Site allocations: what they commit you to

A local plan site allocation is an invitation with conditions attached. It does not grant permission, and it does not settle the principle of development in the sense that many applicants assume. What it does is commit you to the parameters written into the allocation policy and its supporting text: the quantum, the access point, the infrastructure, the phasing, the open space, the design framework and often a masterplan process you have to go through before anyone will validate an application.

Read the allocation as a specification. Then read the supporting text, because that is where most of the obligations actually sit.

How an allocation is expressed in a plan

An allocation has three parts and applicants routinely read only the first. There is the policies map, showing the boundary. There is the allocation policy, usually numbered, setting out the quantum and the requirements. And there is the supporting text, the paragraphs around the policy, which explain the intent and frequently contain requirements expressed as expectations rather than policy.

Section 38(6) of the Planning and Compulsory Purchase Act 2004 requires determination in accordance with the development plan unless material considerations indicate otherwise, so the allocation policy carries the weight of the plan. Supporting text is not policy and cannot be applied as though it were, but officers will use it to interpret the policy, and an inspector will read it as evidence of what the policy means.

Check three things on the boundary itself. Whether it matches the land you control, because allocations regularly include third party land. Whether it includes land you need for access, drainage or open space. And whether the area shown is the developable area or the gross site area, since the difference can be most of your yield.

Requirements embedded in the allocation policy

Allocation policies are dense. A typical one for a residential site of any size will specify an approximate number of dwellings, the access arrangement, a requirement for a masterplan or development brief agreed with the authority, affordable housing at the plan's rate, structural landscaping or a green buffer, on-site open space and play provision, a school or healthcare contribution, a drainage approach, heritage or ecology requirements specific to the site, and a phasing or trigger arrangement.

Two of those deserve early attention.

The approximate dwelling number is a ceiling in practice even when written as an approximation. An application for materially more than the allocated figure will be assessed against the policy and the evidence base behind it, and the density argument has to be made on its merits rather than assumed. Going materially below the figure is also a conflict, because the plan relies on the site to deliver its housing requirement.

The masterplan requirement is a gate. Where the policy requires a masterplan or development brief agreed with the authority, an application submitted without one can be resisted as premature, and on multi-ownership sites the masterplan is where the ownerships have to be reconciled. That takes longer than any other item, and it needs starting before the design work.

Infrastructure and phasing obligations

Infrastructure requirements in an allocation come with timing attached, and the timing is what constrains cash flow.

Grampian conditions and section 106 triggers are the mechanism: no more than a set number of dwellings occupied before a spine road is complete, before a junction is improved, before a school site is transferred, before open space is laid out, or before a drainage outfall is constructed. On larger allocations the triggers interlock, and a single late item stops occupations across the whole site.

Where the allocation is in multiple ownerships, the equalisation question arrives with the infrastructure. One party builds the access road and everyone benefits, which needs a collaboration agreement or an equalisation deed to resolve. Authorities increasingly write the requirement into the policy, expecting a single scheme for the whole allocation rather than a series of parcels. If you control one parcel of a larger allocation, your first task is to find out whether the policy will let you come forward alone.

Contributions and the levy sit alongside this. Where the authority charges the Community Infrastructure Levy, check how the charging schedule treats the allocation and what relief applies, and read the infrastructure delivery plan to see what the allocation was expected to fund.

Where an allocation conflicts with a constraint

Allocations are made on evidence available at the time, and sites change. A watercourse is remapped, a flood zone extends, a protected species turns up, a survey finds contamination, a building is listed, or a nutrient neutrality requirement arrives in the catchment after adoption.

An allocation does not override those. The plan-making process will have carried out a sustainability appraisal and, where relevant, a habitats regulations assessment, but that is a plan-level assessment and it does not answer the site-level question. Where a constraint discovered later reduces the developable area, the honest route is to apply for what the site can actually take and explain the evidence, rather than to press the allocated quantum because the plan says so.

This is where a careful sequence for constraint checking pays for itself before land is committed. Allocations look like certainty and are not, which is the same lesson the wider treatment of allocations as constraint and opportunity sets out.

An illustrative example. A site allocated for about 120 dwellings is found on survey to include 0.4 ha of previously unmapped priority grassland along one boundary and a groundwater-fed ditch that the drainage strategy cannot culvert. Retaining both, plus the buffers they need, takes the deliverable figure to around 95 units. An application at 95 with the ecology and drainage evidence attached is a stronger position than one at 120 with a weak justification for loss. The figures are illustrative.

Departing from an allocation's parameters

Departures happen and can succeed, but they need the right argument.

Where you propose a different access point, a different quantum, a different land use mix or a layout that abandons the design framework, the application is in conflict with the plan and has to be justified by material considerations. That means explaining why the allocation's assumption was wrong or has been overtaken, with evidence: a transport assessment showing the allocated access cannot be delivered safely, an ecological survey showing the allocated developable area was overstated, or a viability case showing the requirement cannot be met.

Argue the departure in the Planning Statement explicitly rather than presenting the scheme as compliant and hoping nobody compares it with the policy. Officers do compare, and a statement that glosses over a departure loses credibility on everything else.

Where the departure is fundamental, consider whether a plan review or a formal policy change is the better route. On a site that will be built over ten years, that is sometimes the shorter path.

Evidence base behind the allocation

The documents that justified the allocation are public and useful, and most applicants never read them.

1. The housing and economic land availability assessment entry for the site, which records the assumed capacity, density and constraints.
2. The sustainability appraisal, which shows which impacts were considered acceptable and on what basis.
3. The transport evidence, including any modelling of the allocated access.
4. The flood risk and water cycle studies, which may contain site-specific findings.
5. The infrastructure delivery plan, which sets out what the site was expected to contribute.
6. The examination library, including the inspector's report and any main modifications affecting the allocation.
7. The whole-plan viability assessment, which shows what policy burden the plan assumed the site could carry.

That last one is the most useful and the least used. Where a viability argument is likely, the assumptions the authority itself relied on at examination are the natural starting point, and a departure from them needs explaining by the authority rather than by you.

Using the allocation in your submission

Set out the allocation policy in full at the start of the planning statement, then work through each requirement with a paragraph saying how the scheme meets it or why it does not. Officers write reports in that structure, and a submission organised the same way is quicker to recommend.

Where a neighbourhood plan also covers the site, read it alongside the local plan, because a made neighbourhood plan forms part of the development plan and its policies can add requirements or, occasionally, conflict with the allocation. The weight given to neighbourhood plan designations is worth checking before you treat the local plan allocation as the last word.

One honest uncertainty. How strictly an authority applies an allocation's approximate figures varies with its housing land supply position, and an authority that cannot demonstrate a five year supply may be more receptive to a higher number than the same authority two years later. That is a moving target and worth testing at pre-application stage rather than assuming.

Browse all 66 report types on PlanScope to see which documents an allocated site application is likely to need.

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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