Confidential viability appraisals and the publication question

The viability assessment confidential publication argument is one most applicants lose, and losing it late is worse than not running it. Planning Practice Guidance on viability says an assessment should be prepared on the basis that it will be made publicly available other than in exceptional circumstances, and that even in those circumstances an executive summary should be published. Authorities treat that as the price of having the assessment considered at all.

So the useful question is not whether the appraisal can be kept private. It is what the published version looks like, and how to write one document rather than two.

The default position on publication

Publication is the starting point, and it follows from what a viability assessment is for. The assessment is being used to justify providing less than the policy requirement, usually on affordable housing, and the people who lose out are the people on the housing register. A reduction justified by figures nobody can see is a reduction nobody can challenge.

That is why the guidance pairs transparency with proportionality, and why the national approach expects a standardised set of inputs. Where a scheme complies with an up-to-date plan, no viability assessment should be needed at all, and the plan should set out the circumstances in which one will be entertained. Check that wording in the local plan before commissioning anything, because some authorities have been explicit about it.

Why the guidance pushes towards transparency

Three reasons, and they shape how officers read the document.

The first is accountability. Members have to explain in public why a scheme delivering 12 per cent affordable housing was approved against a policy seeking 35 per cent, and they cannot do that from a confidential annex.

The second is testability. A benchmark land value or a profit assumption only means something if someone can compare it with evidence. The professional statement published by the Royal Institution of Chartered Surveyors on assessing viability under national policy puts objectivity and independence at the centre of the exercise, and objectivity that cannot be checked is an assertion.

The third is practical. Authorities commission an independent review of appraisals routinely, and the reviewer's report becomes part of the case file. Keeping your appraisal confidential while the review of it is published is not a stable position.

Commercial confidentiality claims and their limits

The claims that get anywhere are narrow and specific. A land price agreed but not yet exchanged. A tenant's rent under a confidential agreement for lease. A contractor's build-up that is subject to a tender confidentiality undertaking. Personal data about individuals.

The claims that do not work are the ones about the substance:

Asserting that the whole appraisal is commercially sensitive invites a short officer response and a delay. Identifying three figures and explaining precisely why each would prejudice a live negotiation is a conversation an authority can have.

Redaction, and what can properly be withheld

Redaction is a tool for a narrow set of entries, not a way of publishing a document with its conclusions intact and its reasoning removed.

Structure the appraisal so redaction is possible without destroying it. Put sensitive material in a clearly identified appendix. Keep the assumptions in the body of the report, expressed as rates and allowances with their sources, rather than embedded in a spreadsheet extract. Use published cost data with a citation for the build cost, since a published source is harder to argue about and impossible to keep secret.

Then produce the executive summary deliberately. It should set out the policy requirement, the scheme, the inputs at a level that lets a reader follow the logic, the result, and the offer being made. A summary that says only that the scheme cannot support policy compliant affordable housing is not a summary of anything.

Getting the format the appraisal arrives in right at the outset makes all of this easier, because the redaction problem is mostly a structuring problem.

Requests for environmental information

Where an appraisal relates to development that affects the environment, it is likely to be environmental information, and the Environmental Information Regulations 2004 apply rather than the general freedom of information regime. That distinction matters.

The commercial confidentiality exception in the environmental regime requires confidentiality to be provided by law to protect a legitimate economic interest, and it is subject to a public interest test with an express presumption in favour of disclosure. The equivalent exemption in section 43 of the Freedom of Information Act 2000 is also qualified by a public interest test, but without that presumption.

The Information Commissioner and the First-tier Tribunal have ordered disclosure of development appraisals where the public interest in understanding a reduced affordable housing contribution outweighed the applicant's commercial interest. The general pattern in those decisions is that the sensitivity of figures decays with time, and that the public interest is strongest while the decision is live.

Which leads to a practical point. Information withheld at application stage is often disclosed a year later, by which time the commercial reason for withholding it has gone and the only lasting effect is the impression that something was being hidden.

Appeals, committees and the natural justice problem

At committee, the route to a private discussion is the exempt information categories in Schedule 12A to the Local Government Act 1972, which include information relating to the financial or business affairs of a particular person. The committee resolves to exclude the public for that item.

That mechanism has limits. Members still have to give reasons in open session, and a decision that cannot be explained without the confidential material is a decision that will be criticised. Objectors and local members increasingly ask for the viability item to be taken in public, and some authorities have stopped using the exemption for viability at all.

At appeal the position is firmer. Appeal documents are public, and an inspector cannot base a decision on evidence that other parties have had no chance to test. An appraisal submitted on a confidential basis tends to be given less weight rather than kept private, which is the opposite of the intended effect.

Writing an appraisal that expects to be published

1. Write for an intelligent reader who is not a surveyor, with the method stated and the inputs tabulated.
2. Name the source of every input, and prefer published sources for costs and values.
3. Keep legal advice, board papers and internal correspondence out of the document entirely.
4. State the policy requirement and the shortfall plainly at the front.
5. Deal with the standard inputs the authority will ask about, including space standards and accessible housing requirements as inputs, rather than leaving them to be raised by the reviewer.
6. Isolate the few sensitive items in a short appendix, with a reasoned case for withholding each one.
7. Draft the executive summary as a document in its own right.
8. Offer a review mechanism, early or late stage, where the appraisal is marginal, since that is often what unlocks an agreement.

A Viability Assessment is a document councils expect from a suitably qualified author, and professional review before submission is strongly advised. A draft can set the structure, the policy framework, the list of inputs the guidance expects and the narrative around the result. The valuations, the benchmark land value judgement and the professional opinion have to come from a valuer who will put their name to them and defend them at committee.

One honest uncertainty: how much weight an authority gives to a viability case varies with the strength of its plan and the state of its housing land supply, and the same figures can produce different outcomes in neighbouring districts.

Enter your postcode on PlanScope to see which reports and statements your scheme is likely to need alongside the appraisal.

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.