How much does it cost to convert from radiant heat to forced air with ductwork in Toronto?

Converting from radiant heat (hot water baseboards or in-floor radiant) to a forced-air system with full ductwork in a Toronto home typically costs $12,000 to $30,000, making it one of the most significant mechanical upgrades a GTA homeowner can undertake. The cost reflects the fact that you are essentially installing a complete HVAC system from scratch — there is no existing ductwork to build on.

The project involves several major components. A new furnace costs $3,000 to $6,000 installed, depending on efficiency rating, capacity, and brand. Most GTA homeowners choose a high-efficiency condensing furnace (96 to 98 percent AFUE) to minimize gas costs through Toronto's long heating season. If you want air conditioning — and most homeowners making this conversion do, since radiant systems cannot provide cooling — add $3,500 to $6,500 for a central air conditioner or heat pump, including the evaporator coil, refrigerant lines, and outdoor condenser unit. The ductwork itself, including design, materials, and installation, runs $5,000 to $15,000 depending on your home's size, layout, and how the ducts are routed.

The biggest challenge with this conversion in Toronto's existing housing stock is finding space for the ductwork. Radiant-heated homes were never designed with duct chases, soffits, or wall cavities sized for ductwork. In a bungalow or home with an unfinished basement, trunk lines can run along the basement ceiling with branches going up through floor cavities to first-floor registers — this is the simplest and least expensive scenario at $12,000 to $18,000 total. In a two-storey home, getting ducts to the second floor requires building chases through closets, creating soffits in hallways, or using a high-velocity small-duct system ($10,000 to $20,000 for the duct system alone) that threads 2-inch tubing through existing wall cavities.

GTA-specific factors affect this conversion significantly. Many mid-century Toronto homes in neighbourhoods like the Beaches, Leaside, and Lawrence Park have hot water radiant baseboards with a boiler. If the boiler also heats your domestic hot water, you will need a new water heater ($1,500 to $3,000 installed) unless you keep the boiler running for hot water only. Homes with in-floor radiant in the basement slab can keep that system operational for basement heating while adding forced air for the upper floors — a hybrid approach that many Toronto homeowners prefer.

This project requires a City of Toronto building permit covering the mechanical work, and the gas furnace installation must be performed by a TSSA-registered contractor. Budget $200 to $800 for permit fees. The entire conversion typically takes one to two weeks. A Manual J load calculation and Manual D duct design are essential — this is not a project where a contractor should be sizing ducts by feel. Get matched with experienced ductwork professionals through the Toronto Construction Network to compare quotes and approaches for your specific home.