How Much Does a Garden Suite Cost in Toronto & the GTA?

Compact 1-Bedroom

$180,000 - $260,000

~400 - 600 sq ft

A simple single-storey one-bedroom suite. The most cost-effective option, especially with easy rear-yard access and short servicing runs. Ideal for rental income or a multigenerational space.

Standard 1-Bedroom+

$240,000 - $340,000

~600 - 800 sq ft

A more generous one-bedroom with a proper kitchen, living area, and upgraded finishes. The most common garden suite size for owners balancing comfort and budget.

Two-Bedroom / Two-Storey

$320,000 - $400,000+

~800 - 1,000+ sq ft

A larger or two-storey suite with multiple bedrooms and premium finishes. Higher cost reflects added structure, a second floor, and more complex mechanicals.

Hard Costs (the build)

The physical construction of the suite. This is usually 75 to 85 percent of the total and scales directly with size and finish level.

• Excavation and foundation
• Framing, roofing, windows, and exterior cladding
• Mechanicals — plumbing, electrical, heating, and ventilation
• Insulation, drywall, and interior finishes
• Kitchen, bathroom, flooring, and fixtures

Soft Costs (design & approvals)

The non-construction expenses needed to design, permit, and service the suite. These are estimates and vary by project.

• Land survey — around $2,000
• Architectural and design fees — roughly $10,000 to $15,000
• Structural and engineering work
• Building permits and municipal review
• Utility and servicing connections (water, sewer, hydro)
• HST on the project

Servicing Distance to the Backyard

Water, sewer, and hydro typically run from the street or the main house out to the suite. The further the connection has to travel across the yard, the more trenching, materials, and labour are required. Long servicing runs are one of the biggest hidden cost drivers.

Site Access

Crews and equipment need a way into the backyard. A wide side yard or rear lane keeps costs down, while a narrow gap between houses can mean hand-digging, smaller equipment, and craning materials over the home — all of which add to the budget.

Grading & Drainage

A flat, well-drained lot is straightforward. Sloped sites, poor drainage, or the need to manage stormwater can require retaining walls, fill, or grading work that adds cost before the suite is even framed.

Finish Level

The same footprint can be finished as a practical rental or a high-end living space. Cabinetry, flooring, tile, fixtures, and windows are where finishes swing the per-square-foot cost from the low end of the range to the top.

One Storey vs Two

A second storey adds structure, stairs, and often a more complex roof and mechanical layout. Two-storey suites cost more per project, though they can be efficient when your buildable footprint is limited.

Size, Height & Setback Limits

Every municipality limits garden suite size, height, and setbacks, and those limits shape what you can build. A City zoning review at the feasibility stage confirms your buildable envelope so the design — and the budget — start from reality.

Toronto

The City of Toronto permits up to four units on most lots citywide, and garden suites are well established. The Bill 23 development-charge exemption applies to qualifying units. Construction costs sit squarely in the GTA ranges above.

Mississauga

Mississauga's active Gentle Density Incentive Program offers grants-in-lieu of certain City fees for qualifying rental units, which can lower net cost. Caps and eligibility apply — confirm current details.

Hamilton

Hamilton's active ADU & Multi-Plex incentive program covers eligible costs for qualifying units in Hamilton, Dundas, and Stoney Creek, making it one of the more grant-friendly markets in the region. Confirm program caps.

Vaughan, Markham & the 905

Across the rest of the GTA, build costs track the ranges above. The Bill 23 development-charge exemption applies to qualifying additional residential units, which removes a fee that used to add significantly to cost.

Bill 23 Development-Charge Exemption

Municipal development charges, parkland dedication, and community-benefit charges are prohibited on qualifying additional residential units. Commonly cited savings run roughly $20,000 to $60,000 per unit (estimate) — a fee that used to be a major line item.

Multigenerational Home Renovation Tax Credit

A refundable federal credit on up to $50,000 of eligible costs to build a self-contained suite for a senior (65+) or an adult eligible for the disability tax credit. Worth up to roughly $7,000 to $7,500 depending on the filing year. One per lifetime.

Active Municipal Programs

Hamilton's ADU & Multi-Plex program and Mississauga's Gentle Density Incentive Program can cover or rebate eligible costs and City fees for qualifying units. Caps, deadlines, and eligibility apply — confirm current details before relying on them.

CMHC Refinance to Build

A CMHC-insured mortgage refinance for secondary suites is the realistic way most owners fund a garden suite today, letting qualifying owners borrow against improved home value with extended amortization. Eligibility rules apply.

Rental Income

A garden suite creates a long-term rental unit on land you already own, without buying a separate property. Actual rent depends on size, finishes, and neighbourhood — we never guarantee a figure, but income is the most common reason owners build.

Multigenerational Living

Many families build a garden suite for aging parents or adult children — private, self-contained, and steps from the main house. The Multigenerational Home Renovation Tax Credit can offset part of the cost in qualifying cases.

Added Property Value

A second dwelling and an income stream can both contribute to a property’s value, though the impact varies by market. For a full breakdown of the numbers, read our garden suite ROI & rental income guide.

Keep the Footprint Simple

A clean rectangular plan is cheaper to build than one with lots of corners, offsets, and roof complexity. Simple shapes use materials efficiently and frame faster, which lowers both labour and material cost.

Shorten Servicing Runs

Positioning the suite to minimize the distance water, sewer, and hydro must travel across the yard reduces trenching and connection cost. A feasibility review can identify the most cost-effective placement on your lot.

Start with Feasibility

A zoning review and feasibility assessment up front prevents expensive redesigns later. Knowing your size, height, and setback limits before drawings begin keeps the project on budget from day one.

Build the Incentives Into Your Budget

The Bill 23 development-charge exemption and active municipal programs can lower net cost meaningfully. Factor confirmed incentives in early — see our financing page — rather than treating them as a bonus.

Choose Durable Mid-Range Finishes

For a rental suite, durable mid-range finishes often beat premium ones on value. They cost less up front, hold up to tenants, and rarely change what you can charge.

Use a Proven Floor Plan

A refined, repeatable design carries less risk and less custom engineering than a one-off. Working from a plan that has been permitted and built before reduces both soft costs and surprises.