Home additions are the most complex and highest-value residential projects. This thread covers second storey additions, rear extensions, and garden suites in Ontario for 2026.
Second Storey Additions
Adding a full second storey to a bungalow: $200,000-$400,000+ in the GTA. Foundation and main floor structure must be assessed for load capacity before any design work. Expect 12-18 months for permit approval in Toronto for a full second-storey addition. Temporary relocation during construction ($3,000-$8,000/month) must be factored into the budget.
Rear Additions
Single-storey rear addition (200-400 sq ft): $90,000-$180,000 in the GTA. Zoning setback requirements limit rear additions - typically 7.5m from rear lot line in Toronto residential zones. A new survey and site plan are required for permit applications in most GTA municipalities.
Garden Suites and Laneway Homes
Toronto legalized garden suites in 2022. Build costs: $180,000-$350,000 for a self-contained unit with kitchen and bath. Rental income potential of $2,200-$3,500/month. Lot eligibility depends on lane access, setbacks, and lot coverage limits. Many GTA homeowners are adding garden suites as mortgage helpers.
Permit and Design Resources
LF Builders handles addition projects from design through permits to completion: https://lfbuilders.ca
Discuss your addition project - budget, permits, contractor selection - at https://home.renovation.reviews