Can I install two gas fireplaces on one gas line in my Calgary two-storey home?

Yes, you can typically install two gas fireplaces on one gas line in your Calgary home, but the gas line must be properly sized to supply adequate gas flow to both units simultaneously. This is a common setup in two-storey Calgary homes where homeowners want a main floor living room fireplace and an upstairs master bedroom or family room fireplace.

The key factor is gas line sizing and pressure. Each gas fireplace requires a specific gas flow rate measured in cubic feet per hour (CFH) — typically 25-60 CFH depending on the fireplace's BTU rating. A 30,000 BTU gas fireplace needs approximately 30 CFH, while a 40,000 BTU unit requires about 40 CFH. When both fireplaces operate simultaneously, the gas line must deliver the combined flow rate without pressure drop that would cause poor flame performance or safety issues.

ATCO Gas delivers natural gas to Calgary homes at approximately 7 inches of water column pressure, which is adequate for multiple appliances when the distribution system is properly designed. Your home's existing gas line from the meter may need upgrading from 3/4-inch to 1-inch diameter pipe, or the branch lines to each fireplace may need to be 3/4-inch instead of 1/2-inch. A licensed gas fitter will calculate the total gas load including your furnace, water heater, and both fireplaces to determine the correct pipe sizing.

Each fireplace requires its own gas permit from the City of Calgary, even when connected to a shared gas line. The gas fitter will pull permits for both units and the Safety Codes Officer will inspect each fireplace installation separately. This ensures proper gas connections, adequate venting, and compliance with Alberta Building Code clearance requirements for both units. Permit fees typically run $100-$200 per fireplace.

Venting is completely independent between the two fireplaces. Each direct-vent gas fireplace has its own sealed combustion system and dedicated vent pipe to the exterior. The upstairs fireplace can vent horizontally through an exterior wall or vertically through the roof, while the main floor unit typically vents horizontally. Proper vent termination clearances must be maintained — 3 feet from windows, doors, or air intakes, and adequate separation between the two vent terminals.

Installation costs for dual fireplaces typically range $6,000-$12,000 total, depending on the fireplace models, gas line modifications required, and finishing work. Installing both units simultaneously is more cost-effective than separate projects because the gas fitter can run both lines during one visit and coordinate permits together.

Consider the heating load carefully — two gas fireplaces can provide 50,000-80,000 BTU of supplemental heat, which is substantial zone heating during Calgary's brutal winter months when temperatures drop to -30°C. This reduces strain on your furnace and creates comfortable heating zones in the rooms you use most during the long heating season from October through April.

Need help finding a licensed gas fitter for your dual fireplace project? Calgary Fireplaces can match you with local fireplace contractors who handle multi-unit installations and gas line sizing through the Calgary Construction Network.