What a Composite Deck Actually Costs in the GTA (2026)
Composite decking has gone from alternative to default for GTA homeowners who are done with staining wood every second summer. But composite quotes vary enormously, and the per-square-foot numbers thrown around online rarely survive contact with a real backyard. Here is what composite deck projects actually cost across Oakville, Mississauga, Burlington, and the GTA in 2026, and what moves the number.
These are market ranges to budget against, not a quote. Deck pricing is driven by height, structure, and railing choices as much as by the boards themselves, which is why two decks of identical size can be thousands apart, and both quotes can be fair.
The 2026 Numbers
Most professionally built composite decks in the GTA land between $55 and $110 per square foot in 2026, complete: footings, pressure-treated substructure, composite decking, and railings. A typical 300 square foot ground-oriented deck lands in the $18,000 to $28,000 range; a larger elevated deck with premium boards, glass or aluminum railings, and stairs can pass $40,000.
For comparison, a pressure-treated wood deck typically runs $35 to $60 per square foot built. Composite costs roughly 40 to 60 percent more up front, and the payback argument comes later.
What Drives the Price
Height and structure come first. A ground-hugging deck needs modest framing; a walkout deck eight feet up needs engineered posts, beams, deeper footings, and stairs, and the structure can cost more than the decking. Railings are the quiet budget killer: basic composite or aluminum railing is affordable, while glass panels can add tens of dollars per linear foot and transform the quote. Board tier matters too, as entry composite and premium mineral-based boards can differ by 50 percent or more. Finally, complexity: wraparounds, multiple levels, built-in benches, privacy screens, and pergolas all add carpentry hours.
Do You Need a Permit?
In most GTA municipalities, including Oakville, Milton, and Burlington, a deck needs a building permit once it is attached to the house or above a threshold height, commonly 24 inches. Permits add drawings, fees, and a few weeks of lead time, and skipping one creates real problems at resale or insurance time. This is routine for us: our drawings and permits service handles it as part of the project.
The Maintenance Math
A wood deck demands washing and re-staining every two to three years. Price that honestly, a few hundred dollars in materials each round or four figures hired out, over 15 years, and the composite premium shrinks dramatically. Composite needs soap and water. Add that quality composite carries 25 to 50 year fade-and-stain warranties versus wood's 10 to 15 year realistic lifespan in Ontario's freeze-thaw climate, and composite is usually the cheaper deck over its life, despite the bigger first cheque. Choosing between wood, composite, and PVC deserves its own decision, and our decking material comparison covers it board by board.
Getting a Real Number
A proper deck quote follows a site visit: checking grade, house attachment, soil for footings, and municipal requirements, then pricing your actual design in two or three board tiers so you can see the trade-offs. That is how our deck builds and custom carpentry work at Conscape, from Milton across the GTA. Planning a deck for this season or next spring's queue? Request a quote and we will price it properly.