Detached Garage Kits: Costs, Sizes and Permits in Canada

A detached garage kit is a pre‑engineered, stand‑alone building you assemble on a separate foundation from the house. It suits homeowners who want flexible placement, more privacy for tools or hobbies, and fewer fire‑separation constraints than an attached build. The biggest trade‑off is convenience: you’ll walk outside and trench for services (power, lighting, heat) instead of tying in through a shared wall. See our overview of prefab garage styles for context on structures and finishes: prefab garage styles.

What size detached garage fits two cars and a small shop?

Common footprints run from 18×24 (tight two‑car) to 30×40 (room for vehicles plus storage or a work bay). For everyday comfort:
– Interior width: plan 10–12 ft per vehicle. A 24 ft exterior width allows two 9 ft doors and 24–30 in clearance each side for door swing.
– Depth: 22–24 ft lets you park most pickups with space for a bench; 26–30 ft adds snowblower or bike storage.
– Door sizing: two 9×7 doors suit cars; 10×8 helps with trucks and roof racks. Leave 12–18 in between doors for trim and structure.
– Height: 9–10 ft wall height clears garage‑door tracks and tall racking; confirm overhead door radius against truss type.
– Access: keep 36 in clear beside at least one bay for a man door; allow 36–48 in in front of a workbench.
If you want a balanced two‑car with elbow room, many owners land on 24×30; see a typical steel option here: 24×30 C-Channel Prefab Garage Kit.

Permits, setbacks and trenching a detached garage in Canada

You’ll need a building permit almost everywhere. Zoning sets your setbacks (how far from side/rear lines), maximum height, and lot coverage (total building footprint allowed). These rules vary by municipality—check your local by‑law before you pick a size or site. Expect foundation requirements to reference local frost depth; many detached garages use a slab‑on‑grade with thickened edges, sized by a designer or engineer to your soil and snow load.

Services run in the ground from your house or meter to the garage. Plan a trench route that avoids trees and utilities, and contact your provincial locate service before you dig. Electrical work requires a permit and inspection; a sub‑panel sized for present and future loads (door openers, heat, EV, compressors) is typical. Your authority having jurisdiction will specify burial depth, conduit type, and clearances from gas/water lines. When you’re ready to compare structures and specs, you can browse all DIY garage kits.

Detached Garage Kits: Costs, Sizes and Permits in Canada Gallery

Planning and building: foundations, permits, climate loads and the choices to make

A detached garage kit is popular because it separates vehicle traffic, noise and fumes from the home, offers siting flexibility, and can be added to lots where an attached garage isn’t practical. Common footprints range from 18×24 for two compact cars to 30×40 for vehicles plus a shop. Before you price anything, confirm what your lot can accept and how you’ll service it.

Do I need a permit for a detached garage kit?

Most municipalities require a building permit for a detached garage; some set different thresholds for size or height, and separate approvals may apply for electrical service or driveway changes. Start with your local planning and building departments and this overview of garage permit requirements in Canada. The National Building Code of Canada (NBC) informs structural and life‑safety rules nationally, but provinces adopt and amend it, and municipalities set zoning such as setbacks, lot coverage and maximum height—those numbers are local, not national. For technical reference, the NBC is published here: National Building Code of Canada publications.

What foundation is best for a detached garage?

For most detached builds, a reinforced concrete slab‑on‑grade with thickened edges (monolithic slab) is the straightforward, frost‑resistant choice and suits slab heat or a car lift. In colder regions or on sloped/poor soils, designers may specify a shallow frost‑protected slab, strip footings with a slab, or engineered piers with grade beams. The correct option depends on geotechnical conditions, frost depth, drainage, and the loads of your structure and vehicles—your engineer will design to the applicable provincial code based on the NBC.

How do snow and wind loads affect my design?

Roof pitch, truss spacing, sheathing, and hold‑downs are sized to local design snow and wind loads set by code. Higher snow areas often favour steeper roofs, stronger trusses, and beefier headers over wide doors; coastal and prairie winds drive uplift and lateral bracing details, including anchor bolts and shear walls. Your quote should state the site design loads and the code edition used.

What will my lot allow, and how do I run power?

Confirm setbacks from property lines, maximum lot coverage, and driveway access with your municipality before picking a size like 22×24 or 30×40. Plan the service trench for power (and optional data/water): route, depth, conduit, and utility clearances are determined by your electrical authority and local rules. Call before you dig and show utilities on your site plan.

The mistake buyers make most often

Locking in a footprint and door layout before verifying zoning setbacks, lot coverage, utility locations, and snow/wind design loads. Solve those first; then finalize size, door heights, and wall/roof system.

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