North Somerset District Council v Secretary of State: failing the flood sequential test is not the end of the story

Flood risk policy has a reputation, not entirely undeserved, for operating as a series of gates: pass the sequential test or your scheme dies at the first hurdle, pass the exception test or it dies at the second. North Somerset District Council v Secretary of State for Housing, Communities and Local Government [2026] EWHC 1430 (Admin) confirms that this gate based reading of the National Planning Policy Framework is wrong, and in doing so consolidates a line of authority that anyone advising on flood risk in planning appeals needs to have firmly in mind.

The case concerned outline permission for 190 homes at Rectory Farm in Yatton, North Somerset, on a site in Flood Zone 3a. The inspector found, as a matter of fact, that the scheme failed the sequential test because twelve sequentially preferable sites existed elsewhere. On the council's case, that should have been the end of the matter, full stop. Instead, the inspector went on to consider whether the development would be safe for its lifetime and whether its benefits outweighed the flood risk, concluded that they did, and allowed the appeal under the tilted balance in paragraph 11(d) of the NPPF.

The council's argument was that this amounted to applying the exception test by the back door, in a case where the exception test was never reached because the sequential test had already failed. Mrs Justice Jefford rejected this, and the reasoning matters because it closes off what might otherwise have looked like a plausible reading of paragraphs 177 to 179 of the Framework. The two limbs of the exception test, wider sustainability benefits and lifetime safety, do not become legally off limits simply because they also happen to feature in a test that was never formally engaged. They remain what they always were: material considerations capable of being weighed in the overall planning balance under section 38(6) of the 2004 Act. The judgement draws a sharp distinction between considering those factors as material considerations (permissible) and applying "the exception test" as a discrete analytical step with its own pass or fail outcome (not permissible once the sequential test has failed). On the facts, the inspector did the former, even though the substance of what he weighed overlapped heavily with the exception test's content.

This builds directly on Mead and Gladman Developments, both decisions of Holgate J and Lieven J respectively, which the judgement treats as establishing that a failed sequential test is a significant factor attracting substantial weight, but not an automatic veto. The real safeguard against the sequential test being rendered toothless, the judgement suggests, lies in the weight given to its failure rather than in treating it as an absolute bar. Here the inspector attached "significant weight" to the failure, alongside residual flood risk, and still concluded the benefits of housing delivery, affordable housing, biodiversity and open space outweighed it.

The judgement also offers a useful steer on irrationality challenges to flood safety findings. The council argued the scheme could not rationally be called safe for its lifetime given that an undefended scenario, factoring in sea level rise, would inundate the houses to over a metre. The judge accepted the inspector's characterisation of that scenario as a sensitivity check on a "worst worst case" basis, used to test the more realistic defended design event rather than to define it. Treating the most extreme conceivable flood event as the design event, the judgement notes, would make every coastal or riverside scheme undeliverable.

For those running flood risk arguments at inquiry, the practical takeaway is that a failed sequential test is best fought on the weight it should carry in the balance, supported by evidence on housing need and the scale of any shortfall against sequentially preferable sites, rather than argued as a standalone knockout blow that an inspector has no power to weigh against anything else.