You’re probably here because you’ve got a tree that worries you, and you’re wondering if you can just document what you’re seeing yourself. How to write a tree hazard assessment Florida homeowners can actually rely on starts with a piece of information most guides skip: writing one yourself, however carefully, doesn’t carry the same weight as a qualified professional’s report. That’s not a technicality — it’s the difference between documentation that holds up and documentation that doesn’t. Here’s what actually goes into a real one, and why the distinction matters.
Quick disclaimer before we continue: this reflects publicly available industry standards and statutory references as of the date above, not legal advice. Confirm current requirements with a qualified arborist or your local permitting office before relying on any assessment for a legal or insurance purpose.
What a Legally Valid Tree Hazard Assessment Actually Requires
A legally valid Florida tree hazard assessment must be produced by an ISA-certified arborist or Florida-licensed landscape architect, following the ISA’s Best Management Practices — Tree Risk Assessment (2017) protocol.
Here’s the credential requirement, stated plainly: only an ISA-certified arborist or a Florida-licensed landscape architect can produce a tree risk assessment that carries real legal or financial weight. That’s not an arbitrary preference — it’s built into how the protocol itself is structured, and it’s why Fla. Stat. §163.045 specifically requires this exact documentation standard for its removal exemption. If you want the full breakdown of that exemption and when it applies, our guide to Florida Statute 163.045 covers it in detail. This page focuses on something different: what actually happens during a proper assessment, so you understand what you’re getting — or what you’re missing if you skip it.
The controlling standard is the International Society of Arboriculture’s Best Management Practices — Tree Risk Assessment, Second Edition (2017), built on ANSI A300 Part 9. It’s not a Florida statute in itself — it’s a professional industry standard that Florida law happens to reference as the required protocol for certain legal purposes.
Who’s Exempt From Needing a Professional Assessment — and Who’s Not
Low-Stakes, No-Target Situations
A homeowner’s own observation of a tree may be sufficient when no permit exemption, insurance claim, or liability dispute depends on the outcome.
If you’re just deciding whether to schedule a routine trim, or you’re curious about a tree with no real safety concern, your own judgment is fine. Nobody’s requiring documentation for casual yard maintenance.
Anything Tied to a Permit Exemption, Insurance Claim, or Liability Dispute
A homeowner cannot substitute their own assessment for a qualified professional’s when the outcome involves a permit exemption, insurance claim, or liability question — no self-written document satisfies these requirements.
The moment documentation actually matters — a §163.045 permit exemption, an insurance claim after storm damage, a liability question after a tree fails — a homeowner’s own write-up doesn’t substitute for the real thing. This is the line most competitors never draw clearly, and it’s exactly where people get burned.
What Happens If You Rely on a Non-Qualifying Assessment
Relying on a homeowner-written or unqualified assessment for a permit exemption or insurance claim typically results in the same outcome as having no documentation at all — the claim or exemption gets denied.
Here’s the honest version: an assessment that doesn’t meet the standard doesn’t just weaken your position, it usually fails outright. If you’re claiming the §163.045 exemption with your own observations instead of a qualified arborist’s documented risk assessment, your local government isn’t obligated to accept it — you’re exposed to the same permit violation as if you’d removed the tree with no documentation whatsoever. Insurers work the same way. A claim adjuster reviewing storm damage wants a credentialed assessment, not a homeowner’s photos and a written opinion, however reasonable that opinion might be.
How a Professional Tree Risk Assessment Actually Gets Written — Step by Step
A professional Florida tree hazard assessment follows a structured process: site inspection, rating the likelihood of failure, rating the likelihood of impact, and combining both with consequence severity to produce a final risk rating.
This is the part almost nobody explains in plain language. Here’s what a qualified arborist actually does, step by step.
Step 1 — Site and Tree Inspection
The first step of a tree risk assessment is a structured visual inspection covering crown vigor, trunk decay signs, and root collar condition.
The assessor examines the crown for vigor — foliage color, density, branch dieback. They check the trunk (the bole) for decay signs: cavities, wounds, fungal fruiting bodies, cracks, unnatural leans. They inspect the root collar and visible roots for similar structural concerns. This is the raw data-gathering stage everything else builds on.
Step 2 — Rating Likelihood of Failure
Likelihood of failure in a tree risk assessment is categorized as improbable, possible, probable, or imminent, based on the structural conditions observed during inspection.
Based on what the inspection turns up, the assessor rates how likely the tree or a specific part of it is to actually fail, using four defined categories: improbable, possible, probable, or imminent. This isn’t a guess — it’s tied directly to the structural defects and conditions documented in Step 1.
Step 3 — Rating Likelihood of Impact
Likelihood of impact rates whether a tree failure would strike a target such as a person, vehicle, or structure, categorized as very low, low, moderate, or high.
Separately, the assessor rates how likely a failure would actually hit something of value — a house, a car, a person walking below. This gets its own rating: very low, low, moderate, or high, depending on how often a target is present in the tree’s fall zone.
Step 4 — Combining Into a Risk Rating
A tree’s final risk rating is determined by combining likelihood of failure and impact through a first matrix, then combining that result with consequence severity through a second matrix to produce a rating of Low, Moderate, High, or Extreme.
This is where the two ratings actually become useful. The assessor runs likelihood of failure and likelihood of impact through a first matrix to get a combined likelihood rating. That result then gets combined, through a second matrix, with the consequences of failure — rated as negligible, minor, significant, or severe — to produce the tree’s final overall risk rating: Low, Moderate, High, or Extreme. This two-matrix system is deliberate. It forces the assessor to weigh each factor independently before combining them, rather than jumping straight to a gut-feeling conclusion.
Recent Changes You Should Know About (2024–2026)
ISA periodically updates its official tree risk assessment forms and terminology, so confirming an arborist is using the current edition matters for documentation validity.
The ISA revises its official assessment forms from time to time, and current copies in circulation reflect updates through 2025. If you’re relying on an assessment for something with legal weight, it’s worth confirming the arborist is working from the current form and terminology tied to the 2017 BMP edition still referenced by Florida law, rather than an outdated version.
When to Call a Professional
A certified arborist performing a full tree risk assessment covers every step of this process directly, producing documentation valid for permit exemptions and insurance purposes.
Everything walked through above — the inspection, the two-matrix rating system, the final risk classification — is exactly what our hazardous tree assessment service performs. If you’re weighing whether a tree needs documentation that will actually hold up, that’s the starting point.
FAQs
A homeowner can note their own observations, but it won’t carry legal or insurance weight. Anything tied to a permit exemption, insurance claim, or liability question requires an assessment from an ISA-certified arborist or Florida-licensed landscape architect.
It must be produced by a qualified professional following the ISA’s Best Management Practices — Tree Risk Assessment (2017) protocol, the specific standard referenced by Fla. Stat. §163.045.
TRAQ (Tree Risk Assessment Qualification) is the ISA’s structured methodology for evaluating tree risk, using a two-matrix system that combines likelihood of failure, likelihood of impact, and consequences of failure into a final risk rating.
Likelihood of failure rates how probable it is that a tree or tree part will actually break, ranging from improbable to imminent. Likelihood of impact rates how probable it is that a failure would strike a person, vehicle, or structure, ranging from very low to high.
By combining likelihood of failure and likelihood of impact through a first matrix, then combining that result with consequence severity through a second matrix, producing a final rating of Low, Moderate, High, or Extreme.
Only if it’s performed by a qualifying professional following the required BMP protocol. A homeowner’s own assessment does not satisfy the statute’s documentation requirement.
Generally, no. Insurers typically require a credentialed arborist’s documented assessment for claims involving tree damage or removal decisions.
An ISA Certified Arborist credential or a Florida license to practice landscape architecture, along with familiarity with the current BMP Tree Risk Assessment protocol.
Costs vary by tree size, site complexity, and scope of the assessment. For a fuller picture of related service pricing, see our tree removal cost guide.
Final Word
Writing a tree hazard assessment isn’t really something a homeowner does alone — it’s a structured, credentialed process built around two matrices that turn observation into a defensible risk rating. If you’re relying on documentation for anything more than personal peace of mind, the qualification behind it matters as much as the content itself. Know what the process actually involves, and you’ll know exactly what to expect from whoever you hire to do it.
