Guide
BS5837 tree survey for planning explained: cost, categories, RPA
Updated
If a planning officer or your architect has asked for a "tree survey to BS5837", this is what they mean, what it costs, and which extra documents (AIA, method statement) your application might also need.
What BS5837 is
BS 5837:2012, Trees in relation to design, demolition and construction, is the British Standard councils expect tree information to follow when development is proposed near trees. The survey is carried out by an arboriculturist, who records every relevant tree (species, dimensions, condition, estimated remaining contribution) and grades each one into a category. It is a design input, done properly it happens before the layout is fixed, not after.
The categories, in plain terms
- Category U
- Trees that cannot realistically be retained for more than about 10 years: dead, dying or dangerous. Removal is usually uncontroversial.
- Category A
- High quality trees with 40+ years' remaining contribution. Designing around these is strongly expected; losing one weakens an application.
- Category B
- Moderate quality, 20+ years. The middle ground where most negotiation happens.
- Category C
- Low quality, 10+ years. Retention carries less weight, but C-grade trees are not automatically removable.
Root protection areas
For each retained tree the survey calculates a root protection area (RPA), the standard's default is an area based on 12 times the stem diameter, plotted on a tree constraints plan. Buildings, drives, drainage and levels changes inside an RPA are what turn a simple application into a contested one, which is why the survey needs to exist before the site layout does.
What it costs and what else you might need
| Deliverable | Typical cost |
|---|---|
| BS5837 tree survey + tree constraints plan, small site (single plot, a handful of trees) | £250–£500 |
| Arboricultural impact assessment (AIA) on top of the survey | £200–£500 extra |
| Arboricultural method statement + tree protection plan for conditions | £200–£500 extra |
| Larger or heavily treed sites, all documents | £1,000+ |
- Ask the council's validation checklist, or your architect, exactly which documents the application needs; buying them together is usually cheaper than sequentially.
- Planning authorities commonly expect the survey data to be recent, around two years is a widely applied rule of thumb, so don't commission it years before applying.
- If protected trees are involved, read the TPO guide before any work, including site clearance.