Deliverable sites and why the definition is argued
The glossary definition of a deliverable site decides most five year housing land supply arguments. Here is how the two site categories differ and what evidence moves a site across the line.
A deliverable site, in national policy terms, is one that is available now, offers a suitable location for development now, and is achievable with a realistic prospect that housing will be delivered on it within five years. That wording sits in the glossary to the National Planning Policy Framework rather than in a numbered policy, which is part of why the deliverable site definition for housing is argued over so hard at appeal. Where a council's five year supply rests on eight or nine large allocations, the dispute is almost never about the policy text. It is about whether the evidence behind each of those sites clears the glossary test.
The Framework was re-issued on 17 August 2026 and now uses policy codes in place of the old paragraph numbers, so read the glossary in the edition you are relying on before quoting it. The shape of the test has been stable across several editions. The list of site categories that need extra evidence has moved, and that is where arguments start.
What deliverable means in national policy
Three limbs, two of them in the present tense. Available now means the land is free of insurmountable ownership, tenancy or ransom strip problems. Suitable now means the site is acceptable in planning terms today, not after a plan review or a policy change. Achievable with a realistic prospect carries the forward look, and it is the limb that does the work.
The present-tense limbs matter more than people expect. A site allocated for 400 homes that still has a live occupational lease to 2031 is not available now, whatever the trajectory says. An authority that counts it anyway has misapplied the definition rather than simply taken an optimistic view.
Sites that need clear evidence
The glossary splits sites into two groups and flips the burden of proof between them.
| Site category | Starting position | Who must produce evidence |
|---|---|---|
| Non-major sites with permission, and all sites with detailed permission | Deliverable until the permission expires | The objector, to show homes will not come forward in five years |
| Outline permission for major development, plan allocations, permission in principle, brownfield register entries | Not deliverable unless shown otherwise | The authority, to show completions will begin within five years |
Read the second row carefully. The test is that completions begin within five years, not that the whole site builds out. An authority only has to get the first dwelling over the line inside the window, then justify the build rate it has assumed after that. Many trajectories fail on the second half rather than the first.
Evidence that satisfies an inspector
Inspectors are consistent about what counts. The material that moves a site into the deliverable column tends to be contractual or procedural rather than aspirational.
- A named housebuilder or registered provider with an interest in the land, evidenced by a contract, option or conditional sale
- Reserved matters submitted, validated or approved, with dates
- Pre-commencement conditions discharged, or an application to discharge them in the system
- A completed section 106 agreement rather than heads of terms
- Site preparation, demolition or infrastructure already under way
- A dated delivery statement from the landowner or developer that commits to a start, not an intention
A letter saying the owner hopes to begin in 2029 is evidence of intention. It is not evidence of a realistic prospect, and an inspector will say so. Equally, a council that has written to every allocation owner and received nothing back cannot treat silence as confirmation.
An illustrative worked position
Illustrative example. An authority claims 5.2 years of supply. Two allocations contribute 620 homes between them. One has outline permission and a signed contract with a national builder, with reserved matters validated three months ago. The other has an allocation, no permission, and a highway access that needs third party land. On the glossary test the first stays in. The second should come out in full, because the authority has no clear evidence that completions begin inside the window. Removing 310 homes from a supply of that size is usually enough to drop the figure below five years, and with it the weight of the development plan policies for housing supply.
Lapsed and stalled permissions
Permissions sitting unimplemented for years are the softest target in most supply statements. Where a detailed permission is still live, it counts until expiry unless there is clear evidence against delivery. Repeated section 73 applications to extend or vary, no commencement, and a site offered for sale as land rather than as a consented scheme are all evidence against.
Where a permission has lapsed and been renewed, ask what changed. A renewal with no build contract, no discharge of conditions and no change in the owner's position is a procedural event, not a delivery event. And where a site has slipped in three consecutive annual monitoring reports, that history is admissible and far more persuasive than any single document.
Why the definition decides supply arguments
If a council cannot demonstrate the supply the Framework requires, the presumption in favour of sustainable development engages and the tilted balance applies to the decision. That is the practical prize. Arguing about the glossary definition of one allocation is not pedantry when the result changes how much weight the decision maker gives to restrictive plan policies.
This is also why the analysis belongs in the application documents from the start, not saved for an appeal statement. A Planning Statement that sets out a site-by-site supply critique with dated evidence puts the case officer on notice and gives the committee report something it has to address. For schemes where the economics are also in play, the same discipline applies to a Viability Assessment, where benchmark assumptions need the same contractual grounding.
Challenging an authority's trajectory
- Get the base date right. Supply is measured from a stated base date, and anything granted or completed after it belongs in a different year.
- Download the full trajectory, not the summary table, and ask for the site-by-site assumptions behind it.
- Sort sites into the two glossary categories before looking at numbers at all.
- For every category (b) site, ask one question: where is the clear evidence that completions begin within five years.
- Test the build rates. Two outlets on a 500 home site will not deliver 150 homes a year because the trajectory needs them to.
- Recalculate with and without the disputed sites, and show both figures.
Councils do the same exercise in reverse, and a trajectory backed by dated correspondence with every owner is hard to dislodge. Where the authority has done that work properly, pick a different argument.
Presenting the analysis
Put the conclusion in the first paragraph of the supply section, then the table, then the evidence for each disputed site. Avoid a narrative that makes the reader reconstruct your arithmetic. Where a scheme relies on a supply shortfall, say plainly what the figure becomes on your analysis and what follows from it.
One honest uncertainty: inspectors differ on how much weight to give a developer's own delivery statement where that developer is the appellant. Some treat it as the best available evidence. Others discount it as self-serving. Pair it with something external, such as a signed contract or a discharged condition, wherever you can. Related reading on supply-adjacent policy routes sits in the guide to First Homes exception sites and their tests.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.
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Frequently asked questions
Where is the definition of a deliverable site found?
It sits in the glossary to the National Planning Policy Framework rather than in a numbered policy or a policy code. The Framework was re-issued on 17 August 2026, so read the glossary in the edition you are relying on. Planning Practice Guidance on housing supply and delivery explains how the definition feeds into the five year calculation.
Does a site with detailed planning permission always count as deliverable?
It counts until the permission expires unless there is clear evidence that homes will not be delivered within five years. Repeated variation applications, no discharge of pre-commencement conditions and the land being marketed without a consented scheme are the kinds of evidence that rebut the starting position.
What does clear evidence actually mean for an allocation?
Something contractual or procedural rather than aspirational. A signed option or conditional sale with a named builder, validated reserved matters, discharged conditions, a completed section 106, or site works already started. A letter stating an intention to begin in a future year is not enough on its own.
Does the whole site have to build out within five years?
No. For allocations and outline permissions the test is that housing completions begin on site within five years. The build rate assumed after that first completion is a separate argument, and trajectories are more often successfully challenged on unrealistic annual rates than on the start date.
What happens if the council cannot demonstrate five years of supply?
The presumption in favour of sustainable development engages and the tilted balance applies, which reduces the weight given to development plan policies for the supply of housing. That is why a site-by-site critique of the trajectory is worth preparing properly rather than asserting a shortfall.
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.