What does a two-sided see-through fireplace installation cost in Ottawa including structural work?

A two-sided see-through fireplace (also called a double-sided or see-through fireplace) typically costs $5,500 to $14,000 installed in Ottawa, depending on the appliance type, whether structural modifications are required, and the complexity of venting and framing work. Gas models dominate this category, with a quality direct-vent linear unit running $5,000 to $12,000 for the appliance alone, plus $1,500 to $3,000 for installation labour and venting — total of $6,500 to $15,000. Wood-burning see-through inserts and stoves are less common but possible, running $4,000 to $8,000 for the unit plus $2,000 to $4,000 for chimney work and installation.

Why this matters in Ottawa specifically: A two-sided fireplace is architecturally ambitious and comes with unique structural demands in Ottawa's climate. These units typically sit in an opening that penetrates from one room into another, which means you're essentially creating a new flue opening in your home's thermal envelope. Ottawa's extreme temperature swings put enormous stress on new structural penetrations — poor installation can lead to air leakage, heat loss, condensation problems, and accelerated deterioration of framing and masonry around the opening. The structural work to accommodate a see-through fireplace is where costs can escalate dramatically, and this is where most problems arise if corners are cut.

The structural work required depends on where you want the fireplace to sit. If you're installing it in an existing masonry chimney or fireplace opening that already penetrates the roof, costs stay on the lower end — you're essentially replacing or upgrading an existing system, which might run $4,000 to $7,000 total. If you're creating a new opening between two rooms (perhaps removing a section of wall or a chimney breast that currently exists), you need to build a proper structural frame, install a steel lintel or beam to support the load above, potentially reroute utilities, and create a new chimney or vent opening through the roofline — this structural work alone can cost $2,000 to $5,000 before the fireplace is even installed. If you're adding a see-through fireplace to a location where no chimney currently exists, you need to frame a new chase (the structure that houses the vent pipe and chimney), insulate it properly, run either a new gas line or chimney pipe through it, and exit through the roof — this can run $3,000 to $6,000 in structural and framing work alone.

The appliance itself and venting configuration add significant cost layers. A quality direct-vent linear gas fireplace (the most popular choice for two-sided installations because they draw combustion air from outside and vent through a sealed double-wall pipe) runs $4,500 to $10,000 for the unit. Premium brands and larger sizes push toward the higher end. The venting itself — which must be properly sized, supported, and sealed to prevent air leakage in Ottawa's climate — typically costs $800 to $1,500 in materials and labour. Gas line installation to reach the fireplace location can add another $500 to $1,500 if you don't already have a gas outlet nearby. TSSA compliance and the final gas tag from a licensed gas fitter are built into professional installation costs, usually around $300 to $500 of the total.

Labour costs for the actual fireplace installation — setting the unit, connecting gas, installing the vent, sealing clearances, and finishing the installation — typically run $1,500 to $2,500 for a straightforward setup. If structural framing, lintel installation, or significant cutting and modification of the home's exterior is required, installation labour can reach $3,000 to $4,000.

A realistic Ottawa pricing example: A homeowner wants to install a two-sided direct-vent linear gas fireplace between a living room and master bedroom, where no chimney currently exists. They need a new structural frame built around the opening, proper insulation and draftstopping, a gas line extended to the location, and a vent opening cut through the roofline. Breakdown: structural framing and lintel ($2,500), fireplace unit ($6,500), venting materials and installation ($1,200), gas line extension ($800), labour for assembly, connection, and finishing ($2,500), TSSA licensing and compliance ($400), chimney cap and flashing installation ($500). Total: approximately $14,900. This is not an exceptional cost in Ottawa for this type of work — it reflects the real complexity of creating a new thermal penetration in a climate where every breach in the building envelope has consequences.

A critical consideration unique to Ottawa: Two-sided fireplaces create exposed venting that exits through the roofline, and that means a new chimney flashing that must withstand Ottawa's brutal freeze-thaw cycling. Flashing failures are one of the most common water infiltration points in Ottawa homes, and they are especially problematic with newer penetrations that haven't had time to settle. The flashing must be installed by someone who understands ice dam formation, snow load behaviour, and the specific challenges of Ottawa Valley weather. A poorly installed flashing on a two-sided fireplace can result in water leaks into the attic or walls within the first winter — a costly mistake that should make you very cautious about who does the structural and roofline work.

Also note that two-sided fireplaces have specific clearance-to-combustible requirements on both sides of the unit. The Ontario Building Code specifies minimum distances from the fireplace to walls, furniture, and other combustible materials on each side. These clearances are NOT flexible, and if you're working in a tight space, you may discover during the design phase that a two-sided unit won't fit safely. A professional installer will lay out these clearances in advance so you know exactly what the footprint will be.

Building permits are typically required for structural modifications and new venting penetrations, and they add 4 to 8 weeks to your timeline if you haven't already factored that in. Plan ahead — the outdoor construction season in Ottawa (May through October, and really May through September for reliable weather) is short, and structural work combined with roofline venting penetrations should not be rushed in marginal weather conditions.

If you're seriously considering a two-sided fireplace, connecting with an experienced local fireplace contractor through the Ottawa Construction Network directory will help you understand the exact structural requirements for your specific space and get accurate quotes. This is complex work where poor planning or installation can have ripple effects throughout the home, so the expertise matters more than the cost.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• 613Bins
• The Egress Group Inc
• MAK Construction and Development Inc
• Beauty of gardens
• Vanguard Environmental