Tree Risk Assessment in MA — When You Need One & What It Costs

Here is a question I get about once a week: "Keith, is that tree going to fall on my house?" The honest answer is, I do not know from your kitchen window. Neither does your neighbour who "knows about trees." A tree risk assessment is how you actually find out — and it is cheaper than most people think, and a lot cheaper than the alternative.

I have been doing tree work in Massachusetts since 1995. In that time, I have talked more people out of removing trees than into it. A proper assessment is not a sales pitch for removal. It is a diagnostic. Think of it like getting an X-ray before deciding on surgery — sometimes you need the operation, sometimes you just need a brace.

What a Tree Risk Assessment Actually Is

A tree risk assessment is a formal evaluation of a tree's likelihood of failure and the potential consequences. It follows a standardized methodology developed by the International Society of Arboriculture (ISA). The assessor evaluates the tree's structure, health, and environment, then produces a risk rating.

There are three levels of assessment:

• Level 1 — Limited Visual: A walk-by inspection from the ground. Quick, inexpensive, good for screening multiple trees on a large property. Catches obvious hazards — dead trees, severe lean, major bark separation.
• Level 2 — Basic Assessment: A thorough ground-level inspection of a single tree. Includes visual inspection of the trunk, roots, canopy, and surrounding site. This is what most homeowners need. The arborist uses a mallet to sound the trunk, looks for fungal conks, checks root flare, and evaluates the overall structure.
• Level 3 — Advanced Assessment: Includes specialized tools — resistograph (drills into the trunk to measure wood density), sonic tomography (maps internal decay), root crown excavation. Used for high-value trees, legal cases, or when Level 2 is inconclusive.

Most residential calls need a Level 2. A certified arborist spends 30 to 60 minutes per tree and gives you a written report with a risk rating and recommendations.

When You Actually Need One

Not every tree needs a formal assessment. Here is when it earns its keep:

1. The Tree Looks Different Than Last Year

A new lean. Dead branches that were not there last summer. Bark peeling off in sheets. Mushrooms growing at the base. These are the signals. Trees change slowly — when something changes fast, pay attention. A tree that stood straight for twenty years and is now tilting after a wet spring has a root problem. That is not a "wait and see" situation.

2. It Is Close to Something You Care About

A dead tree in the middle of a two-acre field is a wildlife habitat. A dead tree six feet from your bedroom window is a hazard. The risk equation has two parts: likelihood of failure and consequences of failure. A tree over your roof, your kid's play set, your driveway, or the neighbour's fence has high consequences regardless of its health.

3. Before You Buy a Property

I have done assessments for home buyers in Lexington, Concord, and Bedford where the report saved them five figures. One property had a 70-foot dead ash tree leaning toward the garage — the seller had no idea, and the home inspector did not catch it. The buyer negotiated the removal into the sale price. That is a $2,000 assessment saving a $3,000 removal and a potential insurance claim.

4. After a Major Storm

Nor'easters, ice storms, and microburons do invisible damage. A tree can look fine from the street but have a cracked root plate or a split leader that will fail in the next wind event. After any storm that brings down trees in your neighbourhood, the standing trees nearby deserve a look. We see this every storm season.

5. Your Insurance Company Asks for One

This is becoming more common. Some insurers are requiring arborist reports for properties with large trees within falling distance of structures. If your carrier asks, get the assessment — it is cheaper than losing coverage.

What the Arborist Is Actually Looking At

When I walk a tree for a risk assessment, I am checking six things:

Trunk Integrity

Cracks, cavities, included bark (where two stems grow together with bark trapped between them), and previous wound response. A cavity on a 30-inch oak is different from a cavity on a 12-inch birch — the ratio of compromised wood to sound wood matters.

Root Condition

This is where most people miss the warning signs. Mushrooms at the base (especially honey fungus or chicken-of-the-woods) indicate root rot. Soil heaving on one side means the root plate is shifting. Severed roots from construction or trenching weaken the tree's anchor system. You cannot see most of the roots, so we look for these surface indicators.

Canopy Health

More than a third of the canopy dead? That tree is in decline. Dead branches high in the crown are especially dangerous — they fall without warning, often in calm weather. I have seen a 200-pound dead oak limb let go on a perfectly still July afternoon. Gravity does not care about the forecast.

Lean and History

A tree that has leaned the same way for thirty years is probably fine. A tree that developed a lean last winter has a root problem. We check the soil for heaving, look at the trunk for stress wood (thickened growth on one side), and ask the homeowner about the timeline.

Target Zone

What is under and around the tree? A house, a power line, a playground, a pool, a parked car — each adds consequence to the risk equation. A tree rated "moderate risk" in an open field might be "high risk" if the same tree is over a bedroom.

Species-Specific Patterns

Some species fail in predictable ways. Ash trees infested with emerald ash borer become brittle and snap. Silver maples have weak branch unions. White pines uproot in saturated soil. Knowing the species helps predict the failure mode.

What It Costs (Real Numbers)

Assessment Type	Cost	What You Get
Single tree, Level 2 (ground-based)	$150 – $350	Verbal or brief written report with risk rating and recommendations
Single tree, Level 2 with full written report	$300 – $600	Detailed written report with photos, risk matrix, and action plan
Multi-tree property (5–15 trees)	$500 – $1,000	Priority-ranked inventory with risk ratings for each tree
Large estate or commercial site (15+ trees)	$1,000 – $1,500+	Full property report with management plan
Level 3 advanced (resistograph, tomography)	$500 – $1,200 per tree	Internal decay mapping, used for high-value or legally significant trees

Those numbers come from what arborists charge in Middlesex County. We do not do the assessments ourselves — we are the crew that does the work after the assessment recommends it. But I can tell you what fair pricing looks like because I see these reports constantly.

Assessment vs. Free Estimate: The Difference Matters

A free estimate is a price quote. I come out, look at the tree, and tell you what it costs to remove or prune it. That is useful if you have already decided the tree needs work.

A risk assessment is a diagnostic. The arborist tells you whether the tree needs work at all, what kind of work, and how urgent it is. Sometimes the answer is "the tree is fine, leave it alone." Sometimes it is "prune these three branches and check back in two years." Sometimes it is "this tree is coming down on its own — schedule the removal now while it is controlled."

The biggest difference is who benefits. A free estimate benefits the tree company — they get the job. A risk assessment benefits you — you get the truth. I have built my whole career on telling people when they do not need me. The arborist assessment is the formal version of that.

What Happens After the Assessment

The report will include one of these recommendations:

• No action needed. The tree is structurally sound. Monitor it annually or after major storms.
• Pruning recommended. Remove deadwood, improve structure, reduce end-weight on heavy limbs. This is the most common outcome — pruning costs a fraction of removal.
• Monitoring recommended. The tree has a defect that is not currently dangerous but needs watching. Re-inspect in 12 to 24 months.
• Removal recommended. The tree is structurally compromised and poses an unacceptable risk. This is when you call us.
• Immediate action required. The tree is an imminent hazard. This is the "call someone today" category.

Nine out of ten assessments I see land in the first three categories. The default assumption that every problem tree needs removal is wrong — and it costs homeowners thousands of dollars they did not need to spend.

How to Find a Qualified Assessor

Look for these credentials:

• ISA Certified Arborist — the baseline certification. Requires passing an exam and maintaining continuing education.
• ISA Tree Risk Assessment Qualification (TRAQ) — the specific credential for risk assessment. This is the one you want. It means the arborist has completed a multi-day training on the ISA risk assessment methodology.
• Massachusetts Licensed Arborist — required by state law for anyone offering arborist services.

Ask for a sample report before hiring. A good report includes photos, a clear risk rating, specific recommendations, and a timeline. A report that just says "tree is hazardous, recommend removal" without evidence is not worth the paper it is printed on.

The Bottom Line

A tree risk assessment is the difference between guessing and knowing. It costs less than most people expect, it often saves trees that did not need to come down, and it catches problems before they become insurance claims. If you have a tree that concerns you, get the assessment first — then call us if the report says removal is the right call.

If you are not sure whether your tree needs an assessment or just a look from someone who knows what to look at, call us at (978) 375-2272. We will tell you honestly whether you need a formal assessment or whether the tree just needs a pruning. We have been doing that since 1995. Some of our best work is talking people out of work they did not need.