Pool Fence Rules in the GTA and Durham, by City

Ontario has no province-wide rule for backyard pool fences. The Ontario Building Code only covers public pools, so every requirement for a home pool comes from the municipal bylaw, and the numbers genuinely differ from one city to the next.

That matters more than it sounds. A crew that carries one spec across the Durham line builds a fence that fails inspection.

Heights shown are for a single residential property. Multi-unit and commercial properties are higher in most cities. Fees change, so treat them as an order of magnitude and confirm before you budget.

The 1.2 m versus 1.5 m split

This is the single most expensive thing to get wrong. Most of the GTA sets the minimum at 1.2 m or 1.22 m. Ajax, Oshawa and Aurora require 1.5 m.

Ajax is the one that catches people, because both of its Durham neighbours, Pickering and Whitby, are 1.2 m. A fence built to the Pickering standard a few streets away in Ajax is 30 centimetres short, and short means taking panels down and starting again.

Gate hardware

Every municipality we checked requires the same two things: the gate must be self-closing, and it must have a self-latching device. Where they differ is the latch position.

• Most cities want the latch on the inside face, at or near the top of the gate.
• Toronto, Vaughan, Richmond Hill and Aurora allow an outside latch instead, if it sits at least 1.5 m above grade.
• Oakville sets its own figure at 1.22 m, and Whitby at 1.2 m.
• Markham and Oshawa also require a cover plate of at least 300 mm by 300 mm over the latch on metal gates.
• Ajax and Aurora ban quick-release hardware that lets the gate be opened from outside.

You will see it written online that pool gates have to swing outward, away from the pool. We could not find that requirement in any of the sixteen bylaws. None of them specify a swing direction. If a supplier tells you otherwise, ask them which section says so.

Gaps, openings and climbing

Three rules do most of the work, and they exist because a child who can get a toe in can get over.

• Gap underneath. Usually 100 mm. Oakville is the strictest at 50 mm, and Richmond Hill requires the facing to start within 50 mm of grade.
• Openings between members. 38 mm where horizontal rails sit less than 1.2 m apart, opening up to 100 mm where the rails are at least 1.2 m apart. Oakville defaults to a 38 mm sphere test throughout.
• Nothing climbable on the outside. Almost every bylaw bans horizontal or diagonal bracing on the outside face between roughly 100 mm and 1.2 m above grade. Several also require the fence to sit at least 1 m clear of anything else climbable, like an AC unit, a planter or a retaining wall.

That last one is why a horizontal board fence is a poor choice for a pool enclosure unless it is built with the rails inside. It is also why the shed you are planning to put beside the fence matters.

The fence goes up before the water

Every municipality we checked prohibits filling a pool before the enclosure is in place. Most require an inspection first, not just a finished fence.

Several go further. Vaughan requires temporary fencing before excavation starts. Toronto, Markham, Richmond Hill, Oakville and Stouffville all require temporary fencing through construction. Aurora is the only one of the sixteen that lets you fill the pool once a temporary enclosure is up, and even then the pool cannot be used until the permanent fence passes.

If your pool builder has given you a fill date, the fence has to be finished and inspected before it, not after.

Hot tubs are not treated the same everywhere

Most cities let a locked hard cover take the place of a fence. Three do not.

• Vaughan has no hot tub provision and no cover exemption. A hot tub deeper than 76 cm needs a full compliant enclosure.
• Ajax includes hot tubs and spas in its pool definition with no cover exemption in the bylaw text.
• Newmarket requires an enclosure permit for a hot tub even with a lockable lid.

Where a cover does exempt you, the cover has to earn it. Most cities require one that supports 90.72 kg, which is 200 lb, permanently attached and locked when not in use. Aurora is the outlier at 27.2 kg, about 60 lb.

What we build to

When a job crosses municipal lines, or when the bylaw is ambiguous, we build to a spec that clears all of them:

• 1.22 m minimum height, 1.5 m in Ajax, Oshawa and Aurora
• No gap over 50 mm under the fence
• No opening that passes a 38 mm sphere
• Nothing horizontal or diagonal on the outside face below 1.2 m
• Self-closing gate with a lockable self-latching device, latch inside at the top
• Enclosure complete and inspected before any water goes in

For most pools the practical answer is a black aluminum picket fence. It meets the picket spacing without looking like a cage, it does not rot at grade where a pool fence takes the most abuse, and the hardware is made for the job. Where privacy matters more than sightlines, a wood fence works as long as the rails go on the pool side.

Two things worth knowing before you call the city

Pool fences are not the same as regular fences. Your city's ordinary fence height limits are maximums. Pool enclosure heights are minimums, and the two bylaws can point in opposite directions on the same property. Our fence height guide covers the ordinary limits.

Check the bylaw, not the web page. We found at least one municipality whose own website states a maximum gap ten times larger than its bylaw says. Municipal summary pages are written for homeowners and get abbreviated. The bylaw is the document an inspector works from.

Sources: Toronto Municipal Code Ch. 447, Mississauga By-law 0191-2011, Brampton By-law 202-2011, Oakville By-law 2006-071, Vaughan Fence By-law 189-2020, Markham By-law 2015-96, Richmond Hill Ch. 973, Pickering By-law 6943/09, Ajax By-law 42-2025, Whitby By-law 8228-25, Oshawa By-law 79-2006, Clarington By-law 2000-105, Aurora By-law 6429-22, Newmarket By-law 2008-18, Whitchurch-Stouffville pool enclosure permits, Uxbridge pool enclosure permits, 2024 Ontario Building Code. Checked September 2026.