Unlike the UK, Canada doesn't have one dominant national standard that every municipality points to for a pre-development tree assessment. What a surveyor actually has to satisfy is a layer of three things: the Canadian Standards Association's CSA Z7700 (tree risk assessment and urban forest standard), ANSI A300 (widely used across North America for tree care operations and commonly referenced for pruning and root-zone work even though it's a US standard), and — the part that actually decides whether a permit gets issued — the municipality's own tree protection bylaw.
That third layer is where most of the real variation lives, and it's the one out-of-town software can't hard-code away.
The municipal bylaw is the actual gate
Toronto, Vancouver, Ottawa, and dozens of smaller municipalities each have their own private-tree and street-tree bylaws, with their own permit thresholds (often keyed to trunk diameter at a specified height), their own definitions of what counts as "injury" to a protected tree, and their own penalty schedules. A survey written to a generic national template and dropped into a Toronto permit application will get queried if it doesn't speak the bylaw's specific language — diameter measured at the height the bylaw specifies, not the height a different standard would use.
The practical implication: check the municipality first, standard second. A surveyor who knows the local bylaw's exact wording gets through review faster than one who submits a technically excellent CSA Z7700 report that doesn't map onto the permit officer's checklist.
Root zone protection, without a single national formula
Where BS 5837 gives the UK a single Root Protection Area formula, Canadian practice borrows more informally from ISA (International Society of Arboriculture) best-management practice: a critical root zone commonly estimated at roughly 12 inches of radius per inch of trunk diameter, adjusted for species and site conditions rather than applied as a rigid multiplier. Several municipalities publish their own version of this in their bylaw guidance — always check whether the local authority has published its own root-zone formula before defaulting to the generic ISA figure.
What actually gets checked
A permit reviewer is checking three things in practice: does the tree inventory match what's on the site plan, does the stated trunk diameter match the bylaw's specified measurement height, and does the protection fencing on the drawing actually correspond to a defensible root-zone calculation rather than an arbitrary line. Get those three consistent and a Canadian tree permit moves about as fast as any other jurisdiction's — the friction almost always comes from a mismatch between the survey and the specific bylaw it's being submitted against, not from the underlying arboriculture.
None of this is legal advice — always confirm the current bylaw with the municipality before submitting. This is the kind of jurisdiction-specific detail tree·canopy is built to keep straight: dictate the survey once in the field, and the record carries the measurement height and species data a Canadian permit reviewer is actually going to check.