What are the best heating options for a detached garage in Ottawa that gets used year-round?

Heating a detached garage in Ottawa to usable levels through our winters is absolutely achievable, but the approach you choose needs to match the space, your budget, and how often you will be out there. The most common and practical options for Ottawa homeowners are natural gas unit heaters, electric infrared heaters, and ductless mini-split heat pumps, each with distinct advantages.

A natural gas unit heater (like a Modine or Reznor) is the most popular choice for Ottawa detached garages and for good reason. These units hang from the ceiling, take up no floor space, and produce serious heat — a 45,000 BTU unit can warm a two-car garage from -20°C to +15°C in under 30 minutes. Installation costs run $2,500 to $4,500 including the gas line extension from your house, venting, and the unit itself. Operating costs are reasonable because natural gas remains cheaper than electricity for high-demand heating in Ontario. The main requirement is that you need a gas line run to the garage, which means trenching from your house and getting a gas permit. Your garage also needs proper combustion air ventilation per Ontario Building Code — the installer will size the intake vent based on the heater's BTU rating.

Electric infrared (radiant) heaters are a good option when running a gas line is impractical or too expensive. Ceiling-mounted infrared panels heat objects and surfaces directly rather than warming the air, which means you feel the warmth quickly even in a cold space. A two-car garage typically needs 4,000 to 6,000 watts of infrared capacity, and the units cost $800 to $2,000 installed. The downside is operating cost — at Ontario electricity rates, running electric heat in a large garage through an Ottawa winter gets expensive, typically $150 to $300 per month if you heat regularly. These work best for garages used intermittently rather than continuously.

A ductless mini-split heat pump is the most energy-efficient option and the only one that provides both heating and cooling. Modern cold-climate mini-splits (like Mitsubishi Hyper-Heat or Fujitsu XLTH) can extract heat from outdoor air down to -25°C to -30°C, which covers most of Ottawa's winter. A single-zone system for a two-car garage costs $4,000 to $7,000 installed. The efficiency advantage is significant — a heat pump delivers 2 to 3 times more heat energy per dollar than direct electric resistance heating. The limitation is that output drops as temperatures fall, so during Ottawa's coldest stretches you may want a supplemental heat source.

In-floor radiant heating (hydronic, embedded in the concrete slab) is the premium option that provides the most comfortable and even heat. It must be planned during construction since the tubing is cast into the slab. Cost for a two-car garage is $6,000 to $12,000 including the boiler or heat source. The heat rises gently from the floor, keeping vehicles and workbenches warm and melting snow off parked cars naturally. It is the most expensive option but also the most pleasant to use.

Regardless of which heating system you choose, insulation is a prerequisite. Heating an uninsulated Ottawa garage is like running your furnace with the windows open. All electrical heating installations require work by an ESA-registered electrician.

Explore heating-ready garage designs through Ottawa Garages, where you can find builders who integrate heating planning into the construction process from day one.

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