What does a complete ductwork replacement cost in a two-storey Toronto home?

A complete ductwork replacement in a two-storey Toronto home typically costs $8,000 to $18,000, with the average GTA homeowner paying $10,000 to $14,000 for a properly designed and installed galvanized steel system. The wide range reflects differences in home size, layout complexity, accessibility, and whether asbestos abatement is needed on the existing ductwork.

The cost breaks down into several components. Demolition and removal of the old duct system runs $1,000 to $3,000 depending on the size and complexity. If your home was built before 1980, the existing ductwork may have asbestos tape or insulation at joints — particularly common in post-war homes across Scarborough, North York, Etobicoke, and the inner suburbs. Professional asbestos testing costs $200 to $400, and if asbestos is confirmed, abatement adds $2,000 to $5,000 to the project. Never attempt to remove asbestos-wrapped ductwork yourself — Ontario regulations require licensed abatement contractors.

The new duct system itself — design, materials, and installation — accounts for the bulk of the cost at $6,000 to $15,000. A proper replacement starts with Manual J load calculations and Manual D duct sizing, ensuring every room gets the right amount of conditioned air. The trunk line, typically rectangular galvanized steel at $12 to $30 per linear foot installed, runs through the basement ceiling. Branch supply ducts in round galvanized or spiral duct at $8 to $20 per linear foot run from the trunk to individual rooms. A two-storey home needs supply and return ducts reaching both floors, which usually means running ducts through interior wall cavities, floor joist bays, or dedicated chases.

The second-floor ductwork is where costs escalate in two-storey homes. Getting ducts from the basement to the second floor requires vertical chases through closets, walls, or purpose-built soffits. In older Toronto homes that were not originally designed with duct chases, creative routing is necessary, and this takes time and skill. Some contractors recommend high-velocity small-duct systems like SpacePak or Unico for second-floor retrofits — these use 2-inch flexible tubing that threads through existing wall cavities without major demolition, but the systems cost $10,000 to $20,000 installed.

Return air is critically important and often inadequate in older GTA homes. Many post-war Toronto homes have a single return grille on the main floor, which is grossly insufficient for a two-storey layout. A proper replacement adds dedicated return air ducts to every bedroom and the second-floor hallway, which dramatically improves comfort, reduces noise, and allows doors to be closed without creating pressure imbalances. Budget $300 to $800 per return register added.

City of Toronto mechanical permits for a complete duct replacement typically cost $200 to $800. The project usually takes two to four days for a professional crew. Browse HVAC and ductwork contractors in the Toronto Construction Network directory to get competitive quotes from experienced local professionals.