Crest Nicholson Operations Limited v Secretary of State for Housing, Communities and Local Government & Anor

In a statutory planning review, the court’s role is supervisory. It must not substitute its planning judgment for that of the decision-maker.

Under regulation 63 of the Conservation of Habitats and Species Regulations 2017, permission may be granted only where the competent authority has ascertained that the project will not adversely affect site integrity. The appropriate assessment must be sufficiently complete, precise and definitive to remove reasonable scientific doubt. A decision-maker may assume that other regulatory regimes will operate effectively, but that is a rebuttable presumption and does not provide the required certainty where the evidence leaves unresolved what protective action will be taken, how and when.

The claimant developer challenged, under section 288 of the Town and Country Planning Act 1990, the Secretary of State’s approval of reserved matters for 280 dwellings at Kilnwood Vale, subject to a condition preventing occupation until water neutrality mitigation had been secured.

The development was within the Sussex North Water Resource Zone, where groundwater abstraction at Hardham could not be excluded as contributing to harm to the Arun Valley protected sites. The claimant argued that reliance could be placed on future action by the Environment Agency and Southern Water, and that the possibility of alternative water supplies excluded reliance on imperative reasons of overriding public interest. The central questions were whether the decision-maker had lawfully applied regulations 9, 63 and 64 of the Conservation of Habitats and Species Regulations 2017, and whether the evidence provided reasonable certainty of no adverse effect.

1. The claim was dismissed. The Inspector and Secretary of State had not erred in law or acted irrationally. Their conclusion that the proposal could not be approved without Condition 6 was a lawful exercise of planning judgment.
2. Under regulation 63(5) of the Conservation of Habitats and Species Regulations 2017, the competent authority had to ascertain that the development would not adversely affect the integrity of the Arun Valley sites. The precautionary principle applied. Absolute certainty was unnecessary, but the appropriate assessment had to be based on sufficiently rigorous scientific evidence and contain complete, precise and definitive findings capable of removing reasonable scientific doubt.
3. The decision-maker was entitled to take account of other regulatory regimes and to assume that they would operate effectively. That was a rebuttable presumption, not a legal obligation. The decision whether the evidence justified relying on those regimes was an evaluative public law judgment subject to ordinary Wednesbury review. The existence of other controls did not remove the obligation to undertake the required assessment.
4. Regulation 9(3) imposed a general duty to have regard to the requirements of the Directives when exercising functions. Regulation 63 imposed a specific and more stringent duty when deciding whether to authorise a plan or project. Harris did not erase that distinction. Its reasoning depended on the Environment Agency’s particular role in that case, whereas this case involved overlapping competent authorities, including Southern Water and the planning decision-maker.
5. The Inspector was entitled to find that the ongoing scientific investigation, the uncertainty surrounding alternative supplies, and the unspecified future actions of the Environment Agency and Southern Water as to how and when protective measures would be taken did not provide reasonable certainty of no adverse effect. Voluntary abstraction minimisation was relevant but temporary and did not itself secure the necessary protection.
6. Ground 1 failed because the reserved matters decision was not based on IROPI. The Inspector correctly stated that regulation 64 could provide a route for a plan to proceed after a negative assessment where its statutory tests were met, but recommended that the Secretary of State should not rely on IROPI for this proposal. Ground 2 also failed. The statutory review claim was dismissed.

First-instance statutory review under section 288 of the Town and Country Planning Act 1990. The judgment records the Secretary of State’s decision dated 25 October 2024 and dismisses the challenge to it.