What are the best ductwork layout options for an open-concept Toronto home renovation?

The best ductwork layout for an open-concept Toronto renovation depends on whether you're working with a basement mechanical room, where the trunk lines can run, and how you plan to handle the loss of interior walls that previously concealed return air pathways. Removing walls to create open-concept living spaces is one of the most popular renovation projects in the GTA, but it creates real challenges for ductwork that many homeowners don't anticipate until walls are already down.

When interior walls are removed, the supply and return duct runs inside those walls are eliminated. In many older Toronto homes — particularly the 1950s to 1980s housing stock across the inner suburbs — supply ducts run up through wall cavities from the basement to feed second-floor registers, and return air travels through stud cavities or panned joist spaces back to the furnace. Knocking out a wall without a plan for rerouting these ducts leaves rooms without supply air, return air, or both. The most effective approach is to plan the ductwork layout before demolition begins, not after.

For a basement-run system — the most common layout in GTA homes — the primary strategy is to keep the main trunk line in the basement ceiling and run supply branches up to the main floor through remaining walls, soffits, or the floor itself. Floor registers work well in open-concept layouts because they don't require wall cavities. Recessing ducts into the basement ceiling joists and using low-profile floor register boots allows supply air to reach any part of the open space without visible ductwork on the main floor. This approach typically costs $300 to $800 per relocated supply run.

Soffits and bulkheads are the practical solution when ductwork must cross an open-concept ceiling. A well-designed soffit running along the perimeter of the room — typically 10 to 14 inches deep and 12 to 16 inches wide — can conceal a supply trunk and multiple branch runs while looking intentional as an architectural detail. Many GTA designers integrate LED lighting or crown moulding into soffits to make them feel like a design feature rather than a mechanical necessity. Building a soffit to conceal ductwork typically costs $40 to $80 per linear foot for framing and drywall, plus the duct relocation costs.

Return air is the bigger challenge in open-concept layouts. With fewer walls available for return grilles and duct runs, you need a strategy to get air back to the furnace. Options include centralized high-wall return grilles in remaining hallway walls, floor-mounted returns with ducts running through basement joist cavities (properly ducted, not panned joist), or a dedicated return duct chase built into a closet or utility area. In open-concept spaces, undersized return air causes the furnace blower to work harder, increases noise, and pulls unconditioned air through the building envelope.

Exposed ductwork is increasingly popular in GTA loft-style renovations and industrial-aesthetic basements. Spiral round duct at $10 to $25 per linear foot installed provides a clean, modern look when painted to match or contrast with the ceiling. This approach eliminates the cost of concealment but requires careful layout planning to keep the runs neat and organized.

A qualified HVAC contractor should be involved in the renovation planning from the beginning — not brought in after the framing is done. Manual D duct design for an open-concept layout ensures the system delivers balanced comfort throughout the space. Find local ductwork professionals through the Toronto Construction Network at torontoconstructionnetwork.com.