5 year housing land supply explained

 

A 5 year housing land supply, usually shortened to 5YHLS, is the pipeline of specific deliverable housing sites that a local planning authority must be able to identify for the next five years. It is one of the most important housing figures in planning because a failure to demonstrate the required supply can materially strengthen the case for new housing, particularly outside settlements.

The August 2026 National Planning Policy Framework changed some of the rules around the calculation and, importantly, changed what a shortfall does in decision-making. This page explains the current baseline, what counts as a deliverable site, the 5% and 20% buffers, the links with the Housing Delivery Test, and what happens when a council falls short.

 

What a 5 year housing land supply is

 

Local planning authorities in England must identify and update annually a supply of specific deliverable housing sites. The supply is measured against the relevant annual housing requirement, with an appropriate buffer added on top.

The point is not merely to show that enough land could theoretically accommodate five years of housing. The sites counted in the five year supply must have a realistic prospect of delivering homes within that period. That is why the planning status, infrastructure, ownership, viability and actual delivery evidence for individual sites can become central issues at an appeal.

 

Which housing figure is the five year supply measured against?

 

Under Annex D of the August 2026 NPPF, the starting point is the housing requirement in the development plan. Where that housing requirement is more than five years old, the five year supply is instead assessed against the authority’s local housing need, calculated using the standard method.

This is an important change of emphasis. Under older national guidance, an older housing requirement could continue to be used where the relevant strategic policies had been reviewed and found not to require updating. The August 2026 Framework no longer uses that as the baseline rule for the five year supply calculation.

Our guide to local housing need and the standard method explains the calculation and, importantly, why local housing need is not automatically the same as the adopted housing requirement. For the five year supply, the key point is simple: once the relevant development plan housing requirement is more than five years old, Annex D points the calculation to local housing need.

 

What counts as a deliverable housing site?

 

A site must be available now, be a suitable location for housing now and be achievable with a realistic prospect that housing will be delivered within five years.

The NPPF then distinguishes between sites which are treated as deliverable in principle and sites where further evidence is required:

• non-major sites with planning permission, and all sites with detailed planning permission, should be considered deliverable until the permission expires unless there is clear evidence that the homes will not be delivered within five years;
• a major site with outline planning permission, a site allocated in the development plan, a site with permission in principle or a site identified on a brownfield register should only be counted as deliverable where there is clear evidence that housing completions will begin within five years

This is why simply pointing to an allocation or a large outline permission is not enough. On those sites the authority needs evidence of actual progress and realistic delivery.

 

The 5% and 20% buffers

 

The five year requirement is not the end of the calculation. An additional buffer is applied to provide headroom, choice and competition in the land market. The important point is that the buffers are alternatives, not cumulative additions. An authority applies the relevant 5% or 20% buffer; it does not stack several buffers on top of one another.

• 5% is the normal minimum buffer
• 20% applies where the most recent Housing Delivery Test shows delivery below 85% of the requirement over the previous three years
• A separate 20% decision-making buffer applies in specified circumstances where the authority has a housing requirement examined against national policy published before December 2024 and its annual average housing requirement is 80% or less of the most up-to-date local housing need figure

The final NPPF also extends that third route to certain older housing requirements where the relevant plan policies have been reviewed and found not to require updating. This is easy to miss: such a review no longer keeps the old requirement as the baseline for the five year calculation once it is over five years old, but it can still be relevant to whether this particular 20% decision-making buffer applies.

You will sometimes hear a 20% buffer described as requiring a “six year supply”. That is useful shorthand, but it is not technically a separate six-year test. The buffer is applied to the relevant five-year requirement and any applicable shortfall, so the exact number of dwellings required depends on the authority’s calculation.

 

How the Housing Delivery Test fits in

 

The Housing Delivery Test (HDT) looks backwards at how many homes have actually been delivered against the relevant requirement over the previous three years. Five year housing land supply looks forwards at the deliverable pipeline. The two tests are different, but their policy consequences overlap.

• Below 95% HDT performance, the authority must prepare an action plan
• Below 85%, the 20% housing land supply buffer applies as well
• Below 75%, national policy treats that as evidenced unmet housing need for the purposes of S5, in addition to the action plan and 20% buffer consequences

Failure to demonstrate the required five year housing land supply, including the appropriate buffer, is also expressly treated as evidence of unmet housing need under S5.

 

What happens when a council cannot demonstrate the required supply?

 

The August 2026 NPPF changed the decision-making consequence. Before August 2026, a five year supply shortfall was closely associated with the old paragraph 11(d) tilted balance. That mechanism has now gone.

Under the current Framework, failure to demonstrate the required five year supply is expressly treated as an evidenced unmet need for housing for the purposes of policy S5(1)(j). For suitable housing outside a settlement, that can bring a proposal within the S5 category which receives the favourable national policy balance. Our guide to building outside a settlement boundary applies that test to infill and edge-of-settlement sites, while the presumption in favour of sustainable development page explains the wider balance.

Within a settlement, S4 already supplies its own strongly supportive policy balance. A five year supply shortfall is still relevant evidence, but it is not a switch that turns S4 on.

Nor is a five year supply shortfall needed for every S5 route. For example, redevelopment of previously developed land under S5(1)(d) is a separate category which does not depend on a housing land supply failure.

 

What about Green Belt?

 

A housing land supply shortfall does not simply override Green Belt policy. Green Belt proposals must be assessed under the separate Green Belt decision-making policies.

However, the supply position can still be directly relevant. Under the grey-belt provisions, a failure to demonstrate the required five year housing land supply can satisfy the evidenced-unmet-housing-need limb of the policy. The remaining Green Belt tests still have to be met, and major development may also have to comply with the Golden Rules.

See our guide to grey belt, Green Belt, greenfield and brownfield land.

 

A protection for some recently adopted plans

 

Annex A contains an important qualification to the new unmet-need policy. Broadly, during the first five years following adoption of a development plan, where the authority can demonstrate the required five year housing land supply including the appropriate buffer and its Housing Delivery Test performance is above 75%, the fact that current local housing need is higher than the adopted plan housing requirement does not, by itself, establish an unmet housing need for S5(1)(j).

This protection is about the difference between the adopted requirement and current local housing need. It does not protect an authority which actually fails the five year supply test or falls below the relevant Housing Delivery Test threshold.

 

How can a five year housing land supply shortfall help a planning application?

 

A shortfall matters differently depending on where the site lies and why the authority’s supply figure is weak. These simplified examples show the main routes.

Example 1: housing just outside a settlement where supply is only 4.2 years

Situation: A suitable housing proposal lies outside the settlement and the authority cannot demonstrate the required five year supply, including the correct buffer.

What helps: The shortfall is expressly treated as evidence of unmet housing need for S5(1)(j). That can bring the proposal within an S5 route which receives the favourable national decision-making balance.

What could still defeat it: The site and scheme still have to satisfy the relevant S5 requirements and the other national decision-making policies. Landscape, access, flooding, heritage and design remain capable of outweighing the benefits.

Example 2: the same 4.2-year supply, but the site is within a town

Situation: Housing is proposed on a brownfield or under-used site within an existing settlement.

What helps: This is primarily an S4 case. S4 already supplies the supportive national-policy balance, so the 5YHLS shortfall is not what turns that support on. It can nevertheless strengthen the evidence about housing need and the benefits of delivering homes.

Planning Geek view: Do not force an S5 argument onto an urban S4 site. Use the shortfall as supporting evidence while the location, efficient use of land and quality of the scheme do the main work.

Example 3: the council claims 5.1 years, but a large outline site looks doubtful

Situation: The published headline is just above five years, but a significant part of the trajectory depends on a major outline permission with little evidence of infrastructure, reserved matters or an imminent start.

What helps: Major outline sites are not simply assumed to be deliverable. If the evidence does not show a realistic prospect of completions beginning within five years, the claimed contribution can be challenged. Removing or reducing one large site can sometimes change the authority’s overall position.

What still matters: A challenge needs evidence. The fact that a site is large, slow or inconvenient is not enough by itself to remove it from the supply.

Example 4: HDT is 80% and the 20% buffer changes the answer

Situation: The authority appears to have a comfortable pipeline before the buffer is applied, but its most recent Housing Delivery Test result is below 85%.

What helps: The 20% buffer increases the supply the authority must demonstrate. On a marginal case, applying the correct buffer can turn an apparent five year supply into a shortfall, which then has its own decision-making consequence under S5.

Planning Geek tip: Never rely only on the council’s headline number. Check the baseline housing figure, the correct buffer and the deliverability of the largest sites in the trajectory.

 

Important August 2026 note on Planning Practice Guidance

 

As at 24 August 2026, the Government’s live Housing Supply and Delivery Planning Practice Guidance is still dated 12 December 2024. Some passages therefore describe the previous NPPF wording, including the former rule about older housing requirements which had been reviewed and found not to need updating.

The August 2026 NPPF is the newer national policy. Until the PPG is revised, it is important to check the wording in Annex D of the current Framework rather than relying on older paragraph references or assuming every part of the existing PPG has already caught up.

 

Can the council’s figure be challenged?

 

Yes. Authorities update their supply position regularly, but the published headline figure is not immune from challenge. Disputes commonly turn on whether particular sites really satisfy the deliverability definition, how many homes will be completed within five years, the applicable requirement and buffer, and whether evidence about infrastructure, ownership, viability or build-out is sufficiently robust.

That is why two parties to the same appeal can produce materially different five year supply figures. The real argument often lies in the site-by-site trajectory rather than the council’s headline number.

 

What it costs, and appealing a refusal

 

There is no separate fee for making a five year housing land supply argument. It forms part of the planning merits of an application or appeal. See our guide to current planning application fees.

If an application is refused, the applicant can normally appeal and the housing supply evidence may become a major part of the case. Our planning appeals section explains the available routes and deadlines.

 

Where to go next

 

Five year housing land supply sits within a wider housing evidence chain. Our SHLAA guide explains how potential housing land is identified, the Housing Delivery Test measures past delivery, and our guide to local housing need and the standard method explains the housing figure that can become the 5YHLS baseline once an adopted requirement is more than five years old.

 

 

Relevant policy for a 5 year housing land supply

 

The five year housing land supply rules are principally national planning policy rather than a standalone statutory calculation. For current decision-making, the most useful provisions are:

• National Planning Policy Framework (August 2026) — particularly Annex D on housing supply and delivery, S5(1)(j) on evidenced unmet need, Annex A on implementation and the relevant Green Belt policies;
• Planning Practice Guidance: Housing Supply and Delivery — useful supporting guidance, but note the August 2026 warning above while the page still contains pre-August-2026 NPPF references;
• Planning Practice Guidance: Housing and Economic Needs Assessment — including the standard method used to calculate local housing need

 

Other Housing Sections

 

 

5 Year Housing Land Supply Page Updated: 30th August 2026