Disclosure of draft technical reports in an appeal

There is no general duty of disclosure in a planning appeal. You are not in civil litigation, there is no standard disclosure stage, and nobody can require you to hand over every superseded draft on your file. What you do have is a duty not to mislead, a Planning Inspectorate expectation that you put forward the full particulars of your case, and a third party's right to request what you sent the council under the environmental information regulations. Draft report disclosure in an appeal is governed by that combination rather than by any single rule.

The practical consequence is counterintuitive. The documents most likely to surface are not the ones an opponent demands from you. They are the ones you emailed to the case officer eighteen months ago.

What has to be disclosed and when

Appeals under section 78 of the Town and Country Planning Act 1990 run on a documents timetable set by the procedure. Written representations, hearings and inquiries each have their own rules, but the structure is similar: a statement of case, then supporting evidence, then in an inquiry proofs of evidence and appendices, all by stated deadlines.

What the Inspectorate expects is that your statement sets out the full particulars of the case you intend to put. Evidence introduced late can be refused, and an inspector can decline to take account of material produced at a hearing that should have been in the statement. That is a rule about completeness of your own case, not about producing your opponent's.

Separately, every document you submitted to the local planning authority during the application sits on the authority's file. It is almost certainly environmental information under the Environmental Information Regulations 2004, and the authority has to disclose it on request subject to the exceptions in those regulations. Objectors use this routinely. An earlier version of a noise survey, sent informally to an officer and then superseded, is obtainable by anyone who asks the council for it.

Drafts, privilege and the limits of it

Legal advice privilege protects communications between you and your lawyers for the purpose of giving or receiving legal advice. That is real and it holds.

Litigation privilege, which protects documents prepared for the dominant purpose of adversarial litigation, is a different and much less certain proposition in planning. Appeals to the Inspectorate are administrative determinations rather than litigation in the ordinary sense, and the application of litigation privilege to them should not be assumed. If the question matters to a document on your file, take specialist legal advice on it rather than relying on a general sense that drafts are privileged. They are usually not.

What protects an ordinary technical draft is something simpler: nobody has a right to ask for it, and it was never sent to the council. A draft that lived between consultant and client, was superseded, and never left the project team, is not disclosable by any route.

A draft that was sent to the authority is a different matter, and so is a draft that is referred to in a document you are relying on. Cite an earlier survey in your proof of evidence and you have put it in issue, and an inspector can ask for it.

Adverse findings and the duty not to mislead

This is where professional obligations do real work.

The RTPI Code of Professional Conduct requires members not to make statements that are misleading, and the RICS Rules of Conduct impose comparable duties. Anyone giving expert evidence at an inquiry is expected to give their own independent opinion and to refer to the material facts that detract from it. Those duties bite whether or not any disclosure rule applies.

So the position on a survey with an inconvenient result is not "can I withhold it" but "can I present my case honestly without it". Often the answer is no. A transport assessment that reports a junction capacity result without mentioning the earlier count that showed worse performance is not a complete account, and an inspector who learns about the earlier count from an objector will treat everything else in that evidence with suspicion.

The better approach is almost always to put the adverse material in and explain it. Surveys get superseded for good reasons: the wrong period was counted, the methodology changed, the scheme changed. Say that. An explained inconsistency is a technical matter. A discovered omission is a credibility matter, and credibility is the one thing you cannot recover mid-inquiry.

Where two reports in your own submission disagree, resolve it before you get to appeal. The same applies when the authority's own adviser takes a different view, and the approach set out in what to do when the council's expert disagrees with your consultant belongs at application stage rather than at the inquiry.

Requests from the authority

Authorities do ask. The common forms are a request for the earlier version of a report referred to in a later one, a request for the raw survey data behind a model, and a request for the ecologist's field notes.

Raw data requests are usually reasonable and usually worth meeting. A noise consultant's measurement records, a transport consultant's turning counts, an ecologist's survey forms: these are the evidence behind the conclusion, and refusing them invites the inspector to give the conclusion less weight. Supply them as an appendix.

Requests for drafts are different and can be declined, politely and with a reason: that the document is superseded, that the final version is before the inspector, and that the conclusions in the final version are the ones being relied on. Do that in writing so the record shows a considered position rather than evasion.

What you should not do is deny that a draft exists. If an objector has already obtained it from the council under an environmental information request, which happens, the denial is the problem rather than the draft.

How inspectors react to withheld material

Inspectors have no power to order disclosure in the way a court does, but they have the power that matters: they decide what weight to give evidence.

A pattern that recurs in appeal decisions is an inspector noting that a conclusion was not supported by the underlying data, or that a point put to a witness was not satisfactorily answered, and attaching reduced weight to that evidence as a result. Inspectors also have the power to require the attendance of witnesses and the production of documents at an inquiry under the relevant procedure rules.

Appeal decisions are indicative of how inspectors have approached these issues rather than binding precedent, but the pattern is consistent enough to plan around. Evidence that can be audited is given weight. Evidence that cannot is discounted.

There is also a costs dimension. Unreasonable behaviour in an appeal can lead to an award of costs, and obstructing a reasonable request for the data behind your own evidence is the kind of conduct that gets described that way.

Managing drafts during a project

Document discipline costs less than argument. Six habits cover most of the risk:

1. Agree at the outset which documents go to the authority and which stay internal, and route everything through one person.
2. Do not send working drafts to the case officer. Send a version marked as issued, with a revision and a date, or send a note instead.
3. Where you need an officer's view on an emerging finding, put the question in a letter rather than attaching the half-finished report.
4. Keep superseded versions, with a short note of why each was superseded. Destroying them is worse than holding them.
5. Maintain a document register for the project: every version, its date, who it went to and whether it is current.
6. When a finding changes materially, write a one-page explanation at the time. Reconstructing the reason two years later is unconvincing even when it is true.

The second habit is the one that saves the most trouble. Most problematic drafts reach the authority because a consultant wanted to be helpful.

Practical document discipline before an appeal

When an appeal is decided on, do a file review before the statement of case is drafted. List every version of every technical document, mark which went to the authority, and identify where the conclusions changed between versions.

Then decide, deliberately, what the appeal case relies on. Where a change of conclusion has to be explained, explain it in the statement rather than waiting to be asked at the hearing. Where a report has a named author whose competence may be questioned, make sure the report carries a named author and a date and that the author is available. Where the authorship has moved during the project, the record built up in changing consultant mid-application without losing evidence is what keeps the chain intact.

Finally, assume the objector has a copy of everything the council holds. Plan the case on that basis and the disclosure question mostly disappears.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. Where privilege or professional conduct is in issue, take specialist legal advice. If you need a qualified reviewer to check a technical report before it goes into an appeal, the professional directory is the route to a review and sign-off.

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