Planning a deck in Ontario? A building permit is required if your deck is attached to the house, exceeds 600mm height, or is over 10 sq metres. Frost-depth footings (1.2m in the GTA) are mandatory.
Material cost ranges (installed, 2026):
- Pressure-treated lumber: $25-$40/sq ft
- Composite (Trex/TimberTech): $55-$90/sq ft
- Hardwood (ipe/cumaru): $80-$130/sq ft
Guardrails are required above 600mm – minimum 900mm height, 100mm baluster spacing. Corner lot setbacks and lot coverage limits apply in addition to OBC.
Contractor checklist: WSIB coverage, $2M liability, permit pull included in contract, 10% lien holdback to Certificate of Completion.
Permit fees run $200-$600 in most GTA municipalities. Structural engineer letters for complex designs add $500-$1,200.
Anyone here recently gone through the permit process in Toronto or Mississauga? How long did approval take?
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