A straightforward BS5837 tree survey typically takes around one to two weeks from instruction to report. The on-site visit itself is often just a few hours to half a day — most of the elapsed time is booking the visit and writing up the survey schedule, plan and report.
"How long does a tree survey take?" has two answers that get confused constantly: how long the surveyor actually spends on your trees, and how long before the finished report lands in your inbox. They are very different numbers, and it is the second one that matters for your planning programme.
The two-clock model
Think of it as two clocks running back to back:
- The field clock — the physical survey. On a small domestic site this is a few hours to half a day. The arboriculturist records every relevant tree: species, height, stem diameter, crown spread, age class, condition and a BS5837 category.
- The desk clock — turning field notes into deliverables. This is where the elapsed days go: building the schedule, calculating root protection areas, drafting the constraints plan and writing the report.
Add the scheduling gap before the visit and the two clocks together give the familiar one-to-two-week figure for a simple site.
The typical timeline
For a small domestic site with a handful of trees, a realistic breakdown looks like this:
| Stage | Typical duration |
|---|---|
| Instruction to booked site visit | A few days to ~1 week (surveyor availability) |
| The site visit itself | A few hours to half a day |
| Desk write-up (schedule, constraints plan, report) | A few days to ~1 week |
| Total, instruction to report | ~1–2 weeks |
Larger, more complex or heavily treed sites naturally take longer — a big development site can need a full day or several visits on the ground, and a proportionally longer write-up. These are market and practice ranges, not fixed guarantees, so always confirm turnaround when you instruct. If you want to understand what happens during each stage, see our step-by-step guide to the BS5837 tree survey process.
Two worked examples
Small householder job — a rear extension, three trees. You instruct on a Monday. The consultant is free the following week and surveys on the Wednesday — two hours on site for three trees and a neighbour's boundary tree. Over the next few days they build the survey schedule, calculate the root protection areas, draft the constraints plan and write up the impact assessment of your extension. Report in hand about ten days after instruction. This is the textbook one-to-two-week case, and it maps onto a typical tree survey for a home extension.
Larger site — a backland plot with forty trees. Here the field clock alone is a full day, sometimes two if access is awkward. Forty schedule rows, forty RPA calculations and a much larger constraints plan push the desk clock to a couple of weeks. If the layout is still moving, the impact assessment gets revisited each time the design changes. Three to four weeks, sometimes more, is realistic — and that is before any ecology is triggered.
Why the write-up takes as long as it does
The site visit is only the data-gathering half. Back at the desk, the arboriculturist has to turn field notes into a defined survey schedule — one row per tree with species, stem diameter, condition, BS5837 category and a calculated root protection area for each — then plot it all onto a scaled Tree Constraints Plan and write the report. On a live scheme, an Arboricultural Impact Assessment assessing your actual layout adds further time, and any method statement for works near roots is more again.
What delays a tree survey
Several things can stretch the timeline beyond the typical fortnight:
- Surveyor availability. Good consultants get booked up, especially in spring and summer. Instruct early.
- Site access. Locked gates, dense undergrowth, or trees behind neighbouring boundaries can force a return visit.
- Tree numbers and complexity. More trees, veteran trees, or awkward asymmetric root protection areas all add survey and drafting time.
- A required revisit. If conditions or access were poor first time, a second visit resets the clock.
- Ecology surveys triggered alongside. This is the big one. A BS5837 survey can be done year-round, but if bats, nesting birds or other protected species are in scope, those surveys have tight seasonal windows and can dominate — sometimes delaying an application by months. If your site might trigger ecology work, flag it at the very start.
Season doesn't stop the tree survey
Unlike ecology work, the BS5837 assessment itself does not depend on trees being in leaf, so you can commission one in winter. Species identification and some condition indicators are easier in leaf, but a winter survey is perfectly valid — a genuinely useful way to keep a project moving through the colder months while ecology windows are closed.
Local timelines matter too — check your council
The survey turnaround is only part of your programme. What happens after you submit is set locally, and it varies. Your local planning authority's validation team decides whether your application is complete; if the survey or impact assessment is missing where trees are affected, the application can be returned unregistered, adding weeks before you have even started. And where a permission carries a pre-commencement tree condition, the authority typically has around 8 weeks to decide an application to discharge that condition — time you must build in before any work can lawfully begin. How quickly a tree officer responds, and how much detail they demand at validation, differs from council to council.
So plan around your authority, not a national average. Start at the tree-surveys hub and check example authorities such as Manchester, Bristol or Leeds, and see which LPAs require a tree survey. PlanWatch tracks live tree-related planning activity per council, so you can gauge how busy and how demanding your authority is on trees before you commit to a timetable. Note too that the England-centric validation position above differs in Scotland, Wales and Northern Ireland, even though the BS5837 survey method is UK-wide.
Plan the survey around your application
Because the survey and Impact Assessment usually have to be submitted with your planning application — and because an authority may refuse to validate an application that omits them — build the one-to-two-week turnaround (plus any ecology windows and post-permission discharge time) into your programme from the outset. For the full list of documents your authority expects, see our guide to the tree survey for planning, and to budget the work read how much a tree survey costs.