How Often Should a Tree Condition Survey Be Done? (UK Guide)

Last winter I checked a mature lime over a busy school footway. Looked fine from the pavement, but a long lateral had too much end-weight and fresh brackets were showing at the buttress. We chose a light reduction, removed deadwood, and set a 12-month review—safer site, canopy kept, cost sensible. That’s the purpose of routine surveys: proportionate decisions, grounded in evidence.

Quick answer (rule of thumb)

• High-risk sites (schools, play areas, busy car parks, along highways): every 12 months—and sooner after extreme weather.
• Moderate-risk sites (typical residential gardens, workplaces): every 18 months.
• Low-risk sites (lightly used grounds, remote areas): every 2–3 years.
• Always add a reactive inspection after storms, construction, or if you notice new defects.

Why tree condition surveys matter

A tree condition survey (often called a tree health & safety survey) records condition, highlights defects, and sets clear, time-bound recommendations. Done regularly, it helps you manage risk, catch issues early (decay, weak unions, pests/disease), plan budgets sensibly, and show a reasonable duty of care to insurers and neighbours.

Recommended frequency (and what changes it)

Intervals depend on site use, target occupancy (what could be hit), species, age, known defects and wind exposure.

• High-risk (schools, busy parks, hospital/retail car parks, trees over highways/footways): 12 months. Consider 6–12 months for mature/defected trees.
• Moderate-risk (typical homes, small workplaces, communal gardens): 18–24 months. Shorten if there’s defect history or heavy public use.
• Low-risk (large private grounds with limited access): 2–3 years. Mature poplar/willow often need closer attention.
• Recently worked-on or defected trees: as recommended (e.g., 3–12 months) to monitor healing/decay progression.
• After severe weather or site changes: reactive inspection—storms, groundworks, new parking/play areas, subsidence signs.

Tip: Aim main inspections for late summer–autumn (full leaf = best vitality check) and use winter follow-ups if you need a clearer view of structure.

What happens during a tree survey inspection?

• Visual Tree Assessment (VTA): form, vitality, deadwood, cracks/cavities, fungal fruiting bodies, unions, root plate.
• Target & occupancy assessment: how likely impact is if a part fails.
• Measurements & mapping: species, height, DBH, crown spread, GPS/plan ref, tags if needed.
• Tools as needed: sounding hammer, probe, binoculars; advanced decay testing (e.g., resistograph) if indicated.
• Recommendations: risk-led, prioritised (e.g., “within 3 months”), with a re-inspection date.
• Deliverables: clear report, works schedule, plan or GIS export for asset management.

Signs you should bring a survey forward

Sudden lean or soil heave; root-plate movement; new cracks or lifting bark; rapidly enlarging cavities; persistent deadwood or significant dieback; fungal brackets at the base/major limbs; nearby construction (trenches, level changes, services); storm damage; repeated heavy pruning by unqualified contractors; subsidence symptoms (sticking doors, stepped cracks, seasonal movement in shrinkable clays).

How often… by client type

• Homeowners & landlords: usually every 18 months; annually for large, mature or defected trees over high-use areas. (18 months lets us see different seasons—some fungi are annual and only appear at certain times.)
• Schools & care settings: annual surveys, with interim checks after named storms.
• Commercial estates / housing associations: tiered regime—annual in high-use zones; 18–24 months elsewhere; ad-hoc post-storm inspections.
• Development sites: baseline pre-works, monitoring during construction, post-completion confirmation.
• High-amenity / veteran trees: tailored monitoring (often 12 months) plus detailed investigations where helpful.

Duty of care and the law (UK)

People in control of land have legal duties behind a sensible inspection regime:

• Occupiers’ Liability Act 1957 (s.2): common duty of care to lawful visitors. Trees are part of the premises. Legislation.gov.uk
• Occupiers’ Liability Act 1984: certain duties to non-visitors (e.g., trespassers) where a known danger exists. Legislation.gov.uk
• Health and Safety at Work etc. Act 1974 (s.3): protect non-employees from risks arising from your undertaking, including trees. Legislation.gov.uk
• Management of Health and Safety at Work Regulations 1999 (reg.3): require suitable and sufficient risk assessment. Legislation.gov.uk HSE

HSE guidance supports proportionate, risk-zoned inspections—not blanket, overly frequent checks. Record your intervals and review after storms or site changes. HSE qtra.co.uk
(Informational only, not legal advice.)

Tree condition survey cost (UK): what to expect

Costs vary with access, tree numbers, report format and any advanced testing:

• Small residential (up to ~10 trees): £300–£450+VAT
• Medium sites / communal grounds (~10–50 trees): £450–£900+VAT
• Larger estates / campuses (50–200+ trees): £900–£2,000++VAT
• Add-ons: decay testing, traffic management, climbing inspections, CAD/GIS plans

You’ll often save per-tree with grouped surveys (neighbours or estates). Ask for a scope that fits your risk profile—not one-size-fits-all.

How to set up a defensible inspection regime

1. Baseline survey to map trees and set priorities.
2. Risk zoning to identify high-use areas and sensitive targets.
3. Define intervals from the guidance above; add dates to your maintenance calendar.
4. Record-keeping: keep reports, photos and completion notes for works.
5. Trigger events: storms, construction or visible defects = reactive inspection.
6. Qualified surveyor: use an arboricultural consultant (e.g., Professional Tree Inspector qualified) with appropriate insurance.

FAQs

How often should a tree survey be done?
Most homes: every 18 months. Busy public/high-risk areas: annually, plus reactive checks after severe weather.

What affects frequency?
Site usage, targets, species, maturity, past defects, wind exposure, soil conditions and recent works.

What’s included?
Structured inspection with VTA, measurements, mapping, risk rating, recommendations and a re-inspection date.

How much does it cost?
From ~£300+VAT for small jobs, scaling with tree numbers and any specialist testing.

What is my legal “duty of care” for trees?
In the UK, your duty arises from the Occupiers’ Liability Acts 1957 & 1984 and, for employers/self-employed, HSWA 1974 s.3 plus the Management Regulations 1999. In practice, that means a reasonable, documented inspection regime proportionate to your site’s risks, with reactive checks after storms or changes. Legislation.gov.uk, Legislation.gov.uk, Legislation.gov.uk

Practical next steps

• Not had a survey in 2+ years? You’re due.
• Had a storm or near-miss? Book a reactive inspection now.
• Managing many trees? Ask for a zoned plan and GIS-ready output.