Do I need to upgrade my furnace and air conditioning for a second storey in Ottawa?

Usually, yes, at least in part. Your existing furnace, air conditioner and ductwork were designed for a one-storey layout, and adding a second storey adds a lot of space to heat and cool. Leaving the system as it is tends to lead to uneven temperatures, higher bills and equipment that works harder than it should.

Start with sizing. The right way to decide what equipment you need is a heat-loss and heat-gain calculation for the whole house as it will be after the addition, done by your HVAC contractor or designer. Rules of thumb based on square footage aren't reliable, because insulation, windows, air sealing and orientation all change the answer. With winters that regularly reach well below -20°C, getting heating capacity right matters for comfort and to protect your plumbing.

Cooling follows the same logic. Upper floors are harder to cool because heat rises, and humid summers add load. Depending on the calculation, you may need a larger air conditioner or could consider a cold-climate heat pump that handles both heating and cooling. Ask contractors to quote the options that the calculation supports, itemized, so you can compare them.

Ductwork is often the hardest part. The existing ducts run through the basement and main floor, and they have to reach the new storey. In many bungalows there's no easy path, so options include running ducts through interior walls, building bulkheads on the main floor, or using separate runs for each floor. Ask how each contractor plans to route ducts and where returns will go, since poor returns are a common cause of a hot upper floor.

Zoning, with dampers and a thermostat for each floor, helps balance a two-storey house so you aren't fighting a hot upstairs and cool main floor. Ask whether it suits your layout.

On the regulatory side, gas work is done by a TSSA-certified gas technician, and electrical connections for new equipment need an ESA notification or permit handled by an electrical contractor licensed by ESA. The addition's building permit covers the mechanical design, and the City inspects rough-ins before walls are closed.

Total HVAC cost depends on the equipment, the duct routing and whether you add zoning, so ask for an itemized mechanical line in every quote. You can browse addition contractors in the Ottawa Construction Network directory and compare those quotes.

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

• Homeupgraders
• RenoMotion Inc.
• The Granite shop
• Steven Labelle - Your Complete Home Renovator
• Best Hand2Hand moving company