Appointing an arboricultural clerk of works

An arboricultural clerk of works is the person who turns a tree protection plan into something that actually happens on site. Most tree conditions are discharged on paper before works start and then breached quietly in month three, when a subcontractor needs somewhere to stack blocks and the only flat ground is inside the barrier. Appointing a supervisor with defined visit triggers and a written route to stop work is how authorities have responded, and on constrained sites the condition now often names the role rather than simply requiring an arboricultural method statement.

It is a small appointment with an outsized effect, and it costs far less than the remedial planting that follows a root plate being driven over.

What the role covers on site

The supervisor works to the approved arboricultural method statement and tree protection plan, and their job is verification rather than design. In practice that means confirming that the protective barriers are erected in the right positions before anything else happens, attending the operations that take place within or adjacent to a root protection area, and recording what was found.

The role is distinct from the consultant who wrote the impact assessment, though it is often the same firm. The assessment author decides what protection is needed. The supervisor confirms it is in place and stays in place.

Three things sit outside the role and are worth stating in the appointment. The supervisor does not instruct the contractor on construction method, does not vary the approved statement without the authority's agreement, and does not carry the duty holder's responsibilities under health and safety law.

Frequency and the triggers for a visit

A fixed monthly visit is the usual default and it is not enough on its own. What works is a schedule combining routine visits with named hold points.

The hold points worth writing in:

• Before any works start, to verify barrier positions against the tree protection plan.
• Before and during any excavation within a root protection area.
• During installation of no-dig surfacing or cellular confinement systems.
• During service trenching, including any thrust boring within the protected area.
• During demolition or crane operations close to a canopy.
• Before any barrier is moved, shortened or removed.
• At completion, before the protection is taken down for the final time.

A supervisor who visits monthly and is not told about the trench dug on a Tuesday afternoon cannot do the job. The reporting obligation runs both ways, and the appointment should say so.

The detailed protection measures themselves, and how they survive a live programme, are covered in retaining a tree through a construction programme.

Authority to stop work, and how it is conferred

This is the part that gets skipped and the part that matters most. A planning condition does not give an arboriculturist authority over a construction site. Authority comes from the contract.

Two arrangements work. Either the appointment is made by the client under a consultancy agreement that names the supervisor in the contract particulars, with a clause allowing them to instruct the contract administrator to issue a stop instruction. Or the supervisor is appointed by the principal contractor with a written internal escalation to the site manager.

The second is faster on site and carries an obvious tension, because the supervisor's fee comes from the party they may need to stop. Where the trees are of real value, the client appointment is the one to press for.

Either way, write down what happens when a non-conformance is found: who is told, within what time, who decides, and what the supervisor does if nothing changes. The last step is usually to notify the local planning authority, and saying so in advance tends to mean it is never needed.

Records, photographs and reporting

The record is the deliverable. Each visit should produce a short report with the date and time, who was present, the weather and ground conditions, the works observed, the condition of each protective barrier, any non-conformance with the action agreed and a deadline, and dated photographs.

Photographs from fixed positions are worth the small effort of setting them up. The same view each month shows barrier movement, ground level changes and storage creep in a way that words do not.

Keep the reports in a single numbered series. When the authority asks for evidence to discharge the condition, a sequence of dated reports with photographs is accepted without argument, while a single closing letter usually is not.

Where crown work has been carried out during the build, the specification and the record of what was actually done should match, and the discipline for that is set out in pruning specifications and writing them properly.

Working with the main contractor

The relationship succeeds or fails in the first week. Get the supervisor into the site induction, and get a short toolbox talk delivered to every trade explaining what the barriers are, why they are there and who to call before anything crosses them.

And signage helps more than it should. A laminated notice on the barrier saying what it protects, with the site manager's number, stops a surprising amount of casual encroachment.

What causes most breaches is not defiance. It is a subcontractor arriving on a wet Monday needing hard standing, finding the only firm ground inside the barrier, and having nobody to ask. Solve that by designating an alternative storage area on the layout at the outset, and the problem largely disappears.

Cost and how it is programmed

Price it as a schedule rather than a lump sum: a fixed number of routine visits, a rate per additional visit triggered by a hold point, and a fee for the closing report. That structure lets the programme flex without a variation every time a date moves.

For a single plot with one retained tree, the appointment is a handful of visits. For a multi-phase site with a mature tree belt, it is a standing commitment across the whole build. Either way it sits in the preliminaries, and it should appear in the construction programme so that hold points are visible to everyone rather than remembered by one person.

Where a construction management plan is required, name the supervisor and the hold points in it. That single step converts an intention into a scheduled obligation.

The evidence an authority accepts

Councils discharging a tree protection condition generally want the same package: the approved method statement and protection plan, the numbered visit reports with photographs, a record of any non-conformance and how it was resolved, confirmation that protection stayed in place until completion, and a closing statement from the supervisor.

Send it before it is asked for. A condition left undischarged at the point of sale or handover creates an avoidable problem, and the supervisor who has been on site throughout can write the closing statement in an afternoon. Two years later, with a different consultant and no photographs, nobody can.

The underlying survey work that the whole process rests on sits in the arboricultural impact assessment, and councils usually expect a suitably qualified author for it, with professional review strongly advised.

Enter your postcode on PlanScope to see which tree and construction documents your site is likely to need.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified arboriculturist 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.