Five year housing land supply: how councils count it
Both sides of the five year supply ratio are contestable. Here is where the requirement figure comes from and what clear evidence of deliverability means.
A five year housing land supply is a ratio, and almost every argument about it is an argument about one of two numbers. On one side, how many homes the authority has to plan for over the next five years. On the other, how many are deliverable from sites it can identify. Divide the second by the annual requirement and you get the figure quoted in every appeal statement.
The calculation looks simple. It is not, because both numbers are contestable and the definition of deliverable does a great deal of work.
What the supply position actually measures
The requirement side starts with the authority's housing requirement, taken from strategic policies in a recently adopted plan, or from local housing need calculated by the standard method where the plan is older.
To that figure the council adds or subtracts an adjustment for past performance. Where past delivery has fallen short, the shortfall has to be dealt with, either by making it up within the next five years or by spreading it across the remaining plan period. Those two approaches are argued as the Sedgefield and Liverpool methods, and which one applies makes a material difference to the answer.
A buffer is then applied on top. The percentage, and the circumstances in which a larger buffer applies, have changed between editions of the National Planning Policy Framework, so check the current edition rather than repeating a figure from an older appeal decision. Framework editions were issued in December 2023, December 2024 and again in August 2026, and the August 2026 edition is organised by policy code rather than paragraph number.
Deliverable: the Annex 2 definition
The supply side is governed by the glossary definition of deliverable. Sites should be available now, offer a suitable location for development now, and be achievable with a realistic prospect that housing will be delivered on the site within five years.
The definition then splits sites into two groups.
| Site type | Treatment |
|---|---|
| Detailed planning permission, and small sites | Considered deliverable unless there is clear evidence that homes will not be delivered within five years |
| Outline permission, allocations, permission in principle, brownfield register sites | Only deliverable where there is clear evidence that homes will be delivered within five years |
That second row is where supply positions are won and lost. Clear evidence means something specific to the site: a signed contract, a developer on board with a stated programme, discharge of conditions under way, an active reserved matters application. A statement in a housing trajectory that a site "is expected to come forward" is not evidence, and inspectors have said so repeatedly.
Where the requirement figure comes from
The standard method produces a minimum starting point for local housing need. Its inputs and formula have changed, so quote the version in force and say which one you have used.
Two practical points for anyone testing a council's position. First, check whether the plan is recent enough for its own housing requirement to apply, since the answer changes the requirement figure and often the outcome. Second, check whether the requirement has been apportioned across a wider area under a strategic arrangement, because a district's share of a joint requirement is not always what the council's own document assumes.
Where a council is releasing land to meet a shortfall, the argument frequently moves onto constrained land, and the tests that apply there are different again from the supply arithmetic. That is the point at which very special circumstances in the Green Belt becomes the operative question rather than the supply figure itself.
How supply is contested at appeal
Appellants attack the supply by removing sites from it or by delaying their delivery. Councils defend it by evidencing progress. The recurring battlegrounds are worth knowing.
- Lead-in times: how long between a permission and the first completion, tested against the authority's own past record rather than a national average.
- Build-out rates: how many homes a year an outlet realistically delivers, and whether a large site has enough outlets to support the assumed rate.
- Lapse rates: what proportion of permissions never get built, and whether the council has applied any allowance.
- Double counting: sites appearing both as commitments and within an allocation total.
- Sites with unresolved constraints: nutrient neutrality, water neutrality, a section 106 not yet signed, or an outstanding highway agreement.
- The base date: whether the five years run from the base date of the assessment or from the date of the decision.
Viability is often the underlying issue on stalled sites. Where a site is not delivering because the numbers do not work, the debate turns on land value and the evidence behind it, which is the territory covered by benchmark land value in viability assessment.
What a shortfall does to decision-making
Where an authority cannot demonstrate the required supply, the policies most important for determining the application are treated as out of date, and the presumption in favour of sustainable development is engaged. In practice that shifts the balance towards granting permission unless the adverse effects would demonstrably and substantially outweigh the benefits, or unless policies protecting specific assets provide a clear reason for refusal.
It is not a green light. Protected designations, heritage assets, flood risk and habitats sites continue to operate as constraints, and a scheme with real harm still fails. What a shortfall does is remove the council's ability to refuse on housing policy grounds alone.
The weight given to a marginal shortfall varies. A supply of 4.9 years is treated differently from one of 3.2 years, and the extent of the deficit is a material consideration in its own right.
There is a second-order effect worth planning for. Once a shortfall is established at one appeal, it tends to be relied on at the next, until the council produces an updated position or wins an appeal on the point. Applicants with a site in a district that has just lost an appeal on supply have a window, and the sensible response is to get the application in while the evidence base is fresh rather than waiting for a design to be perfected.
Reading a council's published position
Most authorities publish an annual position statement or a five year supply paper. Read it with three questions in mind.
What base date does it use, and how much has changed since. Which method has been applied to any shortfall. And what evidence sits behind the largest sites in the trajectory, since removing two strategic sites can move a comfortable position into a deficit.
An illustrative example. An authority claims 5.4 years against a requirement of 600 homes a year. Two strategic allocations contributing 480 homes have outline permission but no reserved matters application and no developer identified. Remove them and the position falls below five years. The figures are illustrative only, but that pattern is common.
Set out your own supply analysis in the Planning Statement rather than in a separate note, and check what other documents the application needs alongside it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
Frequently asked questions
What does a five year housing land supply measure?
It compares the number of homes deliverable from identified sites over the next five years against five times the annual housing requirement, adjusted for any shortfall and with a buffer applied. The result is expressed in years of supply. Both the requirement figure and the deliverable supply are open to challenge at appeal.
What does deliverable mean?
Under the Framework glossary, sites should be available now, offer a suitable location for development now, and be achievable with a realistic prospect of delivery within five years. Sites with detailed permission and small sites are presumed deliverable. Outline permissions, allocations and brownfield register sites need clear site-specific evidence.
What is the difference between Sedgefield and Liverpool?
They are the two approaches to dealing with past under-delivery. The Sedgefield method makes up the accumulated shortfall within the next five years, which raises the annual requirement sharply. The Liverpool method spreads it across the remaining plan period. Which approach applies makes a material difference to whether a supply is demonstrated.
What happens if a council cannot demonstrate five years?
The policies most important for determining the application are treated as out of date and the presumption in favour of sustainable development is engaged. Permission should then be granted unless adverse impacts would demonstrably and substantially outweigh the benefits, or unless policies protecting specific assets give a clear reason for refusal.
How do appellants attack a supply position?
By testing lead-in times and build-out rates against the authority's own past record, arguing for a lapse rate allowance, identifying double counted sites, pointing to unresolved constraints such as nutrient neutrality or unsigned agreements, and disputing the base date. Removing two strategic sites often moves a position below five years.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.