The retail sequential test: building an area of search

The retail sequential test area of search is the single decision that determines whether your assessment survives scrutiny. Draw it too wide and you import town centre sites that could never serve the catchment you are aiming at. Draw it too narrow and the authority will say you have excluded the obvious alternative. Everything else in a sequential test, the site-by-site reasoning, the flexibility argument, the availability evidence, is downstream of that one line on a plan.

National policy requires the test for main town centre uses that are neither in a centre nor in accordance with an up-to-date development plan. The structure is a preference, not a prohibition: centre first, then edge of centre, then out of centre, with the applicant expected to show flexibility on format and scale along the way.

What the test actually asks

The question is whether a sequentially preferable site is available and suitable for the development proposed. Not whether a smaller shop could go somewhere else, and not whether the town would be better served by a different scheme.

That reading comes from the Supreme Court in Tesco Stores Ltd v Dundee City Council, which held that suitability is judged by reference to the development the applicant proposes rather than to some other development the decision maker might prefer. Applicants still have to be flexible, but flexibility has limits and the case gives those limits a legal footing.

Two things the test is not. It is not an impact assessment: the question of whether the proposal would harm an existing centre is separate, and above the floorspace threshold it is answered by a Retail Impact Assessment. And it is not the flood risk sequential test, which asks an entirely different question about zones of probability rather than about town centre vitality.

Failure is fatal in a way that impact findings are not. A proposal that fails the sequential test should be refused, without the balancing exercise that applies elsewhere.

Agreeing the area of search

Start from the catchment the proposal is designed to serve, then test it against how people actually travel.

For a food store, the area of search follows the convenience catchment, which is typically drive-time based and rarely more than a few minutes for a local store. For comparison retail, the catchment is larger and the relevant centres may include a higher order centre in the next district. For leisure uses the catchment can be wider again, because people will drive twenty minutes to a cinema and two minutes to a corner shop.

Three practical points save arguments later:

• Put the area of search to the authority in writing at pre-application stage, with the reasoning and a plan, and ask it to confirm or correct the boundary.
• Use the authority's own retail study where one exists. An area of search that contradicts the council's commissioned evidence base needs a stated reason.
• Say what you have excluded and why. An assessment that silently omits the neighbouring borough's town centre reads as an omission rather than a judgement.

Where the authority disagrees, the quickest route is usually to run the test twice, once on your boundary and once on theirs, and show that the conclusion holds either way.

In centre, edge of centre and out of centre

The categories carry defined meanings and the definitions matter because they decide the order of preference.

Connectivity for edge of centre sites is a matter of evidence. A site 250 metres from the primary shopping area across a dual carriageway with no signalised crossing is not well connected, and saying it is will cost you credibility on the rest of the assessment. Walk the route, photograph it, and give the actual walking distance rather than the straight line.

The defined boundaries come from the development plan proposals map, not from how the high street feels on a Saturday. Where the plan is old and the centre has shifted, that is an argument about the weight to give the plan rather than a licence to redraw the boundary yourself.

Flexibility and scalability of the proposal

National policy expects flexibility on format and scale. In practice that means you have to show you have properly considered a different configuration before concluding that no preferable site works.

Flexibility that carries weight:

• A smaller store footprint, with the trade-off in range stated.
• A two-storey format where the sequentially preferable site is constrained in area.
• Separate servicing arrangements, or servicing from the rear, where a centre site cannot take an on-site yard.
• Reduced car parking where a centre site is well served by public transport.

Flexibility that does not: changing the operator's business model, abandoning the format entirely, or accepting a unit so small it cannot trade. The Dundee reasoning protects you here, provided you have explained the operational requirement in terms a planning officer can test. State the minimum sales area, the minimum yard depth for the delivery vehicle, the floor-to-ceiling height, and why each is a requirement rather than a preference.

Be honest where the requirement is commercial rather than physical. An operator's preference for 120 car parking spaces is a preference. A yard that will not take an articulated vehicle is a constraint. Mixing the two is the fastest way to lose the argument.

Availability, suitability and viability

Each candidate site gets three questions, and the answers need evidence rather than assertion.

Availability asks whether the site is on the market or could reasonably become available within a reasonable period. A site in third party ownership with no evidence of willingness to sell is not available simply because it is vacant. Land registry title, marketing particulars, agent correspondence and planning history all help. Interim occupation complicates it, and the way meanwhile use affects land value can be relevant where a site is temporarily occupied but strategically available.

Suitability asks whether the site can physically and functionally accommodate the proposal, applying the flexibility discussed above. Constraints that count include area, shape, access, levels, ground conditions, heritage designations and existing occupation.

Viability asks whether development is realistically deliverable on the site. This is the limb most often handled badly, because a developer arguing that a town centre site is unviable is arguing against a position they would resist in any other context. Where you rely on it, use the same appraisal discipline you would apply elsewhere, and present it in the format described for a viability appraisal submission so that the figures can be interrogated.

Disaggregation and its limits

Disaggregation is the suggestion that a single proposal could be split across two or more preferable sites. It comes up most often where an out of centre scheme combines retail with other main town centre uses.

National guidance has consistently discouraged requiring applicants to break a proposal into separate parts to fit smaller sites, while still expecting flexibility on format and scale. The boundary between the two is the live battleground, and the current wording should be checked rather than taken from an older assessment.

Where a scheme does have separable components, deal with it head on. Say which elements are functionally linked, give the operational reason, and test the separable parts against preferable sites anyway. An assessment that refuses to engage with the question invites the authority to answer it for you.

Presenting the assessment

A sequential test should be readable in five minutes by someone who has never seen the site. The structure that works:

1. The area of search, with a plan and the reasoning behind the boundary.
2. A schedule of every site considered, with a plan reference, area, ownership, current use and sequential category.
3. A short paragraph per site covering availability, suitability and viability, with the conclusion stated.
4. A summary table of outcomes.
5. The flexibility narrative, explaining what was tested and what was rejected, with reasons.

The schedule is where credibility is won. Include the sites that are awkward for you and explain them, because an assessment that only lists convenient failures reads as advocacy. A Sequential Test (Retail) drafted to that structure can be reviewed quickly, and where the impact question also arises, an Economic Impact Assessment can carry the wider case for the scheme.

Browse the report types on PlanScope to see which retail and town centre documents your proposal is likely to need, then draft them to structure before the site search begins.

This is general guidance, not legal advice; check the current Framework and guidance wording and the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.