A high court judgment has effectively hollowed out the sequential test — the planning mechanism designed to be the final barrier preventing development on England's highest-risk floodplains. The ruling allows Persimmon Homes to build 190 homes on land classified as flood zone 3a in north Somerset, even though the planning inspector identified 12 alternative sites at lower flood risk. The court found the inspector was entitled to weigh the development's 'wider benefits' against the failed test. The sequential test exists for a single reason: to ensure homes get built on safer land when safer land is available. Persimmon failed it. The inspector found a dozen alternatives. The development went ahead anyway, because the court accepted that broader planning considerations — housing need, economic benefit — could override the test's verdict. This is not a marginal interpretation; it is a structural bypass. If wider benefits can always outweigh a failed sequential test, the test is no longer a test. The extraction mechanics are blunt. Persimmon captures the development profit from building on cheaper floodplain land. Existing homeowners surrounding the site absorb the risk. Sue Gardiner, whose living room overlooks the site, reports being refused by three major house insurers on the grounds of increased flood risk from the planned development. Without insurance, her home becomes unmortgageable. Richard Croucher faces the same arithmetic: a home intended to fund elderly care may become worthless. The costs are socialised; the profits are private. The ruling's national significance is not disputed by either side. Charles Banner KC, who represented Persimmon, called the decision 'hugely important.' His chambers described it as being of 'immense interest to the planning and development sector.' Tessa Munt, chair of the flooding APPG, called it 'a dangerous and nationally significant exploitation of planning loopholes.' The Environment Agency objected to the development on flood risk grounds. North Somerset council fought the application through its own legal challenge and lost. The political response is already mobilising. At a flood resilience conference this week, attendees agreed to campaign for a change in the law. Munt will now meet housing and planning minister Matthew Pennycook to request amendments to the national planning policy framework. The urgency is real: every week the ruling stands without legislative correction, it becomes available precedent for developers across England and Wales holding land in flood zones 3a and below. The deeper structural problem is the collision between housing targets and flood safety. England already builds one in nine new homes in areas of flood risk. The government needs housing volume. Developers need margins. Floodplain land is cheaper precisely because it is riskier. This ruling removes the friction that was supposed to prevent the obvious arbitrage: buy cheap risky land, build, sell, and leave the flood risk with the buyers and their neighbours. Flood Re — the joint government-insurance initiative — exists because the market already prices flood risk as uninsurable for many properties. Adding 190 homes to a flood zone 3a site works against the entire logic of that programme. The twenty-year trajectory is grimly predictable. Climate models project increasing flood frequency and severity across England. Every home built on a floodplain today becomes a future liability — for homeowners, insurers, local authorities, and central government when the bailouts arrive. The sequential test was the mechanism designed to prevent this. The high court just made it optional.
