Backyard construction guide
Plan the Tree Before You Finalize the Backyard ARU
Excavation, utility trenches, grading, access and material storage can affect roots well beyond the trunk. Coordinate the tree plan before fixing the building footprint.
The by-law’s Critical Root Zone is a regulatory definition. A project-specific Tree Protection Zone or barrier may be determined differently through the approval process.
Design-stage checklist
Map these conflicts before choosing the ARU location
Building footprint
Show the trunk, canopy and root-protection area—not only the proposed walls.
Excavation and grading
Root excavation, grade changes and soil compaction can constitute tree injury.
Utilities and drainage
Route water, sewer, hydro and drainage away from sensitive root areas where feasible.
Access and staging
Keep machinery, bins, soil and materials outside the protected area.
Which rules may apply?
Size, location and project impact all matter
- Distinctive Tree: A private tree 50 cm DBH or larger within the Urban Growth Boundary, excluding a Tree Protection Area.
- Tree Protection Area: Trees of any size can be regulated inside a mapped Tree Protection Area.
- Building approval: London advises applicants that removal or damage to public or private trees may require separate approval.
- Boundary tree: A trunk growing on the property boundary can be jointly owned under Ontario’s Forestry Act.
Construction controls
Protect the tree before equipment arrives
- Install barriers before construction and maintain them until work is complete.
- Use barriers at least 1.2 m high, following the City’s homeowner guidance.
- Do not park, fuel, clean or operate equipment within unapproved root areas.
- Do not stockpile soil or construction materials under the canopy or within protected areas.
The TCCP is not a general construction subsidy
Some preservation work may qualify if it meets program rules and is approved before work begins. Work required by a City Order is not eligible. Ask the City about the specific ARU-related scope rather than assuming reimbursement.
Primary sources
Check the official rules
Program decisions are made by the City of London. These sources were reviewed on July 29, 2026.