Independence and conflicts of interest in planning evidence

A conflict of interest in planning evidence is rarely a dramatic thing. It is the second instruction from a client you already act for on the adjoining site, or the appeal against a policy you helped write, or the review of a report your own colleague drafted last month. The damage comes from not declaring it, because the technical content then carries a discount that no amount of rigour recovers.

The rule that governs almost all of it is short. Evidence given to a decision maker is the author's own independent professional opinion, and where it is not, that has to be said on the face of the document.

Duties owed when giving evidence

At an inquiry, an expert's proof of evidence carries a declaration that the opinions expressed are the witness's true and professional opinions. That is not a formality. It is the basis on which the inspector gives the evidence weight.

The duty runs to the decision maker and it overrides the duty to the client who is paying. If the honest answer to a question in cross-examination damages your client's case, the honest answer is still the one you give.

Written representations and hearings carry the same obligation in substance, even where the formal declaration is lighter. A technical report submitted with an application is evidence too. An acoustician who adjusts a background sound level to make a rating level work has not produced a weaker report. They have produced one that cannot be relied on at all.

Where advocacy and expert evidence separate

These are different roles with different duties and the distinction gets blurred constantly in planning, because planning consultants routinely do both.

An advocate presents the client's case as persuasively as the facts allow. An expert gives an independent opinion and must say where the evidence cuts against the client. RICS guidance for surveyors acting as expert witnesses is explicit that the duty to the tribunal overrides the duty to the client, and it restricts acting as both advocate and expert in the same proceedings.

In practice the split shows up in the documents. A planning statement submitted with an application is advocacy, and nobody pretends otherwise. A daylight assessment appended to it is expert evidence and has to read like it, with the failures reported alongside the passes.

Problems arise when one person writes both and lets the register of the first bleed into the second. Keep them physically separate. Different documents, different authorship, different tone.

Common conflicts in planning work

The recurring ones are predictable enough to check for at the point of instruction.

• Acting for an applicant on a site while advising the same authority on plan-making or on a policy that bears on the application.
• Two clients competing for the same allocation, the same retail catchment or the same housing land supply argument.
• A former officer of the authority advising on a case they handled or influenced while employed there.
• A personal or family interest in land affected by the proposal, including land whose value moves with the outcome.
• A fee arrangement contingent on the outcome, which is generally incompatible with giving expert evidence.
• Reviewing or signing off a report produced by your own firm or by a colleague working to the same fee earner.
• A supplier relationship, for example recommending mitigation that your own business would install.

The last two catch people who would never dream of hiding the first five. Peer review inside a firm is useful quality control and it is not independent review, and saying so costs nothing.

Disclosing a conflict properly

Disclosure has three parts and most people do only the first.

State the facts of the relationship, plainly and in full, at the earliest point. State what has been done about it, whether that is declining the instruction, putting an information barrier in place, or obtaining informed consent from both clients. Then record it in the document itself, in the author's declaration, so that the reader sees it without having to ask.

Timing matters more than wording. A conflict disclosed at instruction is a managed risk. The same conflict disclosed in cross-examination is a credibility problem for every other paragraph of the proof.

Informed consent means the client understood what they were consenting to. A line in the engagement letter saying the firm may act for others is not consent to act for a direct competitor on the same appeal.

Some conflicts cannot be consented away. Where two clients' interests are directly opposed on the same question, an information barrier does not fix it and the firm should decline one instruction.

Independent review appointments

Independent review is a growing part of planning work, partly because more technical content is drafted quickly and needs a qualified eye before it goes in.

An independent reviewer is not the author's editor. They take responsibility for the content within their competence, which means they have to be free to change conclusions, to ask for further survey work, and to decline to sign. A review appointment that carries an expectation of approval is not a review.

Three conditions make a review appointment defensible. The reviewer is independent of the author and of the applicant. The reviewer holds the relevant competence, meaning the licence, chartered status or membership the discipline requires. And the reviewer's scope is written down, so that what was checked and what was not is on the record.

PlanScope's professional directory exists as the route to reviewers who can review and sign off AI-drafted reports, with a declaration at sign-off. For report types where a licensed or competent professional is legally required, including ecology work under the Conservation of Habitats and Species Regulations 2017, environmental statements under the EIA Regulations 2017 and fire statements under the Building Safety Act 2022 framework, the draft is a starting point for that professional rather than something they tidy up. Where an appointment is novated later in the project, the independence position changes again, and novating a consultant appointment to the contractor covers that ground.

Institutional codes of conduct

Each institute says a version of the same thing and the detail differs enough to matter.

The RTPI Code of Professional Conduct requires members to act with competence, honesty and integrity, and to disclose conflicts. RICS operates a conflicts of interest professional statement alongside its expert witness guidance, and both are mandatory for members. CIEEM, CIfA, the Institute of Acoustics, CIHT and the Institution of Structural Engineers each carry equivalent obligations for their disciplines.

Two practical points follow. Check the code of the institute whose competence you are relying on for the specific document, not the one you happen to belong to. And where a report is signed by a firm rather than a person, the named individual behind the signature still carries the personal obligation. Competence questions for specific disciplines are covered in who can prepare an overheating assessment to TM59.

Consequences of getting it wrong

The immediate consequence is weight. An inspector who finds that evidence was not independent discounts it, and the discount usually extends to the witness's other evidence.

Then costs. Unreasonable behaviour in an appeal can lead to an award of costs against a party, and advancing evidence that turns out to be partisan or unsupported is a recognised route to one.

Then the institute. Disciplinary processes are slower and more consequential than either of the above, and they operate on the individual rather than the firm.

And then the client, who has lost the appeal and is looking at the fee note. A conflict properly declared at week one costs an awkward phone call. The same conflict found at the inquiry costs the case. Where you are unsure whether something needs declaring, that uncertainty is itself the answer: put it in writing, and let the client and the decision maker judge it.

This is general guidance, not legal advice, so check your own institute's code and take advice on any specific conflict before acting.

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