted half a metre and now a setback is short |
| Foundation before backfill | Damp-proofing, drainage, wall thickness, anchor bolts, insulation if exterior | Backfilled early; no drainage layer; slab insulation not as drawn |
| Underground plumbing and building sewer | Pipe size, slope, bedding, test, connection to the existing lateral or septic | Not enough fall to the sewer; old clay lateral that needs replacing |
| Framing | Structure as drawn, lintels, bracing, trusses or engineered joists with their drawings, stairs and guards | Truss drawings missing; window moved without updating spatial separation |
| Rough-in plumbing and HVAC | Venting, traps, ductwork matching the heat loss and duct design, combustion air, exhaust fans | Equipment swapped for a different size than the design |
| Insulation and air/vapour barrier | R-values and assemblies matching the energy compliance path, sealed air barrier | Drywall hung before the inspector came |
| Fire separations (if any) | Rated walls near property lines, limited unprotected openings, rated assemblies as drawn | Suite close to the lot line with a big window on that wall |
| Final / occupancy | Smoke and CO alarms, guards, handrails, exits, grading, address, everything done | No CO alarm; grading sends water at the neighbour; ESA final missing |
Last checked October 2026 · Source: ontario.ca, Add a second unit; your permit lists the required inspections for your project
Rural lots add a septic inspection before the system is covered. Electrical is inspected by the ESA. Toronto requires smoke and CO alarm locations right on the floor plans, which tells you how much inspectors care about them.
Nine Reasons Garden Suite Applications Come Back
- No site plan, or a site plan drawn on an old survey. Setbacks measured from the wrong line are the number one zoning comment.
- Fire access path not shown. Toronto wants a path generally 1.0 m wide and 2.1 m high, no more than 45 m from the street. Mississauga uses 1.2 m wide. If it is not on the drawing, it does not exist.
- Height measured the wrong way. Every by-law defines height from a specific grade to a specific point on the roof. Read the definition, not just the number.
- Missing heat loss and duct design, or one done for a different house.
- Missing energy efficiency summary, or one that does not match the wall and window specs on the drawings.
- Spatial separation ignored. A suite tight to the lot line can only have so much glass on that wall.
- No grading plan, or one that drains onto the neighbour’s yard.
- Unqualified designer. No Schedule 1, no BCIN, or a BCIN in the wrong category.
- Other approvals not cleared. Conservation authority, tree permit, planning approval, or a variance that is not yet final and binding. Whitby, for one, wants the variance final before the application counts.
Want the first submission to be the only submission?
Send your plan, kit model or sketch with your survey. We reply with a fixed quote for the site plan, heat loss and forms, plus septic design through our partner on rural lots. From $1,499.99 + HST.
BCIN, Heat Loss and Septic: Who Is Allowed to Draw What
BCIN designers. In Ontario, permit drawings come from a licensed architect, a professional engineer, or a designer who is qualified and registered with the province and holds a BCIN (Building Code Identification Number) in the right category. The House category covers the architectural set for a garden suite. The province’s guide recommends exactly that and links a public search tool to check a designer’s registration. Use it. It takes a minute.
Doing your own drawings. The Building Code has a limited exemption for owners designing for themselves. Ask your building department whether it applies to your garden suite before you start. Even when it does, the drawings have to be just as complete, and in our experience owner-drawn sets are the ones that come back with the longest comment lists.
Heat loss and HVAC. The heating and duct design is its own discipline and its own BCIN category. Your town will want a room-by-room heat loss and a duct or heat pump design that matches the building on the drawings. That is what OntarioHeatLoss.ca does, stamped and ready for the permit.
Septic on rural lots. A garden suite adds a kitchen and a bathroom, so the septic design flow goes up. That needs a separate sewage system permit and a designer qualified for on-site sewage systems. Where it is issued depends on where you live: Cavan Monaghan, for example, sends septic permits to Peterborough Public Health. We do not design septic systems. That work goes through SepticReplacement.ca. Start with Garden Suites on Well and Septic and Temporary Garden Suites.
Five Things to Do Before You Apply
- Measure the fire access path with a tape and a friend. Width, height, and distance from the street to the suite door.
- Find your sewer lateral depth and material before you design the floor height.
- Call your building department and ask: "Do you require a planning review, a registration, or a grading plan stamped by an engineer for a detached ARU?" Write down the answer and the name of the department.
- Check whether a conservation authority regulates your lot. Most have an online map.
- Get every designer’s BCIN and check it on the provincial registry before you pay a deposit.
New to all this? Start with the pillar guide, Garden Suites in Ontario, then Garden Suite Rules and How Big Can a Garden Suite Be?.
Get the drawings right once.
Find out what your lot allows in 48 hours with the $399 + HST Lot Report, or send us your plans and get a fixed price for a complete permit package.
Garden Suite Permit Questions
Do I need a building permit for a garden suite in Ontario?
Yes. A garden suite is a dwelling unit under the Ontario Building Code, so it always needs a building permit from your municipality, plus an ESA electrical permit. Some towns also require a planning review before the permit (Brampton) or a registration after it (Whitby, Brampton). On rural lots, the septic system needs its own permit.
How much is a garden suite building permit in Ontario?
It depends on the town. Toronto charges $18.56 per m² plus $56.33 per unit in 2026, so about $1,170 for a 60 m² suite. Brampton lists a $2,004.10 building permit plus a $530 planning review, $5,000 security and $200 registration. Barrie cuts ARU permit fees 50% in 2026, and Mississauga refunds the permit fee after inspections.
How long does it take to get a garden suite permit?
The province expects a decision within 10 business days of a complete application for a house-type permit. In practice, add a round or two of comments, and add months for a planning review, conservation authority permit, tree permit or minor variance. Drawings usually take one to three months before you can apply.
What drawings do I need for a garden suite permit?
A site plan, lot grading plan, floor plans with alarm locations and plumbing fixtures, roof plan, elevations with spatial separation details, sections and construction details, an energy efficiency design summary, a heat loss and duct design, and Schedule 1 designer information. Many towns also want a legal survey.
Can I draw my own garden suite plans?
The Building Code has a limited exemption for owners designing for themselves, so ask your building department whether it covers your project. Otherwise, drawings must come from an architect, engineer or a BCIN-registered designer in the right category. Either way, the set must be complete, and incomplete sets are the main cause of delays.
Do I need a heat loss calculation for a garden suite?
In practice, yes. Towns want a room-by-room heat loss and a duct or heat pump design that matches the building on the drawings, prepared by a qualified designer. Toronto takes HVAC under a separate mechanical permit. OntarioHeatLoss.ca prepares stamped heat loss and HVAC designs for permits.
What inspections does a garden suite need?
Typically footings, foundation before backfill, underground plumbing and sewer, framing, rough-in plumbing and HVAC, insulation and air barrier, any fire separations, and a final for occupancy. ESA inspects electrical separately, and rural lots add a septic inspection. Your permit lists the stages that apply.
Do I need a septic permit for a garden suite on a rural lot?
Usually yes. The suite adds a kitchen and a bathroom, which raises the septic design flow, and the existing system often has to be enlarged or replaced under a separate sewage system permit. The permit comes from the municipality, health unit or conservation authority depending on your area. Septic design is done through SepticReplacement.ca.