Not every worrying-looking tree needs a formal report. A big maple that drops the odd dead branch in a windstorm doesn’t need one just because a neighbour mentioned it looks “a bit much” this year. A dead tree over a shared driveway, a lean that’s gotten worse since spring, or a letter from your insurer asking about a specific tree are different situations, and they usually do. The difference comes down to what happens if you’re wrong, and whether anyone besides you needs convincing.
You Need One When Something Else Is Riding on the Answer
A tree risk assessment is worth paying for when the outcome has to hold up to someone other than you: a neighbour who disagrees, an insurer deciding a claim, a city reviewing a permit, or a court. If the only question is “should I have this pruned,” you don’t need a formal report to answer it.
Three situations push a tree from “keep an eye on it” into “get it assessed”:
- A boundary or neighbour dispute where the other side doesn’t accept your read on the tree’s condition.
- A fallen tree, or one you’re worried will fall, where an insurance claim is or might become involved.
- A dead, dying, or hazardous tree in a municipality where the removal permit process asks for documentation of that condition.
Each of those has its own reason a homeowner’s opinion isn’t enough on its own.
A Neighbour Dispute Needs a Documented, Independent Finding
If a shared or boundary tree is in dispute and the other owner won’t agree it’s a problem, your opinion and theirs cancel each other out. What moves the situation is an independent assessment on record.
That’s exactly what happened in Freedman v Cooper, a 2015 Ontario Superior Court case (2015 ONSC 1373) involving a boundary maple that had already lost a third of its canopy in an ice storm. Two separate arborists documented the continuing risk. The co-owner who objected to removal still wouldn’t consent, and the court applied nuisance law over the Forestry Act’s consent requirement, ordering that owner not to interfere. The documentation carried the case, not the argument on either side.
The stakes justify the paperwork. An Ontario court has put the cost of damaging a tree that wasn’t entirely yours to remove in the six figures once replacement, restoration, and lost screening value get counted. A hazard finding you can point to, rather than a claim either neighbour just asserts, is the difference between resolving a dispute and losing one. Our guide to neighbour tree disputes in Ontario covers the legal framework these cases sit inside.
An Insurance Letter or a Fallen Tree Changes the Calculation Too
Home insurance generally covers the cost of damage and debris removal when a tree falls, according to the Insurance Bureau of Canada. But there’s a carve-out: if the tree had been dead for a while and nothing was done about it, that’s negligence, and an insurer may try to recover the cost from you instead of just paying the claim.
The IBC’s own prevention advice closes that gap directly: have a qualified professional regularly inspect your trees, especially if they show signs of damage or illness, and remove the ones that pose a risk. A dated assessment is what that inspection looks like on paper. Rate the tree healthy and it fails anyway in a storm that took out other trees nearby, and that’s a documented, unpredictable event. Flag a problem and nothing gets done, and that’s a different conversation with the insurer, but at least it’s grounded in what was actually known and when.
As Rates.ca reported, IBC’s Rob de Pruis put it plainly: “Just because you own a tree doesn’t mean that you’re legally liable for damages that it could have caused.” An assessment is what turns that “could have” into a documented answer.
Some Cities Waive the Paperwork, Not the Proof
If a dead or hazardous tree is the reason you’re removing it, the exemption from the standard permit process depends entirely on which municipality you’re in, and most of them still want the condition documented somehow.
Toronto’s Chapter 813 exempts a 100%-dead tree from needing a full permit, but the city’s permit exception confirmation has to be in hand before removal, unless the tree is an immediate hazard, in which case it can come down first and get documented after. Vaughan’s By-law 177-2025 waives the arborist report for a dead, hazardous, or EAB-affected tree, but the permit itself is still required. East Gwillimbury’s By-law 2024-077 is the most permissive of this group: dead, dying, or hazardous trees are exempt outright, and the whole bylaw carries no application fee at all.
Newmarket’s By-law 2022-10 splits the same category three ways: a dead or dying tree needs a permit but no report, a hazardous tree needs a report with no fee and no replacement planting, and a genuine emergency needs only an email and photos, no permit at all. Significant and Heritage Trees are never exempt, no matter the condition. Oakville’s By-law 2017-038 waives the application fee, not the application itself, for a dead tree (confirmed by the town or a certified arborist), a high-risk tree, an ash tree hit by emerald ash borer, or invasive buckthorn.
That confirmation requirement is the pattern across most of these cities: “dead” or “hazardous” as a category the city will act on almost always needs someone qualified to say so, even in the municipalities that don’t charge for the privilege. Our self-triage guide for assessing tree risk walks through the visible signs worth a closer look before you get to that point, and our post on getting a dead tree documented before storm season covers why that documentation is worth having on hand ahead of the first real windstorm, not after.
What an Assessment Actually Involves
The formal version of this is TRAQ, the Tree Risk Assessment Qualification, a training and testing program the International Society of Arboriculture administers for arborists who already hold an ISA credential (or equivalent). It’s a two-day in-person course plus a half-day exam, renewed by retraining and retesting every seven years, not just paid for once.
ANSI A300 (Part 9), the tree risk assessment standard, sets out three levels of inspection. A limited visual assessment is done from one specified perspective, like a foot or vehicle patrol past the property. The next level up is a 360-degree, ground-based visual inspection of the crown, trunk, trunk flare, above-ground roots, and site conditions, evaluated against whatever the tree could hit if it failed. Beyond that, arborists move to techniques like drilling, increment boring, pull testing, or radiation assessment, used when the ground-based inspection alone can’t pin down how far a problem extends.
What comes out the other end is a rating, not a description. TRAQ combines the likelihood the tree fails, the likelihood something gets struck if it does, and the consequences if it did, into one rating: low, moderate, high, or extreme. That’s the rating a city reviewer, an insurer, or a lawyer can act on.
What Drives the Cost
There’s no fixed price for a tree risk assessment, on our site or anywhere else worth trusting. The number of trees, the access and complexity of the site, how the report will be used, and how urgently you need it all move the cost. A report headed to a lawyer or an insurer takes more documentation than one for your own peace of mind, and a same-week assessment ahead of a storm costs more than one on a normal schedule.
If you’re just deciding whether a healthy-looking tree needs a prune this fall, you likely don’t need to spend on a formal assessment at all. Save it for when the answer has to satisfy someone besides you.
Getting the Right Read Before You Need It
If a neighbour, an insurer, or a city permit office is going to be looking at your tree’s condition, get the assessment done before that conversation starts, not in the middle of it. A tree risk assessment from our ISA Certified consulting arborists follows the TRAQ methodology and gives you a documented rating you can hand to whichever party is asking. Not sure your situation calls for one? Contact us with a description of the tree and what’s prompting the question, and we’ll tell you before you book a site visit.