LYON Building a detached garage in Calgary: permits, setbacks and cost
It is a small building, and the City inspects it like one.
Last reviewed 2026-09-03 · Calgary, Alberta
A detached garage looks like a shed with ambitions. It gets inspected like a building, and what catches people is where it sits and what it sits on.
When a detached garage needs a permit in Calgary
A building permit is required for any accessory building greater than 10 m², which is about 107 sq ft. Every real garage is over that. Depending on your address, size and location, a development permit may be needed as well.
Setbacks: where it can actually go
An accessory building cannot sit in the front setback. Beyond that:
- 0.6 m from a rear property line shared with a lane or another property
- 1.2 m from a side property line shared with a street
- 0.6 m from a side property line shared with another property
These are the numbers that decide whether the garage you have in mind fits the lot. It is worth confirming them against your own property before you fall in love with a size.
The 55 square metre rule, and the frost myth
A detached garage under 55 m² and no more than one storey can sit on wood mudsills or a 100 mm concrete slab, as long as it is not masonry. It does not automatically need footings driven below the frost line, whatever anyone tells you.
Above 55 m² (about 592 sq ft) the picture changes: if the slab is bigger than that and there is no concrete foundation 1.2 m below grade, the slab has to be designed by a professional engineer.
A house foundation and a garage slab are different structures with different rules. The point is worth knowing before you accept, or reject, a quote on the basis of how deep it digs.
The 400 square foot line that catches people
Permit fees for accessory buildings step up in size brackets, and the step sits at 400 sq ft. A 20×20 garage is exactly 400. A 22×22 is 484, and a 24×24 is 576.
So most double garages fall into the higher bracket, and the jump is not small. If a quote treats permits as a rounding error on a 24×24, it has not read the schedule. Ask whether the permit cost in your quote reflects the bracket your garage is actually in.
WHERE THIS COMES FROM
Written by Lyon Homes Ltd., Calgary. General guidance from our own jobs. Requirements vary property to property, so we confirm yours at the site visit.
Book a site visitQuestions people ask
Do I need a permit to build a detached garage in Calgary?
Yes. A building permit is required for any accessory building greater than 10 m², about 107 sq ft, which covers every garage. A development permit may also be required depending on your address, and the size and location of the build.
How far does a garage have to be from the property line in Calgary?
Generally 0.6 m from a rear property line shared with a lane or another property, 1.2 m from a side property line shared with a street, and 0.6 m from a side property line shared with another property. Accessory buildings are not permitted in the front setback.
Does a detached garage in Calgary need frost footings?
Not necessarily. A detached garage under 55 m² and no more than one storey may be supported on wood mudsills or a 100 mm concrete slab, provided it is not masonry construction. Above 55 m² without a foundation 1.2 m below grade, the slab must be engineered.
Book a free site visit.
We see every property in person before quoting. You get a fixed price in writing, for a scope you can read line by line.