Tree Risk Assessment
A structured evaluation of a tree's likelihood of failure and what it would hit, with a written risk rating and mitigation options.
Last updated · by Michael Schuck, ISA Certified Arborist WE-15750A, ISA Certified Urban Forest Professional WE-15750AF
Who needs a tree risk assessment?
- Leaning, cracked or storm-damaged trees
- Trees near houses, driveways, play areas or neighbors
- Hazard-based permit applications
- Annual inspections for HOAs and property managers
What does a tree risk assessment include?
Written assessment with the ISA risk rating (likelihood of failure, likelihood of impact, consequences), photographs, targets, and prioritized mitigation from monitoring to removal.
How much does a tree risk assessment cost and how long does it take?
7 to 10 business days after the site visit.
$650 to $850 for a single tree with a written risk opinion; about $1,250 for five trees across adjoining parcels; $75 per additional tree added on site (prices as of October 20, 2026). The price is confirmed before the visit; there is no charge for a phone call to decide whether you need this at all.
How much does a tree risk assessment cost?
I charge $650 to $850 for a single tree with a written risk opinion. Five trees across adjoining parcels run about $1,250. Each tree added on site is $75. The fee is confirmed in writing before the visit.
What changes the price
Number of trees. Most of the cost is the visit and write-up, so each added tree costs far less than the first.
Level 2 or Level 3. The base price is a Level 2 assessment: a ground inspection of the whole tree with the ISA risk rating (likelihood of failure, likelihood of impact, consequences). Level 3 adds tools such as resistance drilling or sonic tomography. It is quoted separately, in writing, when Level 2 findings call for it; most trees do not need it.
Who will read it. The rating is the same whoever reads it; the document is not. An assessment for a city hazard application cites the city's criterion. Hayward, Los Gatos and San Jose ask for a certified arborist's hazard documentation; Los Gatos allows permit-free emergency removal only at a High or Extreme rating. For an insurance claim after a failure, the arborist report includes the risk assessment plus the sections the claim needs.
Timeline
Site visit within 7 days of the deposit; written assessment 7 to 10 business days after the visit. A 48-hour turnaround is available for single-tree reports at a surcharge agreed in advance.
When a risk assessment is the wrong product
For a removal permit, buy the arborist report, $750 to $1,250 for one to three trees. It contains the risk assessment and the permit sections, so buying both is paying twice. If a contractor quoted work and you want to know whether it is necessary, a second opinion at $375 to $450 answers that for less.
Questions about the price
Does the price include the city permit fee?
No. The city's permit fee is separate; each city page lists it.
Can you tell me the tree is safe for less?
No arborist can. The assessment states a risk level for a stated time frame and what would reduce it.
Is a risk assessment cheaper than an arborist report?
Yes, $650 to $850 against $750 to $1,250, because it answers one question: will this tree fail and hit something. If you also need permit paperwork, buy the arborist report.
How this fits the city's rules
Most cities approve removal of a hazardous tree faster when the application carries a risk assessment; several (Hayward, Los Gatos, San Jose) ask for a certified arborist's hazard documentation specifically.
Request a tree risk assessment
Questions
Is this the same as an arborist report?
A risk assessment focuses on failure potential. If you need removal justification, permit paperwork or insurance documentation, the arborist report includes the risk assessment plus those sections.
Can you say my tree is safe?
No arborist can. The assessment states a risk level for a stated time frame and what would reduce it.