Garden Suite Kits in Ontario what’s in the box, and what never is
A kit or prefab price covers the building. It does not cover the hole in the ground, the pipes to the house, the permit drawings, the heat loss design or the crane. On most backyard projects, the part that isn’t in the box costs as much as, or more than, the box.
Published starting prices
Sellers named in the table below. Prices are what each seller or city page showed in October 2026. We are not paid by any of them and this is not an endorsement.
An Ontario garden suite kit or prefab unit gets you the building shell or a finished module, from about $60,000 to $190,000 in published prices. It never includes the foundation, water, sewer and hydro connections, permit drawings, site plan, heat loss and HVAC design, the crane, or your yard repair. Budget those separately before you sign a deposit.
A Kit Is Not a Garden Suite. It’s most of one building.
We’ve built a lot of houses since 1979, and the conversation about kits always starts the same way. Somebody shows us an ad with a nice photo and a price ending in 999. Then we ask where the water is coming from.
That’s not a knock on kits. Factory building can be tighter, faster and drier than framing in November rain. The problem is the word “kit” covers everything from a pile of pre-cut cedar to a fully finished house on a truck, and the ad rarely says which one you’re looking at.
So before anything else, figure out which of these three you’re buying.
1. Pre-cut or shell kit
Lumber, siding, roofing, windows and doors cut to fit, delivered flat. You or your crew assemble it. Insulation, wiring, plumbing and finishes are often not in the price.
Watch for: many of these are sold as cabins, bunkies or studios, not as legal dwellings.
2. Panelized kit
Walls, floors and sometimes roof come as factory-built panels. Faster to close in. You still need a foundation, a crew, trades and all the interior work.
Watch for: who supplies the engineering for your snow load and your town.
3. Finished modular unit
Built and finished in a factory, trucked in and lifted onto your foundation. Plumbing, wiring and finishes mostly done. You connect it to services.
Watch for: delivery access, crane cost and the CSA certification label.
What Ontario Sellers Actually Publish and what their own pages say is extra
We pulled these from each seller’s page or the city page that lists them. Most prefab companies don’t publish a price at all, and the ones that do rarely publish what’s excluded. These are examples, not recommendations.
| Seller / product | Type | Size | Published price | What the page says about extras |
|---|---|---|---|---|
| Summerwood Canmore bunkie | Pre-cut kit (pre-assembled option) | 12 x 12 ft (144 sq ft) | US$11,502 on sale (US$17,695 regular), pre-cut | Freight quoted separately. Sold as a cabin or bunkie, not described as a dwelling |
| 3D Prefab Versa 192 (Salford, ON) | Factory-built unit | 192 sq ft, one bedroom, kitchenette, bath | $59,999 | Exclusions not listed. Site prep, permitting coordination and utility connection appear as process steps, not as included items |
| Modular Homes 400 (Toronto) | Finished modular, CSA A277 / Z240MH | Seven compact backyard models | Backyard suites from $96,244 | “Site work, foundation, delivery, and permits are additional” |
| Backyard Homes Canada Beech | Pre-approved design (St. Catharines) | 37 m², one bedroom | $129,999 + HST | City page says price is for “the construction of the unit”; site work and permits not mentioned |
| Backyard Homes Canada Maple | Pre-approved design (St. Catharines) | 54 m², two bedrooms | $189,999 + HST | Same as above |
Last checked October 2026 · Sources: seller pages linked in the table and City of St. Catharines
Older numbers you’ll see quoted. A February 2024 Storeys article reported BLOKK studios from $85,000 for a basic model and CABN one-bedroom units from $249,000, with CABN saying “clients are responsible for their site preparations and permitting.” Neither price was published on the companies’ current pages when we checked, so ask for a dated written quote.
Notice the bunkie on the top line. A 12 x 12 building is 13.4 m², which is already over the 10 m² size where Ontario starts asking for a building permit even for a shed. Turning it into a legal place to sleep, cook and use a toilet is a whole different set of rules. More on that in garden suite vs bunkie vs tiny home.
The Six Things No Kit Includes and what they cost
The ranges below come from one published 2026 Canadian cost guide, RenoQuotes. They are not our quote. Your lot can land you outside them in either direction.
| Item | Why the kit can’t include it | Published 2026 range |
|---|---|---|
| Foundation | Depends on your soil, frost depth, slope and the module’s bearing points. Has to be designed for your lot. | Helical piles $8,000 to $12,000; insulated slab $15,000 to $25,000 |
| Servicing | Distance to the house, sewer depth, water main size, hydro capacity. All site-specific. | Excavation and underground plumbing $12,000 to $22,000; electrical and utility work $6,000 to $12,000 (400 sq ft example) |
| Permits, site plan, drawings | Your town reviews your lot, not the factory’s catalogue. | $3,000 to $7,000 for permits, plans, surveys and review fees |
| HVAC and heat loss design | Ontario needs a heat loss and duct or equipment design for the house as built on your site. Orientation and climate zone matter. | Not priced in the guide; get a quote |
| Crane and delivery | Your street, wires, trees and side yard decide this. | Crane over the house $5,000 to $12,000 for a day; transport not priced |
| Finishing | Shell kits leave the inside to you. Even modulars leave the joints, steps, decks and landscaping. | Interior finishes and kitchen/bath $20,000 to $35,000 (400 sq ft example) |
Last checked October 2026 · Source: RenoQuotes, garden suite cost in Canada 2026
Buying a kit or prefab? Get the permit side quoted before the deposit.
Our Prefab/Kit Permit Pack covers the foundation interface, site plan, heat loss and HVAC, and septic on rural lots, from $1,999.99 + HST. Send the model sheet and your survey for a fixed quote.
Run the arithmetic before the salesperson does
Take the $96,244 modular starting price above and add only the low end of each published range: a $15,000 slab, $12,000 of excavation and underground plumbing, $6,000 of electrical, $3,000 of permits and plans, and a $5,000 crane day. That’s $137,244 before delivery, HVAC design, steps, a deck or a blade of grass. Use the high ends and you’re at about $174,000.
That’s an illustration with someone else’s numbers, not a quote. The point is the shape of it. The box can be half the bill.
Where Kit Buyers Get Burned one item at a time
Foundation
The kit has bearing points. Your foundation has to meet them exactly, sit below frost or be frost-protected, and suit your soil. A factory drawing that says “by others” means you. Read our foundation options page before you pick piles because they’re cheapest; on wet or clay sites they’re not always the best answer.
Servicing
Water, sewer and hydro to a building 15 m behind the house means trenching across the yard, often under a driveway or patio, and sometimes a hydro panel upgrade or separate meter. On a rural lot add septic capacity, which is a separate design through SepticReplacement.ca. See servicing costs.
Permits
The seller’s drawings show the building. Your town still wants a site plan, a grading plan, designer forms and often a tree declaration. Some sellers “coordinate” permits; ask exactly what that means and who signs the forms.
HVAC design
A heat pump picked from a brochure isn’t a design. Ontario permit reviewers expect a heat loss calculation and an equipment and ventilation design for the unit. We use OntarioHeatLoss.ca for BCIN-stamped designs.
Crane and delivery
A module needs a truck path and a crane spot. Overhead hydro wires, a narrow side yard and the neighbour’s maple decide whether you lift over the house. Toronto even asks for an overhead electrical conductors declaration. Get the lift plan before you sign.
Finishing
Shell kits stop at the outside walls. Modulars still need the marriage line, exterior steps, a landing at the door, eavestroughs, grading back to the suite and yard repair. None of that is glamorous and all of it is billable.
What the Inspector Looks For on a kit or prefab
Inspectors don’t care where the walls were built. They care whether the finished building meets the Ontario Building Code where it stands. A few things come up again and again.
- Factory certification on modules. Finished modules should carry a CSA A277 certification label, which covers the factory part. Your town still inspects the foundation, the connections and the site work.
- Drawings for Ontario, not somewhere else. A kit designed for a warmer place or another code needs to be checked for Ontario snow loads, energy rules and the climate zone you’re in.
- Footings before anything sits on them. On a site-assembled kit, expect the usual inspections: footings, framing, plumbing rough-in, insulation and vapour barrier, and final.
- Anchoring and the sill. How the building is fastened to the foundation, and that the sill is protected from moisture.
- Spatial separation and fire access. Distance to lot lines and the house affects how many windows you can have and what the walls must be. The path from the street has to be clear.
- Grading at final. Water has to run away from the suite and not onto your neighbour.
If the seller tells you the inspector “won’t need to see” something, that’s the thing the inspector will want to see.
Ten Questions to Ask Any Kit Seller in writing
A good seller answers these without blinking. If you get a pause and a “we’ll figure that out later,” that’s your answer too.
Is this sold as a dwelling or as an accessory building?
Cabins and studios can’t always become a legal suite without real changes to insulation, plumbing, ceiling height and fire separations.
What exactly is in the price, line by line?
Windows, doors, insulation, wiring, plumbing fixtures, kitchen, flooring, HVAC equipment. Get the list.
Are the drawings ready for an Ontario permit, and who signs them?
Ask who holds the BCIN or engineering seal and whether it’s for Ontario.
Is a foundation drawing included, or just loads?
Bearing points and loads are not a foundation design for your soil.
Is a heat loss and HVAC design included?
If not, budget for it. You’ll need it for the permit.
What does delivery cost, and how big is the truck?
Walk the route from the street to the pad. Measure the side yard.
Is a crane needed, and who books it?
Ask for the lift weight and the crane size they assume.
Who connects water, sewer and hydro?
Usually you. Get it in writing either way.
What’s the warranty, and who honours it?
Factory warranty on the box versus your contractor’s warranty on the site work. Know where one ends.
What’s the deposit, and when is it refundable?
If the town says no, or the lot needs a minor variance, can you get your money back?
Builder’s tip. Get your lot checked before you pay a deposit, not after. If the suite you love needs a minor variance to fit, that’s months of delay while your deposit sits in someone else’s bank account.
When a Kit Makes Sense and when it doesn’t
A kit or modular unit makes the most sense on a flat lot with good truck or crane access, services close by and a design you’re happy to take as drawn. That’s a lot of conditions, and plenty of Ontario lots meet them.
It makes less sense on a sloped lot, behind a house with a 1.2 m side yard and power lines overhead, or when you need the suite shaped around a tree, a view or a parent’s wheelchair. Then the savings at the factory get spent on the site. Our prefab vs custom page goes through the trade-offs, and ICF garden suites covers the build we do most.
If you’re in Simcoe County or around Georgian Bay, ICFhome.ca builds garden suites start to finish, and Georgian Bay Siteworks handles site work there, including for prefab buyers who need the pad and trenches ready.
Find out what your yard adds before you buy the box.
Our $399 + HST Garden Suite Feasibility Report looks at zoning, setbacks, fire access, servicing and delivery access on your lot, in 48 hours. The fee is credited toward permit plans or a build.
Garden Suite Kits: straight answers
How much does a garden suite kit cost in Ontario?
Published prices we found in October 2026 run from $59,999 for a 192 sq ft factory unit, to backyard modular suites from $96,244, to $129,999 plus HST and $189,999 plus HST for two designs listed by St. Catharines. Small cabin kits sold as bunkies start lower but are not dwellings. None of those prices includes foundation, servicing, permits or crane work.
What is not included in a prefab garden suite price?
Almost always: the foundation, water, sewer and hydro connections, the site plan and permit forms, the heat loss and HVAC design, delivery, the crane, and the finishing outside the walls such as steps, grading and landscaping. One Toronto modular seller states plainly that site work, foundation, delivery and permits are additional. Assume the same for any seller until they put it in writing.
Do I need a building permit for a garden suite kit?
Yes. Any building used as a dwelling needs a building permit in Ontario, whether it came on a truck or was framed on site. Even a plain shed over 10 square metres needs one. Your town will want a site plan, grading plan and designer forms on top of the seller’s drawings.
Can I turn a bunkie or cabin kit into a garden suite?
Sometimes, but it’s rarely cheap. A legal suite needs proper insulation and energy compliance, a kitchen, a bathroom tied into approved services, ceiling heights, smoke and CO alarms, fire separations where needed and a heating design. Most cabin kits are sold for seasonal or accessory use. Ask the seller whether the drawings can be stamped for an Ontario dwelling before you buy.
How much does a crane cost to set a prefab garden suite?
One 2026 Canadian cost guide puts a crane lift over the house at $5,000 to $12,000 for a day where there’s no driveway or side yard access. Wires, trees and the crane size needed for the module weight all move that number. Get the lift weight from the seller and a quote from a crane company before you commit.
Is a kit cheaper than a custom-built garden suite?
The building usually is. The total often isn’t by as much as the ad suggests, because foundation, servicing, permits and site work cost about the same either way. Kits save the most on easy lots with good access and a design you accept as drawn. On tight or sloped lots the savings shrink fast.
What should I look for on a modular unit’s paperwork?
Ask for the CSA A277 factory certification for the modules, drawings suitable for an Ontario permit with the designer’s or engineer’s credentials, foundation loads and bearing points, and the heat loss and HVAC information. Your town inspects the foundation, connections and site work even when the factory part is certified.