Garage Cost Calculator

Garage Details

Cost Breakdown (midpoint)

How this estimate works

We multiply your garage's floor area by a base cost per square foot for the finish level you chose (default: $65 shell, $95 insulated, $135 finished — 2026 Canadian planning averages). Foundation and roof choices adjust the total: frost walls add cost for excavation and formed concrete walls below frost depth, while pier foundations save on concrete. A permit and design allowance is added, and the result is shown as a ±15% range to reflect typical quote spread.

Published 2026 figures for Canadian detached garages vary widely — some sources quote $35–$65/sq ft for the wood-frame structure alone, others $80–$150/sq ft all-in once foundation, electrical, and finishing are counted. Our defaults sit in the all-in band because that's the number people actually need to budget. If a contractor quotes you well outside it, the difference is usually scope, not a bad quote — check what's included before comparing.

What drives the number

Finish level is the biggest single lever — bigger than size, roof, or foundation. An unheated shell is a weatherproof box: structure, cladding, roof, a door. Insulating and wiring it roughly adds half again. Finishing and heating it can double the shell price, because at that point you're building a small conditioned building with a heat source, a vapour barrier, drywall, and an electrical load that may force a subpanel. Decide what you'll actually use the space for before you price it. "Insulated in case I want a shop later" is the most commonly regretted upgrade — and the most commonly regretted omission, depending entirely on whether "later" ever arrives.

Size behaves non-linearly. Permits, mobilization, excavator setup, and the crew's travel don't scale with floor area — they're much the same for a 12×24 as for a 24×24. That means the cost per square foot usually falls as the garage gets bigger, and a double is often better value per foot than a single. It also means shrinking a garage to save money returns less than people expect. Going from 24×24 to 22×22 sheds about 16% of the area but well under 16% of the cost.

Foundation choice is really a frost-depth question. A slab-on-grade is the cheapest path where it's permitted. A frost wall means excavating below the local frost line and forming concrete walls down to it — more excavation, more forms, more concrete, and often a second site visit. Whether you get the choice at all is up to your municipality and your soil, not your budget, so confirm before you assume the cheaper option. Piers cost least in concrete but rule out a slab floor, which makes them a poor fit for anything you'll roll a vehicle into. Our slab vs. frost wall guide works through the decision, and the Foundation Estimator prices each option with real quantities.

Roof geometry moves the number more than it looks like it should. A hip roof has more surface area and far more cut waste than a gable of the same footprint — we apply about +7%. A mono-slope is the cheapest to frame and sheath, at roughly −4%. If you want usable storage overhead, that's a truss decision made now, not later; the Attic Space Calculator shows what a given roof actually yields.

Site conditions are the genuine wildcard, and the reason two identical garages on two lots don't cost the same. Rock, a high water table, soft or filled ground, poor access for a concrete truck, or a slope needing retaining all add cost that no per-square-foot average can predict. This is the single biggest reason a quote comes in above an estimate.

Where you are matters, and by more than most national averages admit — regional labour rates and material freight produce real spreads between provinces and between metro and rural areas within the same province. The regional selector at the top of this page applies a multiplier for exactly this reason.

What this estimate does not include

This is the part that turns a good budget into a bad surprise. The figure above covers the building. It does not cover most of what's needed to make the building usable:

• Running power from the house. Trenching and cable from your existing panel to the garage is a separate job, commonly in the $2,500–$5,000 range, and considerably more on a long rural run. The "insulated + wired" finish level covers wiring inside the garage, not getting power to it.
• Development charges. These are separate from the building permit fee, levied by some municipalities at the permit stage, and confusing the two is one of the more expensive planning mistakes in Canadian residential construction. Ask your municipality specifically whether an accessory structure triggers them.
• The driveway and apron. Getting a vehicle to the garage door is its own line item — price it with the Driveway Cost Calculator.
• Site preparation beyond ordinary excavation: tree and stump removal, imported fill, rock breaking, or regrading. Our Fill & Gravel Calculator handles the material volumes.
• Demolition of an existing structure on the footprint, including disposal.
• Surveys and drawings beyond the modest design allowance, if your municipality requires a surveyed site plan — which many do for accessory structures near property lines.
• Landscaping restoration after the equipment leaves. Heavy machinery on a finished yard is not a cosmetic problem.
• Fit-out: door openers, shelving, workbenches, hoists, floor coatings, water service.

A reasonable planning habit: take the estimate above, then ask each contractor quoting the job which of these lines they've included. Quotes that look far apart are usually quoting different scopes, and the cheapest one is frequently the one that excluded the most.