After Toronto's '100-year storm': which repairs need a permit, and which leave no trace

On Wednesday, September 2, a line of storms came at Toronto from the north — the wrong direction, according to CP24's meteorologist, which is why the Niagara Escarpment didn't take the edge off it the way it usually does. Environment Canada's preliminary numbers: 118.1 mm of rain in North York, 105.9 mm in Scarborough, hail up to 6.5 cm across, and radar-estimated winds above 130 km/h. Toronto Fire logged close to 1,500 calls in 24 hours, its busiest day since the 2013 ice storm. The City Manager called it a "100-year storm."

Now comes the part that shows up in property records for years: the repairs. Some of them need a City permit. Most don't. Knowing which is which matters whether you're the one fixing a house this month or the one buying it next spring.

This is general information, not legal or insurance advice. Confirm your own situation with Toronto Building, your insurer, or a professional.

What you can fix without a permit

Toronto Building's own list of permit-exempt work covers a lot of what a storm breaks on a house. As long as there's no structural change, you don't need a permit to:

• Replace roofing material — re-shingling a roof that lost shingles to hail or wind.
• Replace a window or door in its existing opening (detached, semi, or row house with a single unit) — the size and location of the opening can't change.
• Re-clad a house with non-combustible material other than brick or stone veneer.
• Do waterproofing repairs to a basement, or replace insulation.
• Install a sump pump, or repair and replace plumbing fixtures.
• Replace a furnace, boiler, or hot water tank — relevant if yours sat in a foot of water on Wednesday night.

That's good news for speed. It's also why so much storm damage vanishes from the record: a house that lost half its roof and had its basement gutted can be fully repaired with zero permits on file, if it was done as like-for-like.

What does need one

The line is structure. A permit is required to:

• Repair or replace roof structure — rafters, trusses, or sheathing, not just the shingles on top. If wind took the roof deck with it, that's permit work.
• Demolish or remove any portion of a building, including a collapsed porch, garage, or deck.
• Alter walls, or add or enlarge window and door openings.
• Install or modify heating or plumbing systems — new ductwork or drain lines, as opposed to swapping a fixture.
• Install a backwater valve. This one matters most after a flood, and the City will pay for most of it: the Basement Flooding Protection Subsidy covers up to 80% of the cost, capped at $1,600 per valve, with a permit and inspection required.

A house that lost half its roof can be fully repaired with zero permits on file. A house that installed a backwater valve can't.

That asymmetry is the whole point for anyone reading a property record. The permit history won't tell you a house flooded. It will tell you whether a previous owner did the one thing that most reliably prevents the next flood, and whether the City inspected it.

The tree in the yard

A lot of Wednesday's damage was trees — on cars, on fences, on roofs. The rules are simple but not obvious:

• Any private tree 30 cm or more in diameter is protected under Toronto's private tree bylaw, and every tree in a ravine-protected area is protected regardless of size. Removing one normally requires a permit.
• If an arborist deems the tree an imminent hazard, no permit is needed — but the City asks you to photograph it and report it through 311, so there's a record if a neighbour later complains that a healthy tree came down.
• The City will not inspect or maintain private trees. Hiring the arborist is on you.
• A neighbour's tree on your roof is a civil matter between the two of you, not a City one.

Leave the debris and someone complains? Municipal Licensing & Standards can investigate and issue a Notice of Violation or an Order to Comply; if the City ends up doing the cleanup, the cost lands on your property tax bill.

Insurance, briefly

The Insurance Bureau of Canada's post-storm advice: photograph everything before you touch it, keep receipts, and don't throw out damaged items until they're documented. The catch most people discover too late is that sewer backup and overland flood coverage are optional add-ons on a standard home policy. If water came up through the floor drain and you never bought the rider, the claim may not exist.

If you're buying a house this fall

A seller in Ontario doesn't have to volunteer that the basement took on water on September 2. So do the work yourself:

• Pull the address's permit history. A plumbing permit for a backwater valve is a good sign. A structural roof or demolition permit opened in September 2026 tells you exactly what happened — and whether it's closed.
• Check orders and violations and bylaw investigations for anything tied to debris, unsafe structures, or property standards.
• Use the environment tool to see what's near the address, and ask directly about the storm. A fresh coat of basement paint in a North York listing is a question, not an answer.

Check any address

Start with the property snapshot for the full record in one view, or go straight to permits. If you already own, monitor your address and you'll see every new permit, inspection, and order as it lands — including your own repairs, which is a useful thing to have on file the next time a 100-year storm comes around in fewer than 100 years.