Who can prepare a viability assessment councils accept

The viability assessment author a council will accept is a chartered surveyor with development appraisal experience, working to the professional standard on financial viability in planning, and independent of the land transaction being justified. Councils reject assessments on competence and conduct grounds more often than people expect, and the usual reason is not arithmetic. It is that the author has behaved as an advocate for the applicant while presenting the work as objective analysis.

Those are different roles, and the professional standard says so explicitly.

The professional standard the assessment must follow

The reference point is the professional statement published by the surveying institution on conduct and reporting in financial viability in planning. It sets out the behaviour expected of the practitioner rather than a calculation method, and the distinction matters.

Its requirements run to objectivity, impartiality, transparency about assumptions, disclosure of any conflict of interest, and a clear statement of the role being performed. A practitioner acting as an advocate must say so. A practitioner producing an objective assessment must not accept instructions that constrain the conclusion.

National practice guidance on viability sits alongside it and deals with method: benchmark land value established on the basis of existing use value plus a premium to the landowner, current costs and values rather than forecast growth, and a return to the developer that the guidance suggests may fall in the range of 15 to 20 per cent of gross development value, while noting that this can vary by circumstance.

Read both before commissioning. An assessment that follows the method and ignores the conduct requirements will be challenged on the ground where it is weakest.

Chartered surveying competence and specialism

Membership of the surveying institution is the baseline, and the relevant specialism is development appraisal rather than general practice valuation. Where the assessment includes a formal valuation, registered valuer status is expected.

What separates a credible author in practice:

• Experience of schemes of the same type and scale, with examples that can be named.
• Familiarity with the cost data sources used in the sector and the ability to justify departures from them.
• Experience of appearing at appeal or examination, because an assessment that will be tested benefits from an author who has been tested.
• Knowledge of the authority's own approach, including any local viability guidance and the reviewer it habitually appoints.
• Willingness to reach a conclusion the client will not like.

Our note on competence under the viability standards goes further into the grades and designations, and the broader question of what competent person means across planning legislation is covered in our note on competent person in planning legislation.

Transparency and the presumption of disclosure

The default is publication. National guidance proceeds on the basis that viability assessments should be publicly available, including those prepared at the plan making stage, other than in exceptional circumstances, and that any information withheld should be limited and presented in aggregated form.

Plan for that from the first instruction. An assessment written on the assumption that nobody outside the council will read it is a liability, because objectors, neighbouring landowners and other developers will read it, and inconsistencies with the applicant's public statements about the scheme will be found.

Practical consequences worth accepting early:

1. Do not include commercially sensitive material that is not needed for the conclusion.
2. Keep internal appraisal runs separate from the submitted document.
3. Expect the submitted inputs to be compared against your own marketing material.
4. Assume the assessment will be read alongside any Affordable Housing Statement you submit, and make the two consistent.

Requests to redact whole sections are usually refused and cost credibility. Aggregation is the accepted route.

Independence from the land transaction

This is the point that most often undermines an otherwise sound assessment.

The practitioner should not have advised on the acquisition of the site, should not be acting on a fee contingent on the outcome of the viability negotiation, and should disclose any other relationship with the applicant that a reasonable observer might consider relevant.

The reason is structural rather than moral. Guidance is clear that the price paid for land is not a justification for failing to meet policy requirements, and benchmark land value is assessed on existing use value plus a premium instead. An adviser who recommended the purchase price has an interest in defending it, and a council reviewer who spots that connection will discount the land value evidence entirely.

Where the same firm has acted on the acquisition, use a different firm for the viability work. The additional fee is smaller than the cost of losing the land value argument.

The council's own reviewer and how they test inputs

Authorities appoint an independent assessor, usually at the applicant's cost, and their approach is consistent enough to anticipate.

Abnormals are where most disputes concentrate. A lump sum for unspecified ground risk will be removed, while the same figure supported by an investigation report, a remediation strategy and a priced schedule will usually survive.

Supply the appraisal model itself rather than the printed outputs alone. A reviewer who has to rebuild your model will build it differently.

Where assumptions rather than arithmetic are challenged

Nobody disputes the multiplication. The arguments are about inputs and their justification.

Sales values are challenged where the scheme is priced against a different location or specification from the comparables. Programme is challenged where the phasing shifts costs early and revenues late, which depresses the residual. Growth assumptions are challenged because the guidance expects current values and costs rather than forecasts. Developer return is challenged where the risk profile does not support the figure, particularly on a scheme with pre-lets or forward funding in place.

And the existing use value is challenged whenever the existing use has effectively ceased. A vacant building with no lawful commercial occupier has a lower existing use value than a trading one, and applicants who inherit an optimistic figure from a land appraisal find that out at review.

Where you disagree with the reviewer, deal with it as an evidence question rather than a negotiation. Produce the comparable, the tender return, the investigation report. A Viability Assessment that responds to each challenged input with a document is in a much better position than one that restates the original figure.

Briefing and disclosure planning

Set the terms of engagement out in writing at the start, covering four things.

The role: objective reporting or advocacy, stated explicitly. The scope: the scheme as designed, the policy requirements tested, the sensitivity runs required. The disclosure position: what will be published, what will be aggregated and why. And the conduct position: confirmation that no fee is contingent on the outcome and that no conflict exists.

Then agree a data schedule. Cost information from the cost consultant, sales evidence from the agent, programme from the contractor, and the planning obligations schedule from the planning consultant. The viability practitioner assembles and tests those inputs rather than inventing them, and an assessment built on figures nobody owns is the one that collapses at review.

Where you need someone to review an assessment already prepared, the professional directory is the route to a reviewer who can check both the method and the conduct requirements. For specialist technical reports, qualified professional input may be required.

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