Five-year housing land supply
Can a council show enough deliverable land for the next five years of homes? If not, it is more exposed to development it did not plan for. Here is how the figure works, and why it matters so much.
What five-year housing land supply means
Every local planning authority must identify and update, each year, a supply of specific deliverable sites sufficient for at least five years of housing, plus a buffer. The result is usually expressed in years: a council with exactly enough land has 5.0 years; one with half the land it needs has 2.5 years.
In broad terms, a site is deliverable if it is available now, in a suitable location now, and there is a realistic prospect that homes will be completed on it within five years. Sites with detailed planning permission normally count. Sites with only outline permission, or only an allocation, need clear evidence that completions will begin within five years.
How it is calculated
The illustrative numbers below show the arithmetic. Real calculations depend on the applicable policy, the base date, the requirement, the buffer and the deliverability evidence.
| Step | Illustrative authority | Homes |
|---|---|---|
| 1. Annual housing requirement | From an up-to-date plan, otherwise local housing need | 1,000 |
| 2. Five-year requirement | 1,000 × 5 | 5,000 |
| 3. Add the buffer | 5% (normal case) | 5,250 |
| 4. Deliverable supply | Sum of deliverable sites over the five years | 3,885 |
| 5. Shortfall | 5,250 − 3,885 | 1,365 |
| Supply in years | 3,885 ÷ (1,000 × 1.05) | 3.70 years |
Which requirement?
Under the August 2026 Framework, if the housing requirement in the adopted plan is less than five years old (or has been reviewed and found not to need updating), supply is measured against that requirement. Once it is more than five years old, supply is measured against local housing need from the standard method, which starts from 0.8% of the existing housing stock and is adjusted upwards where homes are less affordable. For many older plans the standard method figure is much higher, which is why supply positions can fall sharply when a plan reaches its fifth birthday.
Buffers and the Housing Delivery Test
The Housing Delivery Test (HDT) is a separate, backward-looking measure: homes actually delivered over the last three years compared with the number required. The government publishes results each year; the 2025 measurement came out on 17 August 2026. Poor HDT results increase the land supply buffer and have other consequences:
| HDT result | Consequence |
|---|---|
| 95% or more | No consequence. A 5% buffer applies to five-year supply. |
| 85% to 94% | The council must prepare an action plan. |
| 75% to 84% | Action plan, and a 20% buffer on five-year supply. |
| Below 75% | Action plan, 20% buffer, and the council is treated as having evidenced unmet need for housing (Policy S5(1)(j)). |
Why it matters: the presumption in favour of development
Five-year land supply is the main way national policy tests whether a council is planning for enough homes right now. When a council cannot demonstrate it, national policy tilts decisions towards granting permission, so housing can come forward on land the council has not planned for.
That is what makes councils vulnerable. A shortfall attracts speculative applications on the edges of towns and villages. Refusals are more likely to be overturned at appeal, sometimes with costs awarded against the council, and the council loses some of its ability to steer growth through its plan. It is also why supply figures are fought over so hard at appeals and examinations.
Before and after 17 August 2026
Until 16 August 2026
The paragraph 11(d) "tilted balance"
If a council could not show a five-year supply (with the buffer), its policies for housing were treated as out of date. Permission should then be granted unless the adverse impacts would significantly and demonstrably outweigh the benefits, or protective policies gave a clear reason to refuse.
From 17 August 2026
Location first: Policies S3, S4 and S5
The presumption now starts with where a site is. Inside settlements (S4) there is a default "yes". Outside settlements (S5), only listed kinds of development get the same balance, and one of them, S5(1)(j), is housing that meets an evidenced unmet need. A five-year supply shortfall, or an HDT result below 75%, counts as that need.
A shortfall is not a blank cheque
Under S5, a scheme meeting unmet need must still be physically well related to an existing settlement and of a scale that existing or proposed infrastructure can support. Green Belt and Local Green Space have their own policies, and some national policies (for example on high flood risk) direct refusal regardless. Where the conditions are met, permission should be granted unless the adverse effects substantially outweigh the benefits; commentators note this is not necessarily the same test as the old wording.
Transition: the new decision-making policies applied from publication on 17 August 2026, including to applications already submitted. Local policies that are materially inconsistent with them now carry very limited weight.
Five-year supply calculator
Test the arithmetic, and see what happens if a large site delivers less than the council expects. For example, a strategic site forecast to deliver 400 homes in five years that only delivers 100.
| Five-year requirement with buffer | – |
| Supply after your adjustment | – |
| Supply as % of requirement | – |
| Shortfall | – |
Illustrative only. Real figures depend on the base date, the policy that applies and site-by-site evidence.
Why supply figures get disputed
- Deliverability: whether sites without detailed permission really will produce homes within five years.
- Lead-in times and build-out rates: how quickly large sites start and how many homes a year they produce.
- The base date: most councils use 1 April. A figure from an old base date can be out of date.
- The requirement: whether the plan's requirement or local housing need applies, and which buffer.
- Past under-delivery and windfalls: how they are treated in the calculation.
Inspectors at appeal often conclude that the supply is lower than the council claims. Our rankings show the council-published figure and its date, and will add figures found by inspectors where an appeal decision has tested them.