An Arborist Report and Tree Preservation Plan inventory the trees on and near a site, assess their health, and set out which trees are protected, which can be removed, and what compensation or replanting is required. They are triggered by most site plan, subdivision, and rezoning applications and by municipal tree by-laws that protect trees above a certain size. They are prepared by a certified arborist and often determine building placement, because a protected tree’s root zone can be a no-build area.
A single protected tree can move a building. Municipal tree by-laws and site plan conditions give mature trees a protected root zone that construction cannot enter, so the arborist report is not a formality, it is a constraint map. Developers who site the building first and inventory the trees second routinely find a tree exactly where the foundation was meant to go.
An Arborist Report is a professional assessment of the trees on and adjacent to a site: species, size, health, and condition. The Tree Preservation Plan that accompanies it maps which trees are retained, which are removed, and the protection measures, fencing, root zones, for those that stay. Together they establish tree-related conditions of approval.
Most Ontario municipalities have a tree protection or private tree by-law that requires a permit to injure or remove trees above a threshold diameter. The arborist report supports that permit and quantifies the compensation, replacement plantings or cash-in-lieu, owed for approved removals.
An Arborist Report and Tree Preservation Plan are triggered by:
Not sure whether your site triggers a Arborist and Tree Preservation Plan? Enter your Ontario address and PreBuildIQ lists every study your specific property needs in 60 seconds.
Check my site →An Arborist Report is prepared by a certified arborist, commonly an International Society of Arboriculture (ISA) Certified Arborist, and for larger or ecologically sensitive sites by a consulting arborist or forester. Municipal urban forestry staff review the report and issue the associated tree permit.
A complete Arborist Report and Tree Preservation Plan typically contain:
| Factor | Typical range | What drives it |
|---|---|---|
| Consultant fee | $2,000 to $12,000+ | Number of trees, boundary trees, and whether monitoring is required |
| Preparation time | 2 to 5 weeks | Larger inventories and city-tree coordination add time |
| Municipal review | Weeks, tied to the tree permit | Circulation to commenting agencies and revision cycles |
Compensation for removed trees, whether replanting or cash-in-lieu, is a separate cost from the report itself, and in cities with aggressive canopy targets it can run to tens of thousands of dollars. Price the compensation, not just the study.
Tree by-laws differ sharply by municipality. Toronto protects private trees above 30 cm diameter and city trees of any size, with significant compensation. Many suburban municipalities protect trees above a set diameter or within defined areas only. Vaughan, Oakville, Mississauga, and others each set their own thresholds and replacement ratios, so the same tree removal can be free in one municipality and cost thousands in the next.
An arborist report is a certified professional’s assessment of the trees on and near a site, their species, size, health, and condition, paired with a Tree Preservation Plan showing which trees are retained, which are removed, and the protection measures. It supports the tree removal permit and sets the compensation owed for approved removals.
You need one for most site plan, subdivision, and rezoning applications on treed sites, and whenever you propose to remove trees protected under a municipal tree by-law. Development adjacent to woodlands, ravines, or city-owned trees, and sites with boundary trees, also trigger the requirement.
An arborist report typically costs between $2,000 and $12,000 or more, driven by the number of trees, the presence of boundary or city trees, and whether construction-phase monitoring is required. Compensation for removed trees, replacement planting or cash-in-lieu, is a separate and sometimes larger cost.
Usually yes. Most Ontario municipalities have a tree protection or private tree by-law requiring a permit to remove or injure trees above a threshold diameter, and city-owned trees are protected regardless of size. The arborist report supports the permit application and quantifies replacement or cash-in-lieu compensation.
A tree preservation plan and arborist report are prepared by a certified arborist, commonly an ISA Certified Arborist, or a consulting arborist or forester for larger sites. Municipal urban forestry staff review the report and issue the associated tree permit.
PreBuildIQ identifies every required study, including the Arborist and Tree Preservation Plan, for any Ontario address in 60 seconds, with the trigger and terms of reference for your specific municipality.
Run a site report →