Photo galleries are full of decks built for California. An Ontario deck has to handle frost that lifts footings, snow that sits on it for four months, and a season that is best in May, June and September, not only in July. This guide walks through the deck ideas we build most across Hamilton, Burlington and Oakville, what each one costs, and what it sets off in terms of permits, railings and structure, so you can pick a design that you can actually afford to build.
Deck ideas and what each one triggers
Most deck budgets go wrong because an idea brings a hidden requirement with it. This table shows the common ones before you fall in love with a photo.
| Deck idea | What it adds to the build | Cost effect |
|---|---|---|
| Low deck, under 600 mm | No guard required by code, often no permit if free-standing | Lowest cost per sqft |
| Raised deck off a walkout or door | Permit, guards, stairs, deeper footings and bigger beams | Adds 20 - 30 percent |
| Multi-level deck | Extra stairs, more footings, often guards on the upper level | Stairs $600 - $2,200 per run |
| Pergola on the deck | Posts tied into the frame or their own footings | $4,500 - $14,000 plus $800 - $2,500 for blocking |
| Roof over the deck | Permit, snow load design, footings sized for the roof | Priced as a small addition |
| Hot tub on the deck | Framing and footings designed for the weight, electrical | Usually engineered |
| Privacy wall | Posts tied into the frame, setbacks from lot lines | $90 - $220 per linear foot |
| Composite boards on a diagonal | Closer joist spacing | More framing lumber and labour |
For the full price breakdown by material and size, see our deck cost guide for Ontario or run your numbers through the deck cost calculator.
Backyard deck ideas that suit Ontario
1. The low platform deck
A deck that sits less than 600 mm (about 24 inches) above the ground does not need a guard under the Ontario Building Code, which removes the railing from the budget and the view. Free-standing low decks that are not attached to the house often need no permit, though you should confirm with your city before you build. It is the simplest way to turn a flat backyard into an outdoor room, and it pairs well with a patio or lawn on the same level. The catch is ventilation: a deck that sits close to the soil needs airflow and a gravel base under it, or the framing rots early.
2. The multi-level deck on a sloped yard
Many lots in Hamilton's mountain neighbourhoods, in Dundas and along the escarpment in Burlington slope away from the house. Instead of one tall deck on long posts, split it into two or three levels that step down with the grade. Each level stays lower, so less of the deck needs a guard, and each level becomes a zone: a dining platform by the kitchen door, a lounge level two or three steps down. The cost is in the stairs and the extra footings, and every stair has to meet the same rise and run rules as a stair to the yard. Our deck stairs code guide covers the numbers.
3. Zones instead of one big square
A 12 x 16 ft deck is 192 sqft, which sounds big until a dining table for six and a barbecue are on it. Plan the zones first: a dining table for six needs a space about 12 x 12 ft to pull chairs out, a lounge set about 10 x 12 ft, and a barbecue needs a clear corner away from the siding and the door. An L-shaped or wrap-around deck often gives you two usable rooms for less than one oversized rectangle.
4. A covered deck for spring and fall
In Ontario, the best deck weather is often in May and September, when evenings are cool and rain comes through fast. A roof over part of the deck lets you use it through those seasons. A solid roof is a structure that has to carry snow, so it needs a permit, footings sized for the load and a proper connection to the house. A pergola is the lighter option: it gives shade and a frame for lights and curtains, and a louvered aluminum pergola closes against rain. A 10 x 10 ft pergola is 9.3 m2, just under the 10 m2 permit threshold that applies in parts of our area, but a pergola bolted to a raised deck still has to be tied into a frame that can take it.
5. The hot tub deck
A filled hot tub with people in it weighs several times what a normal deck is framed to carry. There are two good ways to do it. Set the tub on its own concrete pad and build the deck around it, so the deck surface is flush with the tub rim. Or frame the deck for the load, with the beams, joists and footings designed for it, which usually means engineered drawings. The first is often cheaper and easier to get through a permit. Building beside an above-ground pool instead? See our above-ground pool deck ideas, because that deck becomes part of the pool enclosure. Plan the electrical early, since the disconnect has to be within sight of the tub, and use an ESA licensed electrician.
6. A privacy screen on one side
Most decks only need privacy from one direction. A single screen on the neighbour's side does more than boxing the whole deck in, and it has to follow the setback rules for your city. See our deck privacy wall ideas for the heights and setbacks in Hamilton and Oakville.
7. Wide stairs that double as seating
On a deck that is two or three steps above the yard, stairs that run most of the width of the deck become extra seating and make the deck and yard feel like one space. Keep the risers uniform, and remember that stairs with more than three risers need a handrail.
8. Built-in lighting
Post cap lights, riser lights on the stairs and a few lights in nearby beds make the deck usable after dark and safer on the steps. Low-voltage lighting is easiest to run while the deck is being framed. A small system of 6 to 8 fixtures runs about $2,400 to $4,800 installed; see our landscape lighting cost guide.
9. Simple and inexpensive
If the budget is tight, the cheapest good deck is a rectangle, in pressure-treated wood, low enough to skip the railing, with standard board lengths so there is little waste. Upgrade the parts you touch and see (the boards and the stairs) and keep the frame simple. You can add a pergola or lighting later if the frame is planned for it.
Materials for each idea
- Pressure-treated wood ($30 - $55 per sqft) suits low decks, budget builds and frames under every deck.
- Cedar ($45 - $75) looks better and resists rot naturally, but needs staining every two to three years. See how to stain a deck.
- Composite ($60 - $110) suits decks you want to hose off and forget. Most composite boards need joists at 16 inches on centre, and closer, often 12 inches, for diagonal or herringbone patterns, so check the manufacturer's span table before you pick a pattern.
- Aluminum or glass railings keep the view on raised decks. Horizontal and cable railings are still not allowed on required guards for a house under the Ontario Building Code, because a child can climb them. Our deck railing ideas and cost guide compares every style.
Our pressure-treated vs cedar vs composite comparison goes deeper on lifespan and upkeep.
What every Ontario deck needs underneath
- Footings below frost. Footings for a deck attached to the house go down about 1.2 m (4 ft) so frost does not lift them. A deck on surface blocks moves with the frost, which is fine for a free-standing low deck and a problem for an attached one.
- A proper ledger or a free-standing frame. A ledger bolted to the house needs flashing and the right fasteners. Many builders now make raised decks free-standing, with their own beam near the house, to avoid the ledger altogether.
- Guards where the drop is more than 600 mm. 900 mm high where the deck is up to 1,800 mm above grade, and 1,070 mm above that, with no opening that passes a 100 mm sphere.
- A permit when the deck is more than 600 mm high or attached. Your city will ask for a site plan and drawings. See our Ontario landscape permits guide.
- Locates before digging. Book free locates through Ontario One Call before any footing hole goes in.
Deck or patio?
If the back door is at ground level and the yard is flat, a patio usually costs about the same as a composite deck and lasts longer. If the door is more than a couple of steps up or the yard slopes, a deck is often the cheaper way to get a level outdoor room. Our deck vs patio guide compares the two side by side.
Door at ground level? See patio ideas and sizes for the same space.
Frequently asked questions
How much does a new deck cost in Ontario?
About $30 to $55 per square foot in pressure-treated wood, $45 to $75 in cedar and $60 to $110 in composite, installed in 2026. A 12 x 16 ft deck is 192 sqft, so roughly $5,800 to $21,000 depending on material, height and railings.
Do I need a permit for a deck in Ontario?
In Hamilton, Burlington, Oakville and most Ontario municipalities, a deck more than 600 mm (24 inches) above grade or attached to the house needs a building permit. A low, free-standing deck often does not, but confirm with your city first.
What is the cheapest deck design?
A low rectangular deck in pressure-treated wood, under 600 mm high so no railing is required, built with standard board lengths to cut waste.
Can I put a hot tub on my deck?
Only if the deck is framed and footed for the weight, which usually means engineered drawings. Setting the tub on its own concrete pad and building the deck around it is often simpler and cheaper.
Can I use cable railing on a deck in Ontario?
Not on a required guard for a house. The Ontario Building Code still does not allow guards that a child can climb, and horizontal cables act like a ladder. They can be used where no guard is required.
How deep do deck footings need to be in Hamilton?
About 1.2 m (4 ft) for a deck attached to the house, so frost cannot lift them. Free-standing low decks can sit on surface footings because they are allowed to move.
What size deck do I need?
Plan about 12 x 12 ft for a dining table for six with room to pull out chairs, and about 10 x 12 ft for a lounge set. Add a clear area for the barbecue and the path to the door.
Is a covered deck worth it in Ontario?
For many families, yes, because it makes the deck usable in May, June and September rain. A solid roof needs a permit and snow-load design, so it costs much more than a pergola.