Base Housing Requirement
Use the applicable adopted strategic requirement or local housing need figure, taking account of plan age, review status, stepped requirements and the relevant geography.
A Forward-Looking Delivery Calculation
What a Five-Year Housing Land Supply Is Designed to Measure
The calculation asks whether enough homes are realistically expected from specific deliverable sites over the next five years.
Five-year housing land supply is often shortened to “5YHLS”. Annex D of the August 2026 NPPF requires the authority to compare the applicable five-year housing requirement, including the correct buffer, with completions expected from specific deliverable sites.
The supply side should include only homes expected to be completed within the relevant five-year period. A site cannot be counted merely because it appears in a HELAA, Local Plan or landowner submission. Its planning status, availability, suitability, achievability, infrastructure and realistic programme must support the claimed completions.
The requirement side normally uses the adopted strategic housing requirement where the relevant policies were adopted or reviewed within the preceding five years and remain appropriate. In other circumstances, the Annex D standard-method local housing need figure is generally used, together with any relevant shortfall and the applicable 5% or 20% buffer.
A failure to demonstrate the required supply now provides evidence of unmet housing need for policy S5(1)(j). That policy concerns qualifying development outside settlements which is physically well-related to an existing settlement and appropriately scaled for its infrastructure. Within settlements, policy S4 applies. Green Belt proposals must follow the separate GB7 route.
The position is date-sensitive. Permissions are granted, sites lapse, build-out rates change and monitoring evidence is updated. The base date, evidence date, five-year period and trajectory should therefore be recorded precisely.
Five-year supply is not the number of years until the council runs out of land. It is an Annex D calculation comparing a buffered five-year requirement with homes expected from deliverable sites.
The Four Main Parts of the Calculation
A reliable assessment keeps the requirement, shortfall, buffer and deliverable supply visible rather than relying only on the final headline.
Past Shortfall
Any deficit against the planned requirement is normally added to the next five-year period using the approach set out in national guidance.
Appropriate Buffer
Add the applicable 5% or 20% buffer to the first five years, including shortfall. Buffers are alternatives rather than cumulative additions.
Deliverable Supply
Total the net completions realistically expected from specific sites within the five years, supported by robust and up-to-date evidence.
The denominator must be correct
Which Housing Requirement Should Be Used?
Using the wrong base requirement can change the result before any individual supply site is considered.
Where adopted strategic housing policies are less than five years old, their requirement is normally used. The same can apply to older policies that have been reviewed within the last five years and found not to require updating. The date and scope of the review should be identified rather than assumed from general plan-review activity.
Where the strategic policies are more than five years old and have not been reviewed and found up to date, the area’s local housing need calculated through the standard method is normally used. The current input data and calculation date matter because the figure can change.
A plan may contain stepped requirements, joint-area requirements or more than one strategic policy. The calculation should follow the relevant period and geography. Where requirements conflict, the most recently adopted strategic policy may govern. A high-level statement that the plan is “old” is not enough to establish the correct denominator.
Past under-delivery is a separate adjustment. National guidance states that the deficit should normally be added to the requirement for the next five-year period, often described as the Sedgefield approach, before the appropriate buffer is applied.
The Five-Year Housing Land Supply Buffers
Only one buffer is applied. The correct choice depends on current national policy and the authority’s circumstances.
| Buffer | When it applies | Practical effect |
|---|---|---|
| 5% | The minimum buffer for authorities where neither 20% test applies. | Adds choice and competition by moving additional requirement into the first five years. |
| 20% for under-delivery | Where housing delivery over the previous three years has fallen below 85% of the requirement in the latest Housing Delivery Test. | Raises the five-year requirement and can make an existing claimed supply insufficient. |
| 20% where a recent requirement is 80% or less of current need | For decision-making where a requirement adopted in the last five years was examined against a pre-12 December 2024 NPPF and the annual average requirement is 80% or less of the latest local housing need figure. | Addresses recently adopted requirements materially below the current standard-method need. The policy does not create a separate cumulative buffer. |
This additional 20% buffer is now contained in Annex D for decision-making. The precise adopted requirement, examination framework and current local housing need figure should be evidenced.
Current policy position
Could the Council’s Housing Supply Affect Your Site?
We can review the authority’s latest published supply, requirement, buffer and Local Plan position before you decide whether an application, representation or further site evidence is justified.
Deliverable and Developable Are Different Tests
A site may be suitable for the longer term without being capable of contributing completions within five years.
Deliverable Within Five Years
A deliverable housing site must be available now, offer a suitable location now and be achievable with a realistic prospect that housing will be delivered within five years.
Small sites with permission and sites with detailed permission are generally treated as deliverable until permission expires unless clear evidence indicates otherwise. That does not require every permitted dwelling to be completed within five years; the trajectory still needs a realistic build-out assumption.
Major outline permissions, allocations, permission-in-principle sites and brownfield-register sites require clear evidence that housing completions will begin within five years.
Developable in a Later Period
A developable site should be in a suitable location with a reasonable prospect that it will be available and could be viably developed at the point envisaged.
This is the relevant concept for years beyond the immediate five-year deliverable period. Strategic infrastructure, land assembly or planning work may mean a site is credible for years 6–10 or later but not part of the current five-year supply.
Describing a long-term site as strategic or developable should not be used to inflate the deliverable trajectory. Timing is part of the definition.
Evidence That May Support Deliverability
The necessary evidence depends on the site category, scale and stage. A generic owner intention is rarely enough for a complex major site.
Planning Progress
Detailed permission, reserved-matters submissions, condition-discharge work, a planning performance agreement or a clear application programme can support the claimed start date.
Developer Commitment
Written evidence of ownership, control, funding, delivery intentions and anticipated start and build-out rates can demonstrate that the trajectory is more than aspiration.
Infrastructure Programme
Highways, utilities, drainage, schools and other enabling works must be funded, consented and timed consistently with the housing completions claimed.
Viability and Funding
Affordable housing, section 106, CIL, remediation and abnormal costs should not make the delivery assumption unrealistic. Public funding or grant commitments may be relevant.
Lead-In and Build-Out
Comparable site evidence, contractor or developer programmes and the scale of outlets should support the time allowed from permission to start and annual completions.
Landowner and Stakeholder Position
Multiple ownerships, tenancies, ransom interests, relocation and unresolved agreements can delay delivery even where the planning principle is supported.
The trajectory must be tested site by site
Common Areas of Dispute in a Five-Year Supply Case
Most challenges concern the timing or number of completions rather than whether a site could ever be developed.
Outline permissions and allocations: a council may include ambitious early completions without showing reserved-matters progress, developer commitment or a credible route through conditions and obligations. The challenge should identify the missing evidence and propose a justified alternative trajectory.
Large-site lead-in times: strategic sites may require land assembly, infrastructure design, procurement, remediation and multiple approvals before the first home is completed. A start on site is not the same as a housing completion, and construction of enabling works may occupy a substantial period.
Build-out rates: annual completions depend on market outlets, tenure mix, developer numbers, infrastructure triggers and local demand. A historic average can inform the assessment, but site-specific evidence may justify a different rate.
Lapse, non-implementation and double counting: permissions that are unlikely to proceed, expired permissions, duplicated phases and homes already counted as completions can overstate supply. Net figures should account for demolitions where relevant.
Windfall assumptions: a reliable allowance should be supported by compelling evidence that such sites have consistently become available and will continue to provide a dependable source. The evidence should avoid counting sites already identified elsewhere in the trajectory.
Infrastructure and viability: a site may have permission but still depend on an unfunded junction, wastewater solution, school, grid connection or remediation programme. The supply should reflect the realistic date at which the impediment can be resolved.
A credible challenge identifies the disputed dwellings, explains why the published delivery date is unsupported and supplies evidence for a more realistic alternative.
How to Review a Council’s Published Position
The headline years-of-supply figure is the final step, not the starting point.
Record the Base Date
Identify the first day of the five-year period, the date of the evidence and whether later permissions or completions have been consistently included.
Check the Requirement
Confirm plan age, review status, standard-method need, stepped requirements, past shortfall and geography.
Apply the Correct Buffer
Use the latest Housing Delivery Test and consider the additional decision-making buffer effective from 1 July 2026 where its conditions are met.
Reconcile the Supply List
Check permissions, allocations, windfalls, demolitions, completions and phasing to ensure sites and dwellings are not duplicated.
Test Major Sites
Review planning progress, developer control, infrastructure, viability, lead-in times and build-out assumptions for every material contributor.
Calculate the Result
Divide the deliverable supply by the annualised buffered requirement, while retaining the dwelling totals and assumptions behind the final years figure.
Related but Separate Monitoring Measures
Five-Year Supply and the Housing Delivery Test
Both can affect housing decisions under the August 2026 NPPF, but they measure different things and should not be conflated.
The Housing Delivery Test looks backwards. It compares homes delivered during the previous three years with the number required for that period. A result below 95% requires an action plan, below 85% also applies a 20% five-year supply buffer and below 75% is treated as evidence of unmet housing need for S5(1)(j). The calculation and consequences are explained in our Housing Delivery Test guide.
Five-year supply looks forwards. It tests whether specific deliverable sites are expected to provide enough homes over the next five years. The Housing Delivery Test can determine the under-delivery buffer, but it does not populate or validate the list of deliverable sites.
An authority can therefore have a delivery issue, a supply issue or both. The planning statement should identify the current result, the current supply calculation and the location-specific S4, S5 or Green Belt route that applies to the proposal.
What a Shortfall Does and Does Not Mean
The Consequences for a Planning Application
A lack of five-year supply remains important, but it no longer engages the former paragraph 11(d) two-limb tilted balance.
For qualifying housing outside settlements, failure to demonstrate the required supply is evidence of unmet need for S5(1)(j). The proposal must be physically well-related to an existing settlement, appropriately scaled having regard to infrastructure and acceptable when assessed against the remaining national decision-making policies.
For housing within a settlement, S4 applies. For land in the Green Belt, the relevant route is GB7, including its separate tests for previously developed land, grey belt, well-connected stations and other specified development. A supply shortfall does not disapply those routes.
Annex A may also prevent a higher current need figure from being treated as unmet need for S5(1)(j) for five years after adoption where the relevant recently adopted plan can demonstrate the required supply and Housing Delivery Test performance exceeds 75%.
Safe access, flood risk, ecology, landscape, heritage, infrastructure, design, living conditions and deliverability remain material. A weak site does not become suitable merely because the council’s supply is 4.9 years rather than 5.1.
The correct question is not simply whether the council has a five-year supply, but which August 2026 policy route applies to the exact site and whether the proposal satisfies all of its cumulative requirements.
Site-specific evidence still matters
A Supply Shortfall Is Most Useful Where the Land Can Deliver
We can review the housing supply position alongside location, access, policy, constraints and a realistic development programme to identify whether further planning work is justified.
Evidence a Landowner Can Provide About Their Own Site
Positive delivery evidence can assist both Local Plan monitoring and a planning application.
Confirm Availability
Provide ownership, control, tenancy and land-agreement information showing that the site can be brought forward within the claimed period.
Set Out Planning Progress
Identify pre-application work, submission dates, application type, reserved matters and conditions. See the planning application types guide.
Explain Infrastructure
Show how access, drainage, utilities and other enabling works will be approved, funded and delivered without delaying completions.
Provide a Realistic Programme
Separate planning, condition discharge, site preparation, construction start and first completions. Support build-out rates with developer or comparable evidence.
Address Viability and Obligations
Explain how affordable housing, section 106, CIL, abnormal costs and funding affect the timing and scale of delivery.
Keep the Evidence Current
Update the council when ownership, developer involvement, planning status or delivery timing changes. Old intentions can undermine confidence in the trajectory.
Check the date before relying on the number
Why the Housing Supply Position Can Change Quickly
Supply statements, appeals and Local Plan evidence are snapshots rather than permanent findings.
A new permission can add dwellings, but only to the extent that completions are deliverable within the relevant period. Conversely, delay on one large strategic site can remove hundreds of claimed completions. Updated local housing need, a new Housing Delivery Test result or the adoption of a plan can also change the requirement or buffer.
Applications and appeals should use the latest robust evidence available at the decision date. A council may publish an annual statement, but parties can rely on later material evidence where it demonstrates that the trajectory has changed. The source and date of every figure should therefore be stated.
This guide reflects the published national policy and guidance position available in August 2026, including the additional buffer effective from 1 July 2026. Future NPPF or guidance changes should be checked before the page or a planning case is relied upon.
How Value My Land approaches the issue
Our Initial Housing Supply and Site Review
We consider whether the current supply position is material to the site rather than treating a shortfall as a standalone planning strategy.
We can review the council’s published years-of-supply figure, base date, requirement, buffer and principal disputed sites at a high level. We then consider the land’s settlement relationship, policy status, access, constraints and likely delivery route.
Where the supply position may support an application, the next step may be a planning strategy, technical constraints review, concept masterplan and more detailed assessment of the authority’s trajectory. Where the site is more appropriate for the Local Plan, a Call for Sites or allocation route may remain preferable.
Our free initial review is not an appeal proof, expert witness report or substitute for specialist planning advice. Its purpose is to identify whether five-year supply is likely to be a material opportunity, a disputed background issue or largely irrelevant because another policy or technical constraint is decisive.
Housing supply, plan-making and planning decisions
Related Guides
These guides explain the August 2026 presumption, allocations, settlement policies, land assessments and application routes that interact with five-year housing land supply without duplicating its calculation. For the underlying requirement side of the equation, see Housing Need and Housing Targets in England.
Presumption in Favour of Sustainable Development
Understand how a supply failure can evidence unmet need for S5(1)(j) and why S4 and GB7 may provide the relevant route elsewhere.
Read the guidePlanning Policy and Development Land
See how the development plan, national policy and material considerations combine in planning decisions.
Read the guideLocal Plan Allocation Guide
Learn how councils select, consult upon, examine and adopt sites for future development.
Read the guideSettlement Boundaries Guide
Understand how mapped development limits interact with housing need, plan review and planning applications.
Read the guideCall for Sites Guide
Find out how land is submitted for consideration and why supply evidence does not itself allocate a site.
Read the guideWhat Is a HELAA or SHLAA?
Read how land availability evidence supports plan-making and can inform the council’s housing trajectory.
Read the guideSuitable, Available and Achievable Sites
Understand the related assessment tests and how they differ from the stricter five-year deliverability question.
Read the guideWhat Is Strategic Land?
Explore the medium- and long-term promotion of land that may not yet be capable of contributing within five years.
Read the guideTypes of Planning Applications in England
Compare outline, full, reserved-matters, permission-in-principle and other application routes relevant to delivery.
Read the guideFrequently Asked Questions About Five-Year Housing Land Supply
What is a five-year housing land supply?
It is a supply of specific deliverable housing sites sufficient to provide five years’ worth of housing against the applicable adopted housing requirement or, in some circumstances, local housing need, together with the appropriate buffer. It is a calculation of expected housing delivery, not simply a list of land with planning potential.
Why is a buffer added?
The buffer moves additional supply forward from later in the plan period to improve the prospect of meeting the planned requirement and provide choice and competition. The buffers are not cumulative. The applicable buffer is generally 5% or 20%, depending on delivery and, from 1 July 2026, the additional circumstances specified in national policy.
What changed on 1 July 2026?
For decision-making, a 20% buffer also applies where an authority has a housing requirement adopted within the previous five years, that requirement was examined against an NPPF published before 12 December 2024, and its annual average requirement is 80% or less of the latest local housing need figure. The authority’s current calculation should be checked carefully because the policy is technical.
What does deliverable mean?
A housing site must be available now, in a suitable location now and achievable with a realistic prospect of delivery within five years. Small sites with permission and sites with detailed permission are generally treated as deliverable unless clear evidence indicates otherwise. Major outline permissions, allocations, permission-in-principle sites and brownfield-register sites require clear evidence that completions will begin within five years.
Does an allocation automatically count in the supply?
No. An allocation can provide policy support, but a major allocated site requires clear evidence of delivery within five years before it can be counted as deliverable. Planning progress, ownership, infrastructure, viability, developer commitment, lead-in time and build-out rates may all be relevant.
Does outline planning permission automatically make a major site deliverable?
No. A major site with outline permission falls within the category requiring clear evidence that housing completions will begin within the five-year period. Reserved matters, conditions, section 106 obligations, infrastructure, developer control and realistic phasing should be examined.
Is the Housing Delivery Test the same as five-year supply?
No. The Housing Delivery Test looks backwards at delivery against the requirement over the previous three years. Five-year supply looks forwards at deliverable sites over the next five years. The Test can determine the 20% under-delivery buffer and, below 75%, can evidence unmet need for S5(1)(j), but it is not the five-year supply calculation itself.
Does a shortfall guarantee planning permission?
No. A failure to demonstrate the required supply can evidence unmet housing need for S5(1)(j) for qualifying housing outside settlements, but the site must meet that policy’s relationship and infrastructure tests and all other national decision-making policies. S4 applies within settlements and GB7 provides the separate Green Belt routes. Read the NPPF 2026 presumption guide.
Can a landowner challenge a council’s supply?
Potentially. A challenge should identify the applicable requirement, buffer, shortfall and disputed sites, then provide evidence about planning status, developer commitment, infrastructure, lead-in time and build-out. It is not enough to assert that a council’s published number is old or optimistic without examining the trajectory site by site.
Can Value My Land confirm the exact supply position?
We can undertake a high-level review of the council’s published position and whether the issue may affect a site. A formal application or appeal case may require detailed planning evidence, trajectory analysis and specialist advice based on the latest documents and decision date.
Review Whether Housing Land Supply May Affect Your Site
Send us the land location and local planning authority. We can undertake a free initial review of the published supply position and the site’s planning context.
A shortfall is not automatic permission, but where the land is well located and deliverable it may form an important part of the planning strategy.