Open book viability and what can properly be redacted

Write every viability appraisal on the assumption that it will be published in full. National policy says viability assessments should reflect the recommended approach in planning guidance, including standardised inputs, and should be made publicly available. The Planning Practice Guidance goes further, stating that an assessment should be prepared on the basis that it will be made public other than in exceptional circumstances, and that even then an executive summary should be published. So open book viability confidentiality is a narrow argument about specific inputs, not a general right to keep the appraisal private.

That has changed how these documents are written. An appraisal drafted for a lender or an investment committee reads badly in a planning context, and it reads worse when a resident quotes it back at committee.

The policy expectation of transparency

The logic behind publication is straightforward. A viability case asks the council to accept less affordable housing or fewer contributions than policy requires, and a community cannot test that case without seeing the numbers.

The RICS professional statement on financial viability in planning sets the professional framework around that, requiring objectivity, a clear statement of instructions and transparency of inputs. A surveyor preparing or reviewing an appraisal is bound by it whichever side instructs them.

What transparency means in practice is that the standardised inputs have to be visible: gross development value with the schedule and values behind it, build costs with the source, professional fees, finance, developer return, the benchmark land value and how it was derived, and the policy costs being tested. An appraisal that publishes a conclusion and withholds the inputs does not satisfy the expectation, and a Viability Assessment written that way tends to be returned at validation.

What can properly be redacted

The grounds are narrower than applicants hope, and they are about specific items rather than whole documents.

Defensible candidates for redaction include a third party's tendered sum where that party is contractually entitled to confidentiality, the commercially sensitive terms of a funding agreement, personal data about individuals, and the identity of a prospective occupier where disclosure would prejudice a live transaction. Even then the redaction should be minimal, flagged, and accompanied by a reason.

What is not defensible: the land price paid, the developer's target return, the build cost rate, the benchmark land value, the affordable housing offer, or the appraisal output. Those are the inputs the policy expects to be tested.

The practical approach is to structure the document so the sensitive material sits in a discrete appendix that can be withheld without gutting the rest. Marking the whole appraisal as confidential achieves nothing except a slower validation.

Publication practice at application stage

Most councils upload the appraisal to the online planning register with the rest of the submission. Some publish a redacted version alongside an unredacted copy held for the reviewer. Some withhold until the officer's report, which is poor practice and attracts complaints.

Ask at pre-application what the council's practice is, and agree the redaction schedule in advance rather than arguing about it after the documents are live. Once a document is published it cannot be unpublished in any meaningful sense.

Where the appraisal supports a reduced affordable housing offer, the Affordable Housing Statement should state the offer plainly and cross-refer to the appraisal rather than burying the position in a footnote. Officers and objectors both read the statement first.

Independent review and the reviewer's role

Councils almost always instruct an independent reviewer, and the applicant almost always pays. The reviewer's report is usually published too, which means the exchange of positions becomes part of the public record.

Two consequences follow. First, write the appraisal expecting a professional to disagree with it in public, so take out any input you could not defend at an inquiry. Second, engage with the reviewer's questions in writing rather than through a meeting with no note, because an unanswered question in a published review report becomes the officer's reason for recommending refusal.

The reviewer is not the council's advocate. A good reviewer will accept inputs that are properly evidenced and reject those that are not, on either side of the argument, and the professional statement requires that independence.

Freedom of information requests

Even where something has been withheld, it can be requested. Most planning information is environmental information, so requests are usually handled under the Environmental Information Regulations 2004 rather than the Freedom of Information Act 2000.

That distinction matters. The regulations include an exception for the confidentiality of commercial or industrial information where that confidentiality is provided by law to protect a legitimate economic interest, but they apply a public interest test with an express presumption in favour of disclosure. The equivalent exemption for commercial interests under the 2000 Act works differently and requires a prejudice test.

The upshot for an applicant is simple enough. Material withheld at application stage is often disclosed on request months later, and by then the opportunity to explain it has gone. Better to publish it with your own commentary attached.

Managing commercially sensitive inputs

Several techniques reduce the exposure without weakening the case.

1. Use market evidence rather than actual contract sums where the market evidence supports the same figure. A published cost index and a quantity surveyor's build-up are less sensitive than a signed subcontract.
2. Obtain written consent from third parties whose figures you are relying on, at the point you ask for the quotation rather than afterwards.
3. Present commercially sensitive items as a range with the basis of each end stated, where a single figure would identify a counterparty.
4. Put the sensitive material in an appendix with its own numbering, so a redaction removes the appendix and nothing else.
5. Avoid naming individuals anywhere in the document.

None of these allow you to withhold the standardised inputs. They cut the collateral disclosure that comes with publishing them.

Preparing an appraisal for publication

Read the draft as a resident would. Internal language about squeezing the scheme, or about what the council can be persuaded to accept, does real damage even when the arithmetic is sound.

What a publication-ready appraisal contains: an executive summary written in plain terms, a statement of instructions and the basis of the valuation, a table of inputs with the source and date of each, the benchmark land value with the evidence behind it, a sensitivity analysis, a clear statement of what is being offered and what policy would require, and a redaction schedule listing anything withheld with the reason.

Where the outcome is contested, a review mechanism gives both sides a way out, and the drafting of those mechanisms is covered in affordable housing review mechanisms in section 106. A late stage review turns an argument about today's forecast into a calculation on actual figures, which is easier to publish and easier to defend.

If the matter reaches appeal, publication is effectively complete, because the appraisal and the review go into the appeal documents. How inspectors handle that material is set out in when an inspector reopens viability at appeal.

One honest point. Transparency has not stopped viability arguments, and some councils still accept appraisals that would not survive scrutiny. But the direction is settled, and an appraisal written for publication from the first draft costs less than one rewritten after a complaint.

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