A BS5837 tree survey schedule records around 11 data points for every relevant tree — species, stem diameter, height, crown spread, crown clearance, age class, physiological condition, structural condition, estimated remaining contribution, retention category and root protection area — presented as one row per tree in a table.
The schedule is the technical core of any BS5837 tree survey. It looks like a dense spreadsheet, but every column is there for a reason. Here is what each data point means, why your planning authority's tree officer cares about it, and how the columns feed each other so an error in one ripples through the rest.
1. Tree reference and species
Each tree gets a unique reference number (T1, T2, or G1 for groups, H1 for hedges) that ties the schedule to the Tree Constraints Plan. Grouping matters: where a row of similar trees or a managed hedge adds nothing to assess individually, BS5837 lets the surveyor record it once as a group or hedge, while any notable specimen is pulled out and numbered on its own.
Species is recorded because it drives expected size, longevity, rooting behaviour and how the tree will respond to nearby construction — a fast-growing willow near drains raises different concerns from a slow, deep-rooted oak. Species identification is easier when trees are in leaf, though a BS5837 survey can still be done year-round.
2. Stem diameter (DBH)
The stem diameter is measured at 1.5 m above ground level — commonly written as DBH, diameter at breast height. This is the most consequential single figure in the whole survey, because the root protection area is calculated straight from it. Multi-stem trees are recorded with a combined notional diameter so the RPA still reflects the whole tree. Because every downstream constraint flows from this number, a sloppy DBH measurement is one of the quietest ways a report goes wrong.
3. Height
Overall tree height, usually estimated with a clinometer or measured. Height feeds shading assessments (how the tree affects future occupiers' light) and gives a sense of scale, but note that in BS5837 the operative constraint is the root protection area, not literal "falling distance" — that framing belongs to mortgage and hazard surveys, not development work.
4. Crown spread
The radius of the canopy is recorded in four directions (typically N, S, E, W). This lets the canopy be plotted accurately on the constraints plan and reveals any lopsided growth that might indicate an asymmetric root system — which in turn can justify re-plotting the RPA as a polygon rather than a circle. It also drives shading arcs and any judgement about crown clearance from proposed structures.
5. Crown clearance
The height of the lowest significant branches above ground. This informs whether the tree obstructs access, sightlines or proposed structures, and whether crown-lifting might be a reasonable management option rather than removal.
6. Age class
Recorded as young, semi-mature, early-mature, mature, over-mature or veteran. Age class shapes expected remaining life and, for veteran or ancient trees, triggers an enhanced root protection area (15 times stem diameter, or canopy plus 5 m, whichever is larger) and treatment as irreplaceable habitat under national policy. Getting age class right therefore isn't cosmetic — for an old tree it can multiply the protected area and change what can be built.
7. Physiological condition
The tree's health and vitality — good, fair or poor. Signs of stress, dieback, poor vigour or disease all count here and feed the retention category.
8. Structural condition
Separate from health: this is about the tree's physical integrity — decay, cavities, included bark, poor branch unions, lean or previous failures. A tree can be perfectly healthy but structurally compromised, which is why the two are graded independently. A vigorous tree with a major structural defect can still fall into a lower category or even U.
9. Estimated remaining contribution (RUL)
Often called remaining useful life, this is the arboriculturist's judgement of how many more years the tree will make a worthwhile contribution. It directly underpins the BS5837 category below — the two are read together, and an inflated RUL is one of the fastest ways to have a category challenged.
10. BS5837 retention category
Every tree is graded into one category, with a subcategory (1 = arboricultural, 2 = landscape, 3 = cultural/conservation value):
| Category | Meaning | Estimated remaining contribution |
|---|---|---|
| U | Unsuitable for retention (dead, dying, dangerous, badly defective) | Under ~10 years |
| A | High quality | 40 years or more |
| B | Moderate quality | 20 years or more |
| C | Low quality / young stems | 10 years or more |
The subcategory carries real weight. An A1 oak valued arboriculturally, a B2 lime valued for its landscape screening, and a C3 tree valued mainly for a cultural or conservation reason each place a different kind of constraint on a scheme — the tree officer reads the letter and the number together.
An important trap: the correct code for a tree that should be removed is U (unsuitable for retention). Older 2005-edition guides sometimes say "Category R" — that wording is outdated and should not appear in a current schedule. If it does, treat the whole report with caution.
11. Root protection area (RPA)
The final column is the calculated RPA — the below-ground area that must be safeguarded from digging, compaction and level change. The formula is:
RPA radius = 12 × stem diameter (measured at 1.5 m), capped at 707 m² (a 15 m radius) for very large trees.
So a tree with a 0.5 m stem diameter has an RPA radius of 6 m (about 113 m²); a 0.8 m stem gives a 9.6 m radius. Where rooting is provably asymmetric (constrained by a wall or road), the RPA can be re-plotted as a polygon of the same area rather than a circle. This column is where the survey stops being a description and becomes a constraint on your layout — which is why it appears last, drawing together diameter, age class and crown data from the rows above.
Worked example: one row, read in full
Take a single line: T7 — English oak (Quercus robur) — 620 mm DBH — 16 m high — crown spread 8/7/9/6 m — mature — physiological good, structural fair (minor deadwood) — RUL 40+ — B2 — RPA 7.44 m radius (~174 m²). Reading across, you learn that this is a healthy, structurally-sound-enough mature oak worth keeping mainly for its landscape value, and that anything you build must respect a roughly 7.4 m protection radius around it. If a proposed driveway or foundation clips that circle, the schedule has done its job: it has told the designer exactly where the conflict is before a spade goes in the ground. That is the whole purpose of the 11 data points working together.
What sits alongside the schedule
A good schedule or its accompanying arboricultural report also flags preliminary management recommendations and, critically, any Tree Preservation Order or conservation area status. These apply a separate, criminal-law-backed layer of protection on top of the planning assessment — so always run a TPO check independently.
The schedule alone does not assess your proposed layout. Once you have a design, this data feeds an Arboricultural Impact Assessment. To see how the schedule is produced in sequence, read our step-by-step guide to the BS5837 survey process, and for the wider picture start with the BS5837 tree survey for planning hub.
The columns are national — but how they're judged is local
BS5837 is a UK-wide British Standard, so these 11 data points appear on schedules everywhere. What varies is how a schedule is judged and what a council does with it. Whether an authority accepts a survey and constraints plan at validation or demands a full impact assessment first, how strictly its tree officer scrutinises category grading and RUL, and how densely the area is covered by TPOs and Conservation Areas are all local matters set by each planning authority's validation list. A generous "A" that sails through in one district may be downgraded in another.
Check your own council before relying on any schedule. PlanWatch tracks live tree-related planning activity per authority — start at the tree surveys hub and compare example areas such as Leeds, Lambeth or Nottingham to see how caseloads and local expectations differ. And remember the statutory framework differs in Scotland, Wales and Northern Ireland: the survey data points are the same, but the planning and protection rules around them are not, so verify locally if you are outside England.