The two Cambridge tracks
- Private trees on a lot are regulated under Cambridge’s Tree Protection Ordinance.
- Public shade trees remain under Chapter 87 and City Arborist / Tree Warden control. Do not let a private crew treat a street tree like a private-lot permit.
Permit thresholds
- A Significant Tree starts at 6 inches DBH.
- An Exceptional Tree starts at 30 inches DBH and carries a 1.5x multiplier in Cambridge’s mitigation math.
- Trees below 6 inches DBH do not need a removal permit under the ordinance.
Special-circumstance paths
- Dead tree: Form A.
- Dangerous tree: Form A plus ISA risk-assessment support.
- Removal benefits other Significant Trees: Form B.
- Significant impact to an existing structure: Form C plus City Engineer coordination.
If none of those fit, Cambridge expects a mitigation path with replacement trees, fund payment, or both.
Mitigation mechanics
- Cambridge’s published mitigation rate is $850 per inch DBH.
- Exceptional Trees are priced at 1.5x, effectively $1,275 per inch DBH.
- Properties with the City’s Residential Exemption pay 10% of the full mitigation fee.
- Replacement trees can reduce the payment, but replacement trees are tracked for 10 years and need a permit to remove regardless of size.
Construction track
- Any permitted construction on a lot with Significant Trees should be scoped under Cambridge’s duty-of-care requirements.
- In practice, that means a Tree Protection Plan whenever building, utility, driveway, or grading work can affect retained Significant Trees.
- Large projects on Cambridge’s zoning triggers require a formal Tree Study package, filed in advance with the City Arborist.