No Adastral New Town Ltd v Suffolk Coastal District Council & Anor

An environmental assessment for a development plan must form part of an integrated and continuing process. It should begin at an early stage, while policies and options remain capable of development, although the law does not require simultaneous publication of the plan and assessment at every stage. Reasonable alternatives may be progressively narrowed and discarded, provided that adequate reasons remain available to consultees. Under the Habitats regime, an appropriate assessment need not be undertaken at the beginning of plan preparation. It must be completed before the plan takes effect, and the authority must be satisfied that the plan, including mitigation, will not adversely affect site integrity. A strategic policy may lawfully be conditional upon a later assessment, with an early review providing flexibility for any resulting housing shortfall.

The claimant, a residents’ group, challenged the adoption of the Suffolk Coastal Core Strategy under section 113 of the Planning and Compulsory Purchase Act 2004. The challenge concerned policies allocating approximately 2,000 homes east of the A12 near Adastral Park and raised four grounds: failure to comply with the Strategic Environmental Assessment regime; failure to undertake an appropriate assessment under the Habitats regime at a sufficiently early stage; reliance on mitigation said to be uncertain; and alleged lack of deliverability.

The Core Strategy had been examined by an independent inspector, who found it sound subject to modifications, including a requirement for strategic open space or a country park and further appropriate assessment. The Council adopted the Strategy on 5 July 2013. The central issues were whether the earlier assessment process unlawfully failed to inform the selection and enlargement of the housing allocation, whether the mitigation was sufficiently certain, and whether the conditional policy was capable of being a sound and deliverable strategic policy.

1. Claim dismissed. The Council’s environmental assessment process contained an early flaw because the consultation exercises in 2006, 2007 and 2008 were not accompanied by a sustainability appraisal. The assessment should have developed alongside the emerging plan so that environmental effects could influence significant choices during plan preparation.
2. There was no absolute requirement for the plan and environmental report to be published simultaneously or for every stage to have a separate completed assessment. The process is flexible and fact-sensitive. Options may be progressively narrowed, but reasons for rejecting reasonable alternatives must remain available to consultees. Here, the later assessments considered the original alternatives, the increase to 2,000 homes and the relevant environmental effects. The flaw was therefore corrected before adoption.
3. Under the Habitats regime, there is no prescribed time or form for an appropriate assessment beyond the requirement that it precede the plan taking effect. There is no express requirement to assess alternative sites under that regime. An assessment at an early stage is good practice, but failure to undertake it at the beginning does not invalidate the plan where the eventual assessment does not show likely significant effects.
4. Natural England’s views as the appropriate nature conservation body required great weight. The Council and inspector were entitled to consider mitigation as part of the plan, including the proposed country park, strategic open space, visitor management and wardening. The evidence and consultation established sufficient certainty and deliverability for the plan stage.
5. A strategic policy may make development conditional upon a future appropriate assessment. It need not be based on an entirely failsafe position at adoption. The policy imposed a lawful limit on development if adverse effects could not be mitigated, and the Council’s commitment to an early review supplied flexibility for any housing shortfall.