The most common deck-design regret in Ontario isn’t the colour or the railing — it’s a deck that’s the wrong size, in the wrong spot, for the way the family actually lives. Below we answer the seven size, design, and resale questions homeowners ask most. This page is part of our complete guide to building a deck in Ontario.

How big should your deck be?

How big should my deck be (square feet per person)?

Plan roughly 30–50 sq ft per person you want to seat or stand comfortably. A small bistro deck is about 100–150 sq ft; a family deck with a dining table and a lounge area runs 300–400 sq ft. Map your furniture first — a dining set needs about 12 x 12 ft of clear space — then size the deck around it.

How big can I build relative to lot coverage?

Your deck usually counts toward your lot’s maximum lot coverage, so the ceiling is set by zoning, not just taste. Many Ontario residential lots allow roughly 30–45% coverage of all structures combined. Check your zoning by-law before you design — and remember setbacks from the property line also limit where the deck can sit.

Coverage and setbacks are two separate limits that both apply. Coverage caps the total footprint; setbacks keep the deck a set distance from each lot line. A big deck can pass one and fail the other, so confirm both early — the details are in our deck setbacks & zoning guide, and whether it all needs a permit is in the Ontario deck permit guide.

Does a deck add value? Resale and ROI

Does a deck add value, and what’s the ROI?

Yes — a well-built deck is one of the better-returning outdoor projects, commonly recouping around 60–75% of its cost at resale, plus real value as usable living space while you own the home. The return is best when the deck suits the house and yard; an oversized or awkward deck adds far less.

Think of the ROI in two parts: the resale bump when you sell, and the years of outdoor living you get in the meantime. Pressure-treated decks cost less up front but a low-maintenance composite deck can show better to buyers. Price your build realistically first with the cost to build a deck guide so the return math is honest.

What size gives the best resale return?

The best resale return comes from a deck proportional to the house and lot — usually a single, well-finished main deck rather than the biggest structure that fits. Buyers pay for a usable, low-maintenance outdoor room, not square footage for its own sake. Quality materials and clean design beat sheer size every time.

Designing a deck you’ll actually use

Multi-level vs single level — which?

Single-level is cheaper, simpler, and easier to furnish — the right call for most flat yards. Go multi-level when the grade drops, when you want to define zones (dining vs lounge vs hot tub), or to step down toward a pool. Each level adds framing, stairs, and cost, so only split it for a real reason.

Sun and shade orientation — how do I avoid an unusable deck?

Orientation makes or breaks a deck. A west-facing deck bakes in the late-afternoon sun exactly when you want to use it; a north-facing one can feel cold and shady. Note where the sun sits at 5–7 pm in summer, then plan shade — a pergola, awning, or tree — so the deck is comfortable when you’ll actually sit on it.

Should I plan now for a future hot tub, pergola or roof?

Yes — decide now, because hot tubs, pergolas, and roofs all change the structure. A hot tub needs far heavier framing and footings; a roof adds load and ledger work. It’s far cheaper to build the support in from the start than to tear into a finished deck later. Flag any future plans on your drawings.

Even if you won’t install it this year, designing the framing for it now is cheap insurance. A hot tub in particular can more than double the load on that part of the deck — see exactly what it takes in our hot tub & pool deck guide before you finalize the layout.

Frequently asked questions