Tree guides
When is an arborist report needed?
The report supports the application. Its purpose and required professional qualification depend on the city and project.
What the city asks for
A report may assess condition, justify removal, map protected trees or explain construction impacts. Check the application stream first.
For a non-development private-tree removal application, Vancouver asks for an arborist report prepared by an ISA-certified arborist plus a site plan. Development applications involving trees 20 cm or larger also require arborist information under the City’s tree-protection rules.
Toronto’s application to remove or injure a protected private or City tree requires an arborist report describing location, species, size, condition, structural integrity, disease/infestation and health.
Ottawa uses a Tree Information Report for many tree permits. The report must be prepared by an arborist, forester or similarly qualified professional. A short TIR can support a condition-based removal; a full TIR is used for infill work, while Planning Act applications use a Tree Conservation Report.
Expert-report requirements are borough- and reason-specific. The city portal lists expert reports among the documents required in many removal situations, while some dead-tree cases can follow a simpler evidence path.
What a useful report answers
- The tree: location, ownership, measured size and condition.
- The work: proposed removal or impact on roots, branches and protection zones.
- The evidence: why removal is requested and whether retention is reasonable.
Hazard or construction?
- Condition-based report: explain death, decline, structural defects or a specific conflict.
- Construction report: locate retained and removed trees; show excavation, grading, mitigation and protection through the project.
Before hiring an arborist
- Open the municipality’s current application checklist first.
- Confirm whether the city specifies ISA certification, a forester or another professional qualification.
- Ask whether the report is for condition, removal, infill, site plan or another development stream.
- Make sure ownership and boundary trees are addressed; a survey may be needed.
- Have the report match the same drawings and scope used in the building/development application.
See the detailed local pages for Vancouver, Toronto, Ottawa and Montréal.
Official sources
Sources were re-checked for this guide on September 29, 2026. Municipal bylaws, fees, exemptions and development conditions can change. Use the linked municipality for the current rule before work begins.
Independent information, not legal or arboricultural advice. Ownership, site conditions and professional assessments can change the answer.