How much does it cost to install a gas fireplace in a basement apartment in Ottawa with separate venting?

Installing a gas fireplace in a basement apartment in Ottawa with dedicated venting typically runs $4,500 to $8,500 installed, depending on the unit you choose, how far the vent needs to run, and the complexity of routing it through the foundation or rim joist. That range assumes a direct-vent gas fireplace, which is the only appropriate choice for a basement apartment setting.

Why Direct-Vent Is the Only Realistic Option Here

A basement apartment presents specific challenges that make the venting question more consequential than it would be for a main-floor installation. Direct-vent gas fireplaces draw combustion air from outside through a sealed, co-axial pipe system and exhaust through the same pipe — meaning the appliance is completely isolated from the room's air supply. This matters enormously in a basement, where natural air circulation is limited, negative pressure can build up quickly, and carbon monoxide has nowhere to go if combustion gases were ever to backdraft into the space. B-vent systems, which draw combustion air from inside the room, are poorly suited to basement apartments for exactly this reason. Ventless gas fireplaces are restricted under the Ontario Building Code for indoor use and should never be considered.

For a basement installation, the vent pipe typically exits horizontally through the rim joist or foundation wall, terminating on the exterior of the building. This is usually the most straightforward venting path and keeps the run short — typically 1 to 4 metres — which helps maintain good draft and keeps installation costs reasonable. Longer horizontal runs or configurations that require vertical termination above grade add cost. The vent termination must be positioned carefully to avoid being blocked by snow accumulation in winter, which is a genuine concern in Ottawa given the city's average of over 200 centimetres of snow annually. A termination that gets buried in a snowbank creates a dangerous backdraft situation.

On the cost breakdown, expect to pay $2,500 to $5,500 for the direct-vent unit itself depending on size and features, $500 to $1,500 for a new gas line run to the fireplace location if one doesn't already exist, $300 to $800 for the venting materials and termination, and $500 to $1,000 for labour depending on the complexity of the installation. If the apartment is in a secondary suite and the gas meter serves the whole house, you'll also need to discuss with your gas fitter how the new appliance will be metered or billed — this is worth sorting out before installation begins.

All gas fireplace work in Ontario must be performed by a TSSA-licensed gas fitter — this is a legal requirement, not a suggestion. The gas fitter will tag the appliance with a compliance label upon completion. If this is a rental unit, your landlord's insurance will almost certainly require documentation of licensed installation, and tenants should confirm the work is properly permitted and inspected before occupying the space with the appliance in use. A building permit from the City of Ottawa is also required for this type of installation.

If you're ready to get quotes, you can browse gas fireplace contractors through the Ottawa Construction Network directory at justynrookcontracting.com/directory — getting at least three written quotes that specify the unit, venting configuration, gas line work, permit responsibilities, and warranty terms will give you a solid basis for comparison.