Co-op, HOA and Condo Boards: Managing Tree Risk and Liability on Your Property
If you sit on a co-op or condo board in the New York metro area, you've probably spent meetings on the boiler, the roof, Local Law 11 facade work, and the elevator modernization. The trees on your property almost certainly haven't come up. That is until a limb comes down on a parked car, or a resident's child, or the sidewalk you're statutorily responsible for maintaining. At that point the conversation shifts very quickly, and the first question your attorney and insurance carrier will ask is: what did the board know about the condition of that tree, and when did it know it?
This is the core of tree risk liability in New York. Property owners are not strictly liable for every tree failure. Trees fall in storms, and that alone doesn't create negligence, it’s considered an ‘act of god.’ What creates exposure is constructive notice: the legal doctrine that says you are responsible for defects you knew about, or reasonably should have known about, and failed to address. A board that has never had its trees professionally evaluated is in a far weaker position after an incident than a board that has a current inventory, a documented inspection cycle, and a paper trail of recommendations acted upon. The documentation is the protection. Without it, a plaintiff's attorney gets to tell the jury whatever story they want about what a reasonable board should have known.
The tree inventory: your foundational document
Before you can manage risk, you need to know what you have. A professional tree inventory is a tagged, mapped, and cataloged record of every significant tree on the property. For each tree it captures species, diameter at breast height (DBH), approximate height, location (typically GPS-tagged and plotted on a site map), condition rating, identified defects, risk rating, what the tree could hit if it failed , and recommended actions with priorities.
For a typical Manhattan co-op with a handful of courtyard trees, an inventory might cover fifteen or twenty specimens. For a garden-style condo complex in Queens, Westchester, or northern New Jersey, you may be looking at several hundred trees across multiple buildings. Either way, the inventory becomes the master document that drives everything else: the maintenance budget, the inspection schedule, the contractor scope of work, and the record that demonstrates the board is exercising reasonable care.
A good inventory is delivered as both a written report and a digital database (often a shared spreadsheet or a GIS-based platform) so it can be updated over time rather than recreated from scratch every few years. Tags on the trees themselves, keyed to the inventory, mean that any future arborist, contractor, or board member can identify a specific tree without ambiguity. When a resident emails about "the big tree by the side door," you can pull up Tree #47 and see its full history.
ANSI A300 and the standard of care
The American National Standards Institute publishes the A300 series, which sets the industry standard for tree care practices, and ISA Best Management Practices for Tree Risk Assessment, which sets the standard for how risk is evaluated. These aren't laws, however, they're the professional baseline that courts and insurance carriers look to when determining whether a property owner acted reasonably. Hiring an arborist who works to these standards, and ensuring it's named in the report, matters.
Tree risk assessment under this framework comes in three levels. Level 1 is a limited visual assessment, usually a walk-by or drive-by of a large population to flag obvious problems. Level 2 is the basic assessment most properties should be getting on a regular cycle: a 360-degree ground-level inspection of each tree, evaluating crown, trunk, root flare, and site conditions, and assigning a formal risk rating. Level 3 is advanced assessment. The use of a resistograph testing, air spading, aerial inspection, sonic tomographyreserved for specific trees where a Level 2 raised concerns that need deeper investigation. Your inventory and routine inspections are Level 2 work; Level 3 is targeted follow-up.
The risk rating itself follows a defined matrix combining likelihood of failure, likelihood of impacting a target, and consequences of impact, producing a rating of low, moderate, high, or extreme. This standardized language is exactly what you want in your records. "The tree looked bad" is not defensible. "Tree #47, a 26-inch DBH Norway maple with included bark at the primary union and a target zone including the children's play area, rated high risk in the May 2025 assessment, recommended for removal within 90 days" is.
How often, and what triggers an update
For most NYC metro co-ops and condos, the working cadence is:
A full tree inventory and Level 2 risk assessment every three to five years for stable, mature canopy. Properties with younger trees, recently disturbed soil, or aggressive growth may need it more often. Properties with very old, very large trees in high-target areas should be on the shorter end of that range.
Annual walk-through inspections in between full assessments. These are typically done in late winter or early spring when structure is visible without leaves, and they update the inventory rather than replacing it. Many boards pair this with a late-summer check during full leaf-out, when crown dieback and disease symptoms are most visible.
Post-storm inspections after any significant weather event: sustained winds over 50 mph, heavy wet snow, an ice event, or extended drought. These don't need to be exhaustive but should document that the property was walked and what was found.
Trigger-based reassessment whenever something material changes: construction or excavation within the root zones (concrete work, boiler replacements, gas line work, sidewalk vault repairs, and Local Law 11 sidewalk sheds all disturb roots), a tree failure anywhere on the property, a change in target use (new playground, new outdoor dining area, new bike storage), or new pest pressure in the area like spotted lanternfly or emerald ash borer.
What the board should keep on file
In addition to the inventory and assessment reports, the board's tree file should contain dated records of every inspection performed, every recommendation made by the arborist, and every action taken in response including the work orders, invoices, and before-and-after photos. If the board decided not to act on a recommendation, the minutes should reflect why, ideally with the arborist's input on the deferral. If a tree was rated moderate risk and pruning was scheduled for the next budget cycle, that scheduling is part of the record. The pattern you want, viewed from the outside two years later, is: the board inspected, the board was advised, the board acted reasonably and in a documented way.
Insurance carriers increasingly ask for this material at renewal. Some will discount premiums for properties with current arborist reports on file; some will non-renew properties with a claims history and no documented risk management program. Either way, the inventory pays for itself well before any incident occurs.
The practical starting point
If your board has never done this, the first step is straightforward: commission a baseline tree inventory and Level 2 risk assessment from a consulting arborist (look for ISA Certified Arborist credentials and, ideally, the TRAQ qualification — Tree Risk Assessment Qualified). Budget anywhere from $1,500 for a small Manhattan courtyard to $8,000–$15,000 for a larger garden complex. Build the resulting recommendations into the next operating or reserve budget, set an annual walk-through into the calendar, and you have a defensible program in place.
The trees on your property are appreciating assets ! Mature canopy demonstrably increases property values and is a real amenity for residents. I know I want to see trees from my windows when I live in a building. Managed well, they're an asset the board can be proud of. Managed by avoidance, they're a liability waiting for a windy night.