Short answer: a modular garden suite in Toronto or Mississauga goes through nine steps: lot check, design, zoning check, building permit, factory build, site work, delivery and placement, inspections, and occupancy. Three of them are city steps with published review times. Every city step below links to the official page it comes from. Times are city targets or estimates, not promises.
Key takeaways
| Question | Short answer | Source |
|---|---|---|
| Toronto permit review | 10 business days for a complete application (house stream); the zoning certificate (ZAP) is required first | City of Toronto |
| Mississauga permit review | The first review may take 15 business days; each round of changes can add two weeks or more | City of Mississauga |
| Crane or truck on the street | Toronto: street occupation permit, about 12 weeks. Mississauga: road occupancy permit | Toronto · Mississauga |
| Inspections | Done by city inspectors at the stages set by the Ontario Building Code | O. Reg. 163/24 |
The 9 steps at a glance
- Lot check: survey, zoning, setbacks, trees, servicing and access.
- Design and drawings: a layout that fits the lot, and permit drawings.
- Zoning check: Toronto ZAP; in Mississauga, an optional preliminary zoning review or a pre-approved plan.
- Building permit: the city reviews a complete application.
- Factory build: modules built indoors in a factory.
- Site work: foundation and service connections from the house.
- Delivery and placement: crane day, with a street or road permit if needed.
- Inspections: city inspectors at the code stages.
- Occupancy: final inspection, then move-in.
1. Lot check
Before design starts, confirm what the lot allows: the zoning rules, setbacks, the fire access path, servicing from the house, and whether a protected tree is nearby. In Toronto, injuring or removing a protected tree needs a permit (City of Toronto). Also check access: side-path width, overhead wires and a spot for the crane. Start with a free lot check. The rules for each city are compared in the GTA garden suite rules comparison.
2. Design and drawings
The design has to fit the size, height and setback limits for your lot. Toronto's new garden suite guide lists what the permit drawings must show. In Mississauga, a pre-approved garden suite plan can be used where the lot fits.
3. Zoning check
Toronto: a Zoning Applicable Law Certificate (ZAP) is part of a complete building permit application (City of Toronto). Mississauga: an optional preliminary zoning review runs in rounds of about 20 business days (City of Mississauga). Details are in the Toronto permit guide and the Mississauga permit guide.
4. Building permit
Toronto: 10 business days for a complete application in the house stream (City of Toronto). Mississauga: the first review may take 15 business days, and each round of changes can add two weeks or more (City of Mississauga). These are the cities' review targets. The time to get an application complete depends on the lot.
5. Factory build
The modules are built indoors in a factory. Ontario explains how factory-built homes are regulated (Government of Ontario). To check any builder's factory, see the builder checklist and what a modular home is.
6–7. Site work, delivery and placement
Site work covers the foundation and the service connections from the house. If the crane or truck has to use the street or lane, a separate permit is needed. In Toronto, a street occupation permit takes about 12 weeks to process (City of Toronto). In Mississauga, it's a road occupancy permit (City of Mississauga). Apply early, so the permit is ready by crane day.
8. Inspections
City building inspectors inspect the work on site at the stages the Ontario Building Code sets (O. Reg. 163/24). Each city explains how to book them: Toronto · Mississauga.
9. Occupancy
After the final inspection passes, the suite can be occupied, following the city's process for your permit.
What you'll see from us
This is how we plan a suite. It's process, not promises:
- A lot-check checklist: zoning, setbacks, fire access, trees, servicing and crane access, each with its city source.
- A permit timeline for your city: city review targets linked to the official page; anything else is labelled as an estimate.
- The inspection sequence: which code stages apply to your suite, and how they are booked.
- The list of sources: every rule we use, linked to its official page.
Start with a free lot check.
Sources
- City of Toronto: building permit review streams
- City of Toronto: Zoning Applicable Law Certificate
- City of Toronto: new garden suite guide
- City of Toronto: when to apply for a tree permit
- City of Toronto: street occupation permit
- City of Toronto: about building inspections
- City of Mississauga: additional residential units
- City of Mississauga: pre-approved garden suite plans
- City of Mississauga: preliminary zoning review
- City of Mississauga: building permit application process
- City of Mississauga: road occupancy permit
- City of Mississauga: book a building permit inspection
- Ontario Building Code, O. Reg. 163/24
- Government of Ontario: building a modular house