A garden suite is a separate small home in your backyard, also called a coach house, backyard suite or tiny home. Mississauga allows one per lot, and since June 2024 the City has offered two free pre-approved designs: a 40 m² (430 sq ft) studio and a 55 m² (600 sq ft) one-bedroom. Using one means you skip hiring an architect for the building itself and your permit is reviewed faster.
The plans solve the design. They do not solve the site. You still need a site plan, a grading plan, zoning compliance, services and a fire access path, and you still need to pay to build it. This guide covers all of it, with the zoning numbers for your lot and real 2026 costs.
Will a garden suite fit on your lot?
Enter your lot size and layout. The checker applies Mississauga’s garden suite zoning limits, tells you which pre-approved plan fits, and estimates the permit fee and build cost.
Floor area limits from Zoning By-law 0225-2007 as amended by By-law 0174-2023. Build costs use $400 to $650 per sq ft from GTA builder estimates and are a guide only.
The two pre-approved plans
| Studio | One-bedroom | |
|---|---|---|
| Floor area | 40 m² (430 sq ft) | 55 m² (600 sq ft) |
| Approximate footprint | 8.0 m by 5.0 m | 10.0 m by 5.5 m |
| Layout | Open living, kitchen and sleeping area | Separate bedroom, living area and kitchen |
| Bathroom | One 3-piece | One 3-piece |
| Storeys | One, pitched roof | One, pitched roof |
| Also shown on the plans | 8 ft ceilings | Laundry and hot water tank |
| Minimum lot it suits | Any lot that allows a garden suite | Any lot that allows a garden suite, since 55 m² is the small-lot maximum |
Each plan set has 13 sheets: a cover sheet, architectural floor plans, sections and elevations, mechanical sheets including a radon rough-in, and general notes, all drawn to the 2024 Ontario Building Code. The footprints are read from the floor plan drawings rather than stated by the City, so confirm the exact dimensions on the set you download.
The City also launched a materials list in November 2025, giving quantities for each construction phase so you can price the build with suppliers. It does not include prices.
What “pre-approved” covers, and what it does not
| Already reviewed | Still reviewed for your property |
|---|---|
| The building design: floor plans, elevations, sections and construction details | Site plan showing where the suite sits on your lot |
| Building Code compliance of the structure itself | Grading and drainage plan |
| No designer needed for the building drawings | Zoning: size, height, setbacks and lot coverage |
| Spatial separation: window and door sizes and positions near lot lines | |
| Water, sewer, electrical and gas servicing | |
| The fire access path from the street | |
| Tree removal, under a separate tree permit |
What you can change
You can choose exterior cladding (vinyl, wood, brick or stone), windows, doors and flooring. You cannot change the size or the layout, meaning the positions of walls, doors, windows and rooms. The notes on the plans say alterations to the drawings are not permitted and the City is not liable for rework costs. If you want a different size or a second storey, you need a custom design and a full review.
How to build a garden suite with a pre-approved plan
Step 1: Confirm your zone and lot
Garden suites are allowed in most detached and semi-detached zones (RL, RS, R12 to R14, R16, RM3 and RM7) and in some townhouse zones (RM5 and RM6) only on corner or through lots. RM7 lots need a detached or semi-detached house. Standard condominium townhouses cannot have one, and common-element condo townhouses need condo board approval. Use the City’s online zoning map and your property survey.
Step 2: Count your units
A lot can have up to two additional units: two inside the house, or one inside plus one garden suite. Only one garden suite is allowed per lot. If you already have a registered basement apartment, a garden suite would be your third and last unit. See our guide to registering a second unit in Mississauga for the basement route.
Step 3: Prepare the site plan and grading plan
These are the documents you still need a professional for. The site plan shows the suite, setbacks, the fire access path and servicing routes. The City recommends that a design professional prepare the grading and drainage plan, since a new structure changes how water moves across your yard.
Step 4: Apply through ePlans
Submit the site and grading plans, the Applicable Law Form and, where it applies, the Second Unit Registration Form. Do not upload the pre-approved drawings. Instead, name the model (studio or one-bedroom) in the description of work. Fees are paid after pre-screening. If the suite will share water and sewer with the house, include the Water Service Pipe Sizing Form.
Step 5: Get the permit and build
The City says pre-approved plan applications are expedited, but it does not publish a target. For comparison, its general second unit numbers are 7 to 10 business days for pre-screening and an average of about 10 weeks to issue. After the permit is issued you can book an optional kickoff meeting with Inspection Services.
Step 6: Inspections, address and registration
Book building inspections online and fire inspections by phone at 905-896-5908. Electrical and gas work follows Electrical Safety Authority and TSSA rules. The suite needs its own municipal address, and the City charges a small fee for it. Once final inspections are complete, the unit can be registered.
Mississauga’s garden suite zoning rules
| Rule | One storey | Two storeys |
|---|---|---|
| Floor area, lot 550 m² or less | 55 m² | Not available on most small lots |
| Floor area, lot over 550 m² | 10% of lot area, up to 100 m² | 10% of lot area, up to 100 m² |
| Height, sloped roof | 4.6 m | 6.8 m |
| Height, flat roof | 3.0 m | 5.8 m |
| Interior side setback | 0.6 m | 1.8 m |
| Rear setback | 1.8 m | 1.8 m |
| Street-side setback (corner lot) | 2.5 m | 4.5 m |
| Distance from greenlands or hazard zones | 5.0 m | 5.0 m |
- Location: the rear yard, or the street-side yard on some corner lots.
- Two storeys: the zoning table separates lots above and below 750 m² for two-storey suites, and through lots can have a two-storey suite up to 100 m². Confirm with the City before designing a two-storey suite.
- Lot coverage: you get up to an extra 10 per cent, which can only be used for the garden suite.
- Relative to the house: the suite cannot be taller than the house or cover more of the lot than the house.
- No upper deck: a second-storey balcony or deck is not allowed.
- Parking and driveways: no extra parking is needed, and the lot can only have one driveway.
- No home business inside the suite.
- It stays part of your property. Selling the suite separately would require a severance, which is a separate planning approval.
The fire access path
This rule decides more garden suite projects than any other. Firefighters must be able to walk from the street to the suite’s door along a hard-surfaced path at least 1.2 metres wide with 2.1 metres of clear headroom, and the walk must be 45 metres or less. A side yard narrowed by an air conditioner, a gas meter or a fence gate that is too low can block an otherwise good lot. Measure it before you spend anything.
Servicing
Water and sewer can be shared with the main house, sized with the City’s pipe sizing form, or brought in separately through the Region of Peel. Electrical and gas connections follow ESA and TSSA rules. Servicing is often the largest hidden cost, especially when the line has to run the length of a deep lot.
Fees and charges in 2026
| Item | Cost |
|---|---|
| Pre-approved plans | Free |
| Building permit | $18.99 per m²: about $760 for the studio and $1,044 for the one-bedroom |
| Permit refund | Refunded by cheque under the Gentle Density Incentive Program |
| Administration fee | $50, credited to the permit |
| New municipal address | About $77 to $82 plus HST; City pages show both $77.20 and $81.90 |
| Tree permit, if you remove a tree 15 cm or wider | $399.77, plus $139.72 for each extra tree |
| City, Region and GO development charges | Exempt under the Development Charges Act for one unit in an ancillary building |
| School board development charges | May apply; confirmed at permit review |
One City page says development charges “apply to” garden suites, while its incentive table and the provincial Development Charges Act exempt a suite in an accessory building when the house has no more than two units. Ask for the exemption to be confirmed in writing at permit review.
What a garden suite really costs to build
A garden suite is a full house in miniature: foundation, framing, roof, kitchen, bathroom, heating and new service lines. That is why it costs far more per square foot than a basement unit.
| Benchmark | Figure |
|---|---|
| GTA builder estimate, all in | $400 to $650 per sq ft |
| Pre-approved studio at that rate | About $172,000 to $280,000 |
| Pre-approved one-bedroom at that rate | About $240,000 to $390,000 |
| Servicing (water, sewer, electrical, gas) | $15,000 to $50,000, included in the range above |
| Toronto garden suites, median permit value | $180,000 (average $260,000, average size 82 m²) |
| Toronto industry interviews, real cost | Often $300,000 to $400,000 or more |
The free plans save you roughly the design fee, and the City’s materials list helps you get firm supplier quotes. The biggest variables are how far your services have to run, the soil and grading, and whether trees need to come down.
Paying for it
- CMHC-insured refinance: since January 2025 you can refinance up to 90 per cent of your home’s value after the suite is built, if that value is under $2 million, with up to a 30-year amortization. You or a close relative must live on the property, and short-term rentals are not allowed.
- Peel Region’s renovation loans are on hold, and the federal secondary suite loan announced in 2024 never opened.
- Lenders count part or all of the rent from a legal unit when you qualify. Our stress test guide shows how.
What a garden suite rents for
There is little published rent data for Mississauga garden suites yet, since so few have been built. GTA builders report $1,800 to $2,400 a month for a studio or one-bedroom suite. For comparison, the average asking rent for any one-bedroom in Mississauga was $1,998 in October 2026. A detached suite with its own entrance, yard space and no shared walls usually rents at the top of the range for its size.
At $2,100 a month, a $280,000 suite earns about 9 per cent of its cost a year before expenses, a slower payback than a basement unit. Many owners build garden suites for family, such as aging parents or adult children, where the return is measured differently.
Garden suite or basement apartment?
| Garden suite | Basement unit | |
|---|---|---|
| Typical cost | $170,000 to $400,000 | $45,000 to $130,000 |
| Time | Often 8 to 14 months (our estimate) | Usually 4 to 7 months |
| Free City plans | Yes, two designs | No |
| Privacy | Fully separate, no shared walls | Shared walls and ceiling |
| Natural light and ceiling height | Full windows, 8 ft ceilings | Limited by the basement |
| Uses yard space | Yes | No |
| Best for | Family members, higher rents, long-term value | Fastest payback |
You can have both, since the rules allow two additional units on one lot.
How Mississauga compares
- Toronto offers four pre-approved designs (studio and two-bedroom garden and laneway suites, 24 plan variants), and its plans are pre-checked for zoning as well as the Building Code. Toronto had 748 garden suite permit applications between 2022 and April 2025.
- Mississauga has also pre-reviewed two designs from the federal CMHC Housing Design Catalogue, a one-bedroom and a three-bedroom unit. They are free to use but are not pre-approved, so they go through full review.
- Uptake has been modest. By mid-2025 the City reported more than 100 inquiries and about 50 garden suite permit applications, and its first suite built from a pre-approved plan was completed in July 2025.
Who to contact
| Zoning and garden suite questions | 311, or 905-615-4311 from outside the city |
| Planning and Building | 905-615-3200, 300 City Centre Drive |
| Fire inspections | 905-896-5908 |
| Permit fee refund | housingincentives@mississauga.ca |
| Minor variances | Committee of Adjustment |
Questions owners ask
Are Mississauga’s pre-approved garden suite plans free?
Yes. Both the studio and one-bedroom plan sets are free to download and use.
How big can a garden suite be in Mississauga?
55 m² on a lot of 550 m² or less. On larger lots, 10 per cent of the lot area up to 100 m².
Do I still need a permit with a pre-approved plan?
Yes. You apply through ePlans with a site plan and a grading plan, and the City reviews zoning, servicing, spatial separation and the fire access path.
Can I change the pre-approved plans?
Only finishes such as cladding, windows, doors and flooring. The size and layout cannot change.
How much does a garden suite cost in Mississauga?
GTA builders estimate $400 to $650 per square foot all in, which puts the pre-approved studio at roughly $172,000 to $280,000 and the one-bedroom at $240,000 to $390,000.
Do I pay development charges on a garden suite?
City, Region and GO charges are exempt for one unit in an accessory building when the house has no more than two units. School board charges may apply.
Can I have a basement apartment and a garden suite?
Yes. A lot can have two additional units, so one inside the house and one garden suite is allowed.
Do I need extra parking for a garden suite?
No. Mississauga requires no additional parking for a garden suite.
Can I sell the garden suite separately?
Not without a severance, which is a separate planning approval. A garden suite is part of your property.
Sources
- City of Mississauga: Pre-approved garden suite plans (updated August 2026); studio and one-bedroom plan sets (June 2024); Additional residential units (January 2026); news releases of July 29 and November 17, 2025.
- City of Mississauga: Zoning By-law 0225-2007, Part 4 and Table 4.1.1.14, as amended by By-law 0174-2023; building permit fees, February 2026 to January 2027; Gentle Density table of incentives (April 2026); tree permit fees (August 2026); building permit time frames (June 2026).
- Development Charges Act, s.2(3.2); City of Toronto Garden Suites Review (May 2025) and pre-approved plans page (2026); Storeys (July 2025).
- Department of Finance Canada, secondary suite mortgage insurance changes (October 2024); Region of Peel; Zumper (October 2026); GTA builder cost estimates (2026).
This guide is general information, not legal, planning or building advice. Confirm the current rules for your property with the City of Mississauga before you design or build. HomeLife Landmark Realty Inc., Brokerage.