Thinking about a garden suite on your Toronto property? This all-in-one guide explains everything about the garden suite permit in Toronto — including the rules, exact permit steps, realistic timelines, and true-to-market costs. You’ll also learn how to speed up approvals with the City’s pre-approved plan sets and a smart zoning pre-check.
What is a garden suite?
A garden suite is a self-contained dwelling in a detached building located in the rear yard of a low-rise residential lot. It stays on the same title as the main house (no severance), has its own kitchen, bathroom, and sleeping area, and can be one or two storeys depending on your site.
What is a garden suite?
| Topic | Snapshot |
|---|---|
| Where allowed | Most low-rise residential lots city-wide, subject to zoning and site conditions |
| Max footprint | Smaller of 60 m² (≈646 sq ft) or 40% of the rear yard |
| Ancillary coverage | All backyard buildings together ≤ 20% of lot area |
| Typical height | About 4.0 m near the house; two-storey often feasible with greater separation and angular planes |
| Setbacks | Rear ~1.5 m typical; side 0.6 m or 10% of frontage (may increase with windows/doors) |
| Soft landscaping | Many wider lots must keep ≥50% of the rear yard as soft landscape |
| Parking | No car stall required for the suite; 2 bicycle spaces required |
| Basement | Permitted if designed, drained, and protected correctly |
| Development charges (DCs) | Exempt for qualifying additional residential units; City has extended DC exemptions up to six total units on a lot—confirm your scenario |
| Review target | ~10 business days for complete House Stream submissions |
The rules that set your “buildable box”
Start with a current legal survey. Measure rear-yard depth, note any existing sheds/garages, and mark lot lines. Your maximum footprint is the smaller of 60 m² or 40% of the rear yard. If you already have a garage or shed, the combined coverage of all backyard buildings cannot exceed 20% of the lot area.
Height depends on distance from the main house. Closer buildings are held to a lower profile. With more separation (often around 7.5 m), two storeys may be possible, subject to angular plane and privacy rules.
Setbacks protect neighbours and services. Plan façades early: windows and doors near side yards can trigger larger setbacks for fire and privacy, so shifting an opening a little can save months later.
Soft landscaping isn’t optional. Many lots over 6 m frontage must keep at least half the rear yard as permeable landscaping. Sketch walks and patios after you run the landscape math.
Trees, fire access, and servicing
Trees can define your footprint. If a protected trunk or root zone overlaps the build area, you’ll likely need an arborist report and a Tree Protection Zone (TPZ). Designing around significant trees is usually faster and cheaper than removal permits and replacement costs.
Fire access is mandatory. You need a clear path from the street to the suite that meets width, height, and travel-distance criteria. Confirm gate widths and fence placements before you finalize drawings.
Servicing is straightforward on most lots. Typical solutions connect water and sanitary to the main house; electrical can come from the existing panel or a new dedicated service. Show logical routes and notes for trenching, protection, and backflow where applicable.
The permit process, step-by-step
1) Feasibility & site due diligence (1–3 weeks)
Order a recent survey. Walk the site with your designer. Measure side-yard widths, confirm rear-yard depth and grades, map trees/utilities, and take photos of the intended fire-access path. If you’re near a ravine or regulated area, flag it early.
2) Zoning pre-check with a ZALC (optional, 1–3 weeks)
A Zoning Applicable Law Certificate (ZALC) documents how your proposal fits zoning and applicable laws. It’s optional but smart: it de-risks the building-permit stage and helps ensure your application is treated as complete.
3) Choose your design path: custom vs pre-approved (in parallel)
You can commission a custom design or adapt one of the City’s pre-approved plan sets for garden/laneway suites. Pre-approved plans are Building-Code-ready frameworks that can cut design time and reduce comments. You still need a site plan, tree plan, servicing, and grading notes tailored to your lot.
Custom design shines on tricky lots, narrow side yards, or sites with major trees. Pre-approved plans shine when speed, predictability, and budget are top priorities.
4) Assemble a complete permit package (2–6 weeks)
Aim for completeness on day one so you hit the House Stream timeline.
Include:
Survey and dimensioned site plan with setbacks, coverage, and soft-landscape calculations
Floor plans, elevations, building sections, assemblies, and key details
Fire-access diagram with clear path dimensions and obstructions noted
Energy compliance (SB-12) and mechanical/ventilation notes
Servicing diagram for water, sanitary, and electrical
Arborist report and tree-protection plan if required
ZALC letter (if obtained) to streamline zoning questions
5) City review in the House Stream (~10 business days for complete apps)
Complete submissions target an initial review in about 10 business days. If you receive a clarification notice, respond quickly and completely—piecemeal answers delay your file.
If you need relief on items like setbacks or main-wall height, you’ll apply to the Committee of Adjustment (CofA). Budget the hearing date, decision timeline, and any conditions; this can add months. If schedule is tight, design by-right and skip variances.
6) Permit issuance & inspections
After issuance, inspections occur at key milestones: footing/foundation, framing, plumbing, insulation/air barrier, and final. Keep TPZs intact until completion.
How long does it really take?
| Phase | Typical duration |
|---|---|
| Feasibility & survey | 1–3 weeks |
| ZALC pre-check (optional) | 1–3 weeks |
| Design & documentation | 2–6 weeks (faster with pre-approved plans) |
| City review (complete House Stream) | ~10 business days |
| Committee of Adjustment (if needed) | +2–4 months |
| Construction | 4–6 months (1-storey), 6–10 months (2-storey) |
What does a garden suite cost in 2025?
Every site is unique, but these ranges are solid for early budgeting and contractor comparisons:
| Cost item | Typical range (2025) |
|---|---|
| Survey & site recon | $2,500–$4,000 |
| Design/architecture (custom or adapting pre-approved) | $10,000–$25,000 |
| Building permit & City fees | $1,200–$2,500+ (area/fixtures dependent) |
| ZALC fee (if used) | Often flat; treated as a prerequisite for a “complete” submission |
| Tree/ravine permits & replacement | Variable (site specific) |
| Utility connections & upgrades | $10,000–$30,000+ |
| Turnkey construction | ~$250–$450+ per sq ft (spec- and height-dependent) |
| Landscaping, paths, fencing | $5,000–$20,000+ |
| Contingency | 10–15% of total project |
Sample permit-fee logic
For a ~60 m² suite, the core calculation (service index × area) often lands near $1,000–$1,100 before per-unit and plumbing-fixture additions. Many projects finish around $1,200–$2,500+ depending on counted area, fixtures, and any extra review time. Your actual fee follows the current City fee schedule and your final drawings.
Development Charges (DCs) in 2025
Garden suites that qualify as additional residential units are exempt from Development Charges. As of mid-2025, City Council also extended DC exemptions up to six total units on a lot, which can cover combinations like a multiplex plus a laneway/garden suite. Always confirm how your exact configuration is treated at the time of application.
Pre-approved plans: when they make sense
City pre-approved plan sets are ideal if you want predictable design, fewer comments, and lower design time. They’re built to code and focus on efficient footprints, clear wall assemblies, and sensible structure. You still customize siting, grades, windows/doors, and servicing to your lot.
They’re strongest on rectangular lots with clean side access and manageable trees. On irregular lots, a custom design may squeeze out more area, privacy, and light—while still avoiding variances.
Common pitfalls (and how to avoid them)
Ignoring tree constraints. Protected trees can force late redesigns. Start with an arborist screen and shape the footprint around TPZs.
Forgetting fire access. Measure side yards and gate openings now. Draw the path and keep it clear on the site plan.
Submitting “almost complete.” Missing SB-12, vague servicing, or no tree plan can push you out of the House Stream window. Use a checklist and upload once—thoroughly.
Chasing preventable variances. CofA can add months. If the goal is speed, design inside the by-right envelope and keep massing simple.
Under-planning utilities. Confirm tie-in locations, trench routes, and electrical capacity early—especially if the main house needs a service upgrade.
Basements: yes or no?
Basements are allowed and useful for storage, mechanicals, and future flexibility. Balance excavation, waterproofing, and egress costs against program needs. A conditioned crawlspace can deliver utility space with less risk on tight budgets.
Rental potential & long-term value
A well-planned one-bedroom garden suite can generate strong rental income, especially near transit and employment hubs. Prioritize privacy, sound separation, natural light, and durable finishes. Even if you don’t rent right away, a legal, permitted suite with final inspections and as-built drawings is a long-term value add for resale.
Pre-submission checklist
- Recent legal survey and dimensioned site plan
- Soft-landscape calculations and ancillary-coverage math
- Fire-access path confirmed on plan and on site
- Arborist review and tree-protection strategy
- Architectural set with elevations, sections, assemblies, and details
- Energy (SB-12), mechanical notes, and ventilation strategy
- Servicing layout for water, sanitary, and electrical
- ZALC letter if you chose the pre-check path
- Decision between custom and pre-approved plans
Frequently asked questions
No. The suite itself doesn’t require a car stall. Provide two bicycle spaces and maintain any parking obligations for the main house.
The footprint is limited to the smaller of 60 m² or 40% of the rear yard. The sum of all accessory buildings cannot exceed 20% of lot area.
Often yes, with greater separation from the main house and compliance with angular plane and height limits. Deeper lots have the best odds.
Qualifying additional residential units are currently exempt. In 2025, Council also extended DC exemptions to up to six units on a lot; confirm your exact configuration.
Complete House Stream submissions target around 10 business days for initial review. Variances via the Committee of Adjustment add months.
If you injure or remove a protected tree—or you’re in a ravine/regulated area—you’ll need permits and robust protection measures.
No. Garden suites remain on the same lot and title as the main house.
It depends on storage/mechanical needs, soil conditions, and budget. A shallow basement or conditioned crawlspace can be a smart middle ground.
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