Do I need a permit to build a sauna in my backyard?

Plan on an electrical permit for the heater circuit. Whether you also need a building permit depends on the sauna's floor area and your city's threshold, which is commonly between 10 square metres (107 sq ft) in Canada and 120 to 200 sq ft in US cities. Setbacks apply either way. Confirm with your local building department.

Do I need a permit for an indoor sauna?

The heater's 240 V circuit needs an electrical permit. Building new walls or finishing a basement for it usually needs a building permit too, and a shower beside it adds plumbing. Your local building department can tell you which apply to your project.

Does a small outdoor sauna count as a shed?

Not always. Trent Lakes, Ontario advised that a sauna over 10 square metres needs a building permit because it is not a storage building, and many shed exemptions apply only to buildings with no electrical connection. A wired sauna often falls outside them.

Who issues an electrical permit for a sauna?

In the US, your city or county building department. In Canada it depends on the province: the Electrical Safety Authority in Ontario, Technical Safety BC in British Columbia, and the city or county permit office in Alberta.

Do I Need a Permit for a Sauna? US and Canada

Plan on an electrical permit. A traditional sauna heater runs on its own hardwired 240 V circuit, and new circuits need a permit or notification almost everywhere we checked, in the US and Canada.
Whether you also need a building permit depends on where the sauna goes and how big it is. Outdoors, the line is usually a floor area between 10 square metres (107 sq ft) and 200 sq ft, set by your city or county.
Indoors, new walls or finishing a basement usually bring a building permit. A shower adds plumbing, and a wood stove brings its own rules.
The rules change from one city to the next. Confirm with your local building department and a licensed electrician before you build.

The electrical permit: plan on it.

A traditional electric heater is wired on its own dedicated 240 V circuit. That is new electrical work, and new circuits are the most consistently permitted part of any sauna project.

In the US, the model residential code requires a permit to install or alter an electrical system, and its short exempt list covers only minor work such as replacing a breaker like for like. A new 240 V circuit is not on it. Each state or city adopts and amends the code, so your local building department issues the permit.

In Canada it is provincial. Ontario's Electrical Safety Authority says almost all electrical work needs a notification of work filed before it starts. Edmonton says all new electrical installations need a permit, including new circuits and wiring to a garden shed. Calgary requires one for new wiring or altered branch circuits. In British Columbia, Technical Safety BC requires a homeowner permit for many alterations, including hooking up fixed appliances.

Small-building exemptions do not cover the wiring. Lakewood, Colorado puts it plainly: a 200 square foot shed with power brought to it can fall under the building-permit exemption there, and it still needs an electrical permit.

Outdoor sauna: the building permit turns on size.

In the US, the model code exempts one-storey detached accessory structures up to 200 square feet from a building permit. Cities amend that number. Aurora, Texas and Turlock, California both set it at 120 sq ft. Turlock and Aurora also require a permit for any building with electrical or plumbing work, whatever its size.

In Canada, 10 square metres (107 sq ft) is the common line. Calgary and Oshawa both use it. Edmonton's exemption applies only to a building under 10 square metres that is not connected to electricity, plumbing or gas, so a wired sauna does not qualify.

A sauna is not always treated as a shed. Trent Lakes, Ontario advised in 2025 that a sauna over 10 square metres needs a building permit because it is not a storage building. In British Columbia, a local authority once ruled a small electric sauna a hazard because of its heat source and how long people stay inside. The provincial appeal board overturned that, and said hazard is judged case by case.

Setbacks and zoning apply whatever the size. A structure under the size threshold still has to sit the required distance from property lines and the house.

Sauna interior with a stone heater, timber benches and a window to the garden — The heater circuit is the part that needs a permit almost everywhere.

Indoor sauna: framing, plumbing and the circuit.

Building new walls or finishing an unfinished basement usually needs a building permit. Blaine, Minnesota is a typical example: finishing basement space needs one, and electrical work is a separate permit.

A shower beside the sauna adds plumbing work. Plumbing also ends the small-building exemption in places like Oshawa and Edmonton.

The heater circuit needs its electrical permit indoors exactly as it does outdoors.

Wood stoves and other gates.

A wood-burning sauna stove brings its own requirements. Lethbridge, Alberta requires a permit before a free-standing wood stove goes in, with the stove's certification, clearances to combustibles, the hearth pad and the chimney all on the application.

None of these replace each other. A building permit does not cover the wiring, and the wiring permit does not cover the building.

Who to call.

In the US: your city or county building department for the building and electrical permits, and the planning or zoning office for setbacks.

In Canada: your municipal building department for the building permit, zoning and setbacks. For the electrical work, Ontario's Electrical Safety Authority or a Licensed Electrical Contractor, Technical Safety BC in British Columbia, and in Alberta your city or county permit office.

Bring the sauna's size, where it will sit, the heater's kilowatt rating and the circuit it needs. Those are the details the permit office asks for.

Common questions.

Do I need a permit to build a sauna in my backyard?: Plan on an electrical permit for the heater circuit. Whether you also need a building permit depends on the sauna's floor area and your city's threshold, which is commonly between 10 square metres (107 sq ft) in Canada and 120 to 200 sq ft in US cities. Setbacks apply either way. Confirm with your local building department.
Do I need a permit for an indoor sauna?: The heater's 240 V circuit needs an electrical permit. Building new walls or finishing a basement for it usually needs a building permit too, and a shower beside it adds plumbing. Your local building department can tell you which apply to your project.
Does a small outdoor sauna count as a shed?: Not always. Trent Lakes, Ontario advised that a sauna over 10 square metres needs a building permit because it is not a storage building, and many shed exemptions apply only to buildings with no electrical connection. A wired sauna often falls outside them.
Who issues an electrical permit for a sauna?: In the US, your city or county building department. In Canada it depends on the province: the Electrical Safety Authority in Ontario, Technical Safety BC in British Columbia, and the city or county permit office in Alberta.

Sources.

For general information only, not medical advice. Ask a clinician before starting regular sauna use.

Keep reading.

Get the spec your permit office will ask for.

We send a drawing with the sauna's size, the heater's kilowatt rating and the circuit it needs, ready for your building department and electrician.

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Do I Need a Permit for a Sauna? US and Canada.