A BS5837 tree survey follows a clear sequence: a desk study, a site visit to record every relevant tree, compilation of the tree survey schedule, production of a scaled Tree Constraints Plan, and a written report — ideally completed before the site layout is designed so the trees shape the scheme. Once a layout exists the survey feeds an Arboricultural Impact Assessment, and after permission a method statement and protection plan are usually discharged as conditions.
If your planning application affects trees, BS5837:2012 is the framework your local planning authority (LPA) will expect you to follow. It is a British Standard containing recommendations, not a law — but authorities adopt it in their validation lists and impose it through planning conditions, so in practice it is unavoidable. Here is what actually happens, stage by stage.
Stage 1 — Instruction and desk study
Before anyone visits, a good arboriculturist does a short desk study. They confirm the site boundary, check whether any trees carry a Tree Preservation Order or sit within a conservation area, and identify neighbouring trees whose roots may reach onto your land. This matters because the survey must capture off-site trees whose root protection areas cross the boundary — not just trees you own.
Timing tip: instruct the survey before you commit to a layout. BS5837 is deliberately design-led. The whole point is that tree constraints shape where you can build, so a survey done after the design is fixed often forces expensive redesign — or a refusal.
Stage 2 — The site visit
The arboriculturist attends site and inspects every relevant tree individually. For each one they record a defined set of measurements and observations — species, stem diameter at 1.5 m above ground, height, crown spread in four directions (north, south, east and west), age class, and physiological and structural condition. This is a visual, ground-level assessment (formally a Preliminary Tree Assessment); it is not a climbing inspection or a decay-detection survey unless separately commissioned.
From the stem diameter they calculate each tree's root protection area (RPA) — a circle with a radius of 12 times the stem diameter, capped at 707 m² (a 15 m radius) for very large trees. Veteran and ancient trees get an enhanced area of 15 times the stem diameter, or the canopy edge plus 5 m, whichever is larger. A multi-stem tree uses a combined notional stem diameter. You do not need to be present; the surveyor just needs safe access to the base of each tree.
Worked example. A mature oak with a 0.5 m (500 mm) stem diameter gives an RPA radius of 12 × 0.5 = 6 m — a circle of roughly 113 m². If that oak stands in a neighbour's garden 4 m from your boundary, a chunk of its RPA lands on your plot, and any foundations, drains or driveway you propose within it become a live constraint the survey must address. Full detail on exactly what gets recorded is in our guide to the tree survey schedule data points.
Stage 3 — The tree survey schedule
Back at the desk, the field data becomes the tree survey schedule — a table with one row per tree. Crucially, each tree is assigned a BS5837 retention category:
| Category | Meaning | Estimated remaining contribution |
|---|---|---|
| U | Unsuitable for retention (dead, dying, dangerous or badly defective) | Under ~10 years |
| A | High quality, worth retaining | 40 years or more |
| B | Moderate quality, retention desirable | 20 years or more |
| C | Low quality, minor constraint | 10 years or more (or young stems under 150 mm) |
Each grade also carries a subcategory showing why the tree has value: 1 for mainly arboricultural qualities, 2 for mainly landscape value, 3 for mainly cultural or conservation value. So an "A1" is a high-quality tree valued arboriculturally, a "B2" a moderate tree valued for its landscape contribution. Note that the correct code for a tree that should go is U — not "Category R", which is outdated 2005-edition wording that still circulates online. If a report grades your trees as "R", that is a red flag about the consultant.
Stage 4 — The Tree Constraints Plan
The schedule data is then plotted onto a scaled drawing: the Tree Constraints Plan (TCP). It shows each tree's position, crown spread and RPA as a circle or polygon (the RPA can be reshaped into a polygon of the same area where rooting is provably asymmetric — for example against an existing wall). Read together, these overlays reveal the "developable envelope" — the parts of the site you can build on without conflicting with trees worth keeping. This is the drawing your architect should design around, not one they consult after the layout is fixed.
Stage 5 — The report, the impact assessment, and what comes next
Finally you get a written arboricultural report pulling the schedule, plan and commentary together. For a straightforward domestic site, the whole process — visit to report — typically takes around one to two weeks; larger or phased sites take longer. As a rough cost guide, a basic domestic survey runs around £295–£760, and a full planning package around £400–£1,500+. See our guide on how long a tree survey takes for what drives the timeline.
The survey and TCP are only the first half of the story. Once a layout exists, they feed into:
- an Arboricultural Impact Assessment (AIA) — which trees are lost, which are retained, and what construction conflicts arise. This is submitted with the application;
- a Tree Protection Plan (TPP) showing barrier fencing, ground protection and construction exclusion zones; and
- an Arboricultural Method Statement (AMS) — the detailed "how" of working near retained trees, usually imposed as a pre-commencement condition and approved in writing after permission but before any works start.
The mental model worth holding: the survey, TCP and AIA are the pre-permission "can we build this?" documents; the AMS, final TPP and any site supervision are the post-permission "prove you'll protect them" documents discharged as conditions. Starting site works — even demolition or clearance — before a pre-commencement tree condition is discharged can render the whole development unlawful.
What goes wrong
A handful of failure modes account for most tree-related delays:
- Missing documents at validation — the LPA won't even register the application if trees are affected and the survey or AIA is absent.
- Surveying after the design is fixed — RPAs discovered late force redesign of roads, foundations or drainage.
- Ignoring neighbouring trees whose RPAs cross the boundary.
- Unjustified RPA incursions — building or hard surfacing inside an RPA without a no-dig or engineered solution set out in the AMS.
- Optimistic categories a tree officer rejects, or failing to flag a TPO or conservation area tree as protected.
Where the survey fits: requirements are set locally
For most applications where trees are affected, the survey plus an AIA must be submitted with the application — without them, the authority may refuse to validate it at all. But exactly what your council demands, and how strictly its tree officer applies it, is set locally. Some authorities want a full AIA, TPP and preliminary AMS upfront; others accept a survey at validation and condition the rest. Councils differ in TPO density, conservation area coverage, and whether ancient or veteran trees raise the bar. The national validation baseline comes from government guidance, but the arboricultural specifics are a local overlay — so always check your own authority's validation list before you submit.
PlanWatch tracks live tree-related planning activity per council, so you can see how tree issues are being handled in your area. Compare requirements and recent applications across authorities such as Leeds, Manchester and Bristol, then check your own council from the tree surveys hub. To understand the full package your authority needs, start with our main guide to the BS5837 tree survey for planning, or read about the wider tree survey for planning requirements.
A note on nations: BS5837:2012 applies UK-wide as a British Standard, but the statutory framework around it (validation lists, TPO regulations) differs in Scotland, Wales and Northern Ireland. The process above is described for England.