How do I convert a Calgary freestanding wood stove location into a built-in gas fireplace?

Converting a freestanding wood stove to a built-in gas fireplace is one of the more involved fireplace projects a Calgary homeowner can undertake — it touches gas fitting, framing, venting, finishing, and permits all at once. Done right, you end up with a clean, efficient heating appliance that's far more convenient than wood and perfectly suited to Calgary's long heating season.

Here's how the project unfolds from start to finish.

What You're Actually Replacing

A freestanding wood stove sits on a non-combustible hearth pad, connects to a Class A insulated chimney that exits through the ceiling or wall, and maintains large clearances to combustibles on all sides. A built-in direct-vent gas fireplace, by contrast, is framed into a wall cavity, vents horizontally through an exterior wall (or vertically), and requires a gas line connection. These are fundamentally different systems — almost nothing carries over except possibly the hearth pad, and even that depends on the new unit's footprint and clearance requirements.

The Removal Phase

The wood stove and its chimney system come out first. The Class A chimney pipe, roof or wall penetration, and any thimble assembly all need to be removed and the penetration properly patched and sealed — this is not cosmetic work, it's a building envelope repair that needs to be weathertight and insulated correctly for Calgary's climate. The hearth pad may stay if it's the right size and material for the new installation, or it gets removed if the new fireplace design calls for a flush floor finish.

Framing and Venting the New Unit

The new built-in gas fireplace needs a framed chase or alcove built to the manufacturer's specifications — exact dimensions matter because clearances to combustibles are governed by the Alberta Building Code and the unit's installation manual. Most direct-vent gas fireplaces in the 30,000-40,000 BTU range that Calgary homes need for serious supplemental heat require a framed opening roughly 36-48 inches wide and 36-48 inches tall, with specific side and top clearances.

Direct-vent is the right choice for this application. The coaxial vent pipe (air-in/exhaust-out in a single pipe) runs horizontally through the exterior wall — typically a short, clean run that's far simpler than the old chimney system. The termination cap location on the exterior wall must meet Alberta Building Code clearances from windows, doors, gas meters, and electrical outlets.

Gas Line and Permits — Non-Negotiable

A licensed gas fitter must run a new gas line to the fireplace location and connect the appliance. This is not optional and not DIY territory under any circumstances. The gas fitter pulls the gas permit from the City of Calgary (or your municipality if you're in Airdrie, Cochrane, Okotoks, or Chestermere), does the work, and a Safety Codes Officer inspects the completed installation before you fire it up. Permit fees run $100-$200. Skipping this step creates a serious safety hazard, voids your homeowner's insurance, and will surface as a liability on any future home inspection.

Finishing — Where the Project Becomes Visible

Once the fireplace is installed and inspected, the framing gets drywalled, and the surround and mantel go in. This is where Calgary homeowners typically invest in natural stone — ledgestone, stacked slate, or marble tile surrounds are popular and hold up beautifully through the thermal cycling of a Calgary heating season. A wood mantel shelf above adds warmth to the design but must maintain the minimum clearances from the firebox opening specified in the Alberta Building Code. Budget $1,500-$4,000 for a quality stone surround and mantel.

What This Project Costs in Calgary

A complete conversion — stove removal, chimney decommissioning, framing, direct-vent gas fireplace (Napoleon, Regency, or Valor in the 30,000-40,000 BTU range), gas line, permit, inspection, drywall, and a stone surround — typically runs $6,000-$12,000 in the Calgary market. Premium linear units with floor-to-ceiling stone can push $14,000-$15,000. Get at least two quotes and confirm each contractor includes the gas permit and Safety Codes Officer inspection in their scope.

Need help finding a fireplace installer for this project? Calgary Fireplaces can match you with local contractors for free — browse the Calgary Construction Network directory at calgaryconstructionnetwork.com/directory?trade=fireplaces.