Arboricultural method statement and tree protection plan

An arboricultural method statement says how the work will be done without damaging retained trees. A tree protection plan is the drawing that shows where the protection goes. Both are defined in BS 5837:2012, they are written after the impact assessment rather than alongside it, and councils routinely condition both.

They get muddled because a lot of consultants issue them as one document. That is fine in practice, provided both jobs are actually done.

What each document does under BS 5837:2012

The standard sets a sequence, and the sequence is the point.

A tree survey records every tree on and adjacent to the site, with species, dimensions, condition, estimated remaining contribution and a category. Categories run from U for trees that should be removed regardless of development, through A, B and C in descending order of quality.

A tree constraints plan takes the survey and draws it: canopy spread, root protection areas and shading, so the designer can see where the buildable area is.

The arboricultural impact assessment then tests the proposed layout against those constraints, identifies trees to be removed and the pressure on those retained.

The method statement follows. It describes how each item of work near a retained tree will be carried out: the sequence, the plant, the excavation method, the surfacing, the services, the supervision.

The tree protection plan is a scale drawing based on the finalised proposals, showing which trees go, which stay, and the protective measures with their positions and dimensions.

The order matters because a method statement written before the layout is fixed is describing work that may not happen.

The root protection area, and why it drives everything

The root protection area is calculated from stem diameter measured at 1.5 m above ground. For a single stem tree, the radius is 12 times the stem diameter, and the resulting area is capped at 707 m², which corresponds to a radius of about 15 m.

The circle it produces is then modified for local conditions: shifted where a wall, a road or a river has already restricted rooting, and reshaped rather than simply reduced, so that the total area stays the same where possible.

The construction exclusion zone is the area fenced off to protect the root protection area and the canopy. Barriers are specified in the standard, and the default for a construction site is a scaffold framework with weldmesh panels, braced and secured, with signage. A line of plastic mesh on stakes is not that.

Where any work has to happen inside the construction exclusion zone, the method statement has to justify it and specify how. That is the whole reason the document exists.

No-dig and special engineering solutions

Most conflicts between a layout and a retained tree are about a surface: a driveway, a footpath, a parking bay or a fire appliance route crossing the root protection area.

The usual answer is a no-dig construction. Existing levels are not excavated. A geotextile is laid over the ground, a three-dimensional cellular confinement system is placed on top and filled with a sharp angular granular material, and the surface is built up above existing ground level. Loads spread across the cells rather than compacting the soil beneath.

Three details decide whether it works.

The build-up raises finished levels, which has to be reconciled with thresholds, drainage falls and adjacent surfaces. Designers who add no-dig late find the levels no longer work.

Services cannot simply be trenched through. Where a service has to cross a root protection area, the method is trenchless, normally thrust boring or directional drilling at a depth that passes beneath the main rooting zone, with launch and reception pits outside the protected area.

And foundations near trees need designing for the tree as well as around it. On shrinkable clay that means deeper foundations, and the arboricultural and structural work have to be coordinated rather than done in sequence.

Special foundations such as piles and beams can allow a building closer to a tree than a strip footing would, at the cost of a considerably more involved method statement.

What the protection plan drawing must show

A tree protection plan that gets approved without comment shows the following.

• Every retained tree with its reference number matching the survey schedule
• Canopy spread and root protection area drawn to scale, with any modification of the circle shown and explained
• Trees to be removed, clearly distinguished
• The construction exclusion zone with the barrier line drawn, and the barrier specification annotated or referenced
• Ground protection where the exclusion zone has to be crossed or used, with its specification
• Site access, material storage areas, the site office and welfare, plainly outside the exclusion zones
• Positions of any no-dig construction, trenchless service crossings and special foundations

The last item on that list is the one auditors check first. A plan showing material storage inside a root protection area tells an officer the drawing was produced without the site logistics being thought about, and the same logistics belong in the Construction Management Plan.

Arboricultural supervision and site monitoring

Protection fails on site, not on paper. The method statement should therefore include a monitoring schedule that names the stages requiring an arboriculturist to attend.

Typical hold points are: barrier installation before any plant or material arrives, any excavation within a root protection area, no-dig construction installation, service crossings, and the removal of protection at the end of the works.

The schedule should say who reports, to whom and in what form. Councils increasingly condition the submission of site monitoring reports, and a schedule that already provides for them makes discharge straightforward.

An illustrative example. A four dwelling scheme retains a category B oak on the frontage. The method statement specifies a no-dig driveway across part of the root protection area, trenchless crossing for the water main, and barriers erected before any deliveries. On site, the groundworker arrives first, parks the excavator on the root protection area for a fortnight and stores blocks under the canopy. The soil compacts, the tree declines over the following two seasons, and the council's enforcement position rests on a condition requiring compliance with the approved statement. The document was right. The sequencing was not.

How councils condition both documents

Expect two conditions, sometimes three.

A condition, biting before work starts, requiring tree protection measures to be installed in accordance with the approved plan before any equipment, machinery or materials are brought onto site, and retained until works are complete.

A condition requiring the development to be carried out in accordance with the approved arboricultural method statement, with any variation agreed in writing beforehand.

And often a condition requiring submission of arboricultural monitoring reports at the stages set out in the method statement.

Where the documents were not submitted with the application, the council will impose a condition requiring them, and the discharge application then has to work with a layout already fixed. Producing them alongside the tree survey at application stage is faster and gives the designer room to move.

Councils expect a suitably qualified arboriculturist as author, and professional review is strongly advised. PlanScope drafts tree and Landscape Strategy documents structured to UK planning policy, with a "to be confirmed" flag wherever survey measurements are missing. This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.