What is included in a garden suite construction price?
A published price is only comparable once you know what it covers. The table sets out each source as its publisher describes it. All four are builders, so these are their own sales figures, not independent market data.
| Publisher and date | Published price | Scope included | Exclusions or items to confirm |
|---|---|---|---|
| Hutly (opens in a new tab), custom garden suite builder; page modified April 21, 2026 | $360 to $500 per sq ft, depending on configuration and finish: one floor $430 to $500; one floor with basement $390 to $450; two floors $375 to $420; two floors with basement $360 to $390. “Typically” $400 to $450. Size example: 650 sq ft in Toronto, $285,000. | Construction of a custom (not prefab) suite. The page says the range “includes the full scope of building” a code-compliant secondary dwelling, and that access, servicing connections and structure affect the final cost. | Not stated: HST, design and engineering, permits and fees, landscaping. Ask which of these the rate covers. |
| BVM Homes (opens in a new tab), prefab garden suites in Toronto; no date shown, checked October 2, 2026 | One-bedroom, about 480 sq ft: $201,000 to $253,000 plus HST. Bachelor, about 320 sq ft: $150,000 to $202,000 plus HST. | One-bedroom, itemised: design and permitting $6,000 to $8,000; utilities and foundation preparation $30,000 to $50,000; construction $165,000 to $195,000 (by finish level). All plus HST. | Excludes Committee of Adjustment fees and City fees other than the building permit fee. Utilities and foundation depend on existing services and the distance from the main house. Not stated: landscaping and restoration. |
| Atella (opens in a new tab), pre-engineered garden suites; no date shown, checked October 2, 2026 | Atella One, 408 sq ft: $155,000 plus installation. Models range from $99,000 (310 sq ft) to $330,000 (1,086 sq ft), each “plus installation”. | The same page lists permit preparation and fees, surveys, engineering and architectural stamps, excavation and foundation, utility connection, assembly and appliances as “included in our price”, and describes suites as “fully installed for less than $200k”. | The model prices say “plus installation”, so ask for the installed total for your lot. The page says unique site conditions, such as tree removal or garage demolition, are identified and priced in advance. HST not stated. |
| Lanescape (opens in a new tab), Toronto laneway and garden suite builder; June 5, 2024 | Under 950 sq ft: $600 to $650 per sq ft plus HST. 1,000 to 1,500 sq ft: $400 to $500 per sq ft plus HST. | Cost “to build”, from Lanescape’s historical data on Toronto projects by it and other builders. The article covers laneway and garden suites without separate garden suite figures, and calls the data limited. | Excludes contingencies, builder’s risk insurance, service connections through the existing house, upgrading incoming services, appliances, window coverings and landscaping. |
Figures as published by each source; not adjusted for inflation or combined. Two items on these pages are not used: Hutly’s itemised 650 sq ft breakdown, whose lines do not add up to its stated total, and BVM’s two-bedroom total, which differs from the sum of its own components.
Two patterns are worth noticing. Smaller suites cost more per square foot in the sources that publish rates by size: Lanescape says trades have minimum start-up costs and many components are the same whatever the size. And the gap between packages is often scope rather than price: BVM’s construction line is one of three lines in its total.
These are builder prices. The Toronto garden suite permit page shows a different kind of figure: construction values declared on City building permits. Those records do not consistently show whether design, servicing or fees were included, so a permit median is not a total project budget and is not a like-for-like comparison with the prices above.
Which backyard conditions change the budget?
No published price has seen your backyard. Five conditions are worth establishing before you ask for quotes, because each one changes what a contractor has to price. Lanescape notes that tight lots, limited access and overhead wires can significantly raise costs in Toronto.
- Main house
- Proposed garden suite
- Service route (one possible route for water, sewer and electrical)
- Access route for workers, materials and equipment
- Tree, and the area around it where digging, storage or equipment can harm it
- Disturbed ground that may need restoring
| Condition | What to establish | What the quote should specify |
|---|---|---|
| Servicing route | Where water, sewer and electrical leave the main house, and the path to the suite. The City says garden suite water and sanitary services are intended to connect from the main house (City Planning (opens in a new tab)). Plumbing for one unit may not run in or under another unit unless it is in an accessible space such as a tunnel or pipe corridor (Toronto Building (opens in a new tab)), and connecting to the main house’s services can count as a material alteration of it (City (opens in a new tab)). Note the size of the incoming water service and the electrical panel’s capacity. | The route and length assumed; any work inside the main house; panel or service upgrades; and whether a new or larger City connection is excluded. The City installs only the part on public land; work on your lot is the owner’s responsibility (Toronto Water (opens in a new tab)). |
| Access for equipment and materials | The clear width of the side yard or other route from the street, and what narrows it: gates, fences, steps, meters, overhead wires. Whether any access would cross a neighbour’s property. The fire access route is a separate requirement, covered in the comparison below. | How materials, excavation equipment and concrete reach the rear yard; whether anything is carried by hand or lifted over the house; who arranges any neighbour agreement; and how fences, paving and the house are protected. |
| Foundation and ground | A current survey, the slope of the yard, and whether you want a basement. A garden suite basement counts toward its interior floor area (City Planning (opens in a new tab)). Hutly publishes different rates for suites with and without a basement, and BVM says it discusses foundation type to reduce risks such as tree roots. | The foundation type assumed; excavation and soil removal; and what happens if ground conditions differ from that assumption: an allowance, a fixed price or a written change order. |
| Trees | Trees on your lot, your neighbours’ lots and the street near the suite, the service route and the access route. A tree on private property 30 cm or more in diameter, or any street tree, is protected; a garden suite should not result in removing a healthy protected tree, and a Tree Declaration Form goes with every building permit application (City Planning (opens in a new tab)). Trenching, storing materials and driving equipment over roots can injure a tree (City (opens in a new tab)). | Who arranges an arborist report (opens in a new tab) if one is needed; tree protection during construction; and any change to the design, foundation or service route made to protect a tree. |
| Restoration | What the service trench and the access route cross: lawn, garden beds, paving, fences. | Whether the price covers only backfilling and grading, or also replacing surfaces, fencing and planting. Lanescape’s published rates exclude landscaping. |
No source gives a standard cost or share of the budget for any of these conditions, so this guide gives none.
Does a prefab garden suite price include installation?
Not always, and “prefab” covers different products. BVM Homes (opens in a new tab) distinguishes modular suites, built off site and craned into the backyard, from its own pre-fabricated suites, which arrive as panels and are assembled on site; it says panels suit Toronto’s tight access. The two published prefab prices show why the headline figure needs reading:
- BVM Homes gives construction ($165,000 to $195,000 plus HST for its one-bedroom) as one line, then adds design and permitting and “utilities and foundation preparation” to reach its total.
- Atella lists each model “plus installation”, while the same page (opens in a new tab) says permits, surveys, foundation, utility connection and assembly are included in its price. Ask which figure your contract price is, and get the installed total for your lot in writing.
Prefab is not automatically cheaper. Lanescape, which builds on site, writes that prefab units of a comparable size “can often cost more than traditionally built structures for properties in Toronto” (June 2024 (opens in a new tab)). Prefab sellers argue for speed and price certainty. Neither view has seen your lot. Whatever the system, ask whether the price includes:
- Delivery to your property, and how the parts or modules reach the rear yard.
- Lifting. Whether a crane is needed, and who arranges and pays for it.
- Foundation, including excavation and soil removal.
- Connections for water, sewer and electrical, from the main house to the suite.
- Site work and restoration along the access and service routes.
- Finishes and appliances, and which choices change the price.
- Design, permits and City fees.
- HST, on the total and on any allowances.
Garden suite vs laneway house: what changes the budget?
The two are different City permissions with different access rules. If your lot abuts a public lane, the City directs you to the laneway suite rules instead (City Planning (opens in a new tab)). The differences that matter for a budget are about the lot, not the building:
| Budget factor | Garden suite | Laneway house |
|---|---|---|
| Lot condition | Usually in the rear yard, not on a public lane. | The lot abuts a public lane, and the suite sits beside it. |
| Fire access route | From the street the house faces, through the property: at least 1.0 m wide (0.9 m if sprinklered) and 2.1 m high, up to 45 m to the suite entrance, or up to 90 m with an extra fire-safety measure. The path can be on your lot or rely on a limiting distance agreement with a neighbour (City (opens in a new tab)). | At least 0.9 m wide and 2.1 m high, up to 45 m from the street, or up to 90 m through the lane with an extra fire-safety measure (City (opens in a new tab)). |
| Construction access | Without a lane, workers, materials and equipment come from the street side, through or around the property. | Check whether the lane can take deliveries and equipment. |
| Servicing | Water and sanitary services are intended to connect from the main house (City Planning (opens in a new tab)). | Services reach the rear of the lot from the street, through or around the main house. |
| Quoted scope | Same questions for both: design, servicing, site work and restoration, City fees, HST and allowances. | The laneway house cost guide has its published rates and City fees. |
For either type, the extra fire-safety measures are automatic sprinklers, or upgraded fire-protection construction, each with an exterior strobe light and a smoke alarm system. Both are items to price where they apply.
Neither type is always cheaper. Kildrin publishes separate permit samples for garden suites and laneway houses, but the records do not show whether size, access or scope explains any difference between them, so compare quotes for your own lot rather than the two medians.
What should you confirm before requesting a quote?
A contractor can only price what they can see. Have these ready, and ask for each item to be marked as included, an allowance (an amount set aside for work whose final price is not settled) or excluded:
- Proposed size and use. Floor area, storeys, whether you want a basement, the number of bedrooms and who will live there. Rates differ with storeys and basements in Hutly’s table.
- Site access. The clear width of the side yard and the length of the route from the street to the proposed suite entrance, checked against the City’s fire access rules (opens in a new tab).
- Servicing. Where services leave the main house, the water service size, the panel capacity, and what the route crosses. The backyard diagram shows what to note.
- Trees. Location and approximate size of trees near the suite, the service route and the access route, including on neighbouring lots and the street.
- Design and approvals. Who prepares the drawings, a custom design or a pre-approved plan (opens in a new tab) (whoever uses one takes responsibility for the design); who applies for the Zoning Applicable Law Certificate ($644.38 for a new garden suite, effective January 1, 2026 (opens in a new tab)) and the building permit ($18.56 per m² plus $56.33 per new unit (opens in a new tab)); and whether a minor variance may be needed.
- Inclusions and exclusions. HST, appliances, window coverings, landscaping and restoration, and any City fees beyond the permit.
- Unresolved allowances. Ground conditions, service upgrades and tree protection: how each will be priced if it changes. The quote comparison guide covers allowances, exclusions and change orders.
- Incentives. Check any grant or loan a sales page mentions. The federal Canada Secondary Suite Loan Program will not be implemented (Budget 2025 (opens in a new tab)), and the City exempts additional units such as garden suites from development charges (City Planning (opens in a new tab)).
Kildrin can pass your request to one contractor who works in your area. A quote for your property is the only way to price its site, services and access.
Requesting a quote is free for homeowners. Participating contractors pay Kildrin for eligible introductions.