Introduction

The case of Brook Avenue Residents Against Development (BARAD) v Hanslip & Ors ([2022] EWCA Civ 983) revolves around the legality of a local planning authority's decision to grant planning permission for housing development near a European protected site in the Solent. The central issues addressed in this appeal are twofold: firstly, whether the local authority conducted an "appropriate assessment" under Regulation 63 of the Conservation of Habitats and Species Regulations 2017 as mandated by the Habitats Directive, and secondly, whether the authority adhered to its duty under Section 38(6) of the Planning and Compulsory Purchase Act 2004 to follow the development plan unless overridden by material considerations.

Summary of the Judgment

The England and Wales Court of Appeal dismissed BARAD's appeal against Fareham Borough Council's decision to grant planning permission for the development of eight detached houses. The appellant challenged the council's use of an average national occupancy rate of 2.4 persons per dwelling and the application of a 20% precautionary buffer in calculating the nitrogen budget, which are critical components in assessing the environmental impact of the development on the nearby Solent Special Protection Area (SPA).

The Court upheld the original decision, asserting that the council's methodology was sufficiently precautionary and in compliance with established legal principles. The use of average figures, combined with expert consultation and the precautionary buffer, was deemed lawful and did not constitute a Wednesbury error—a standard for judicial review concerning unreasonableness.

Analysis

Precedents Cited

The judgment extensively referenced key cases to cement its legal reasoning:

• Holohan v An Bord Pleanála [2019] PTSR 1054: Emphasized that determining whether a development affects the integrity of a site is a judgment for the competent authority, not the court.
• Waddenzee (Landelijke Vereniging tot Behoud van de Waddenzee v Staatssecretaris) [2005] 2 CMLR 31: Introduced the "precautionary principle" requiring high standards of investigation in environmental assessments.
• Coöperatie Mobilisation for the Environment UA, Vereniging Leefmilieu v College van Gedeputeerde Staten van Limburg (Dutch Nitrogen) [2019] Env LR 27: Clarified that national courts must thoroughly examine the scientific soundness of appropriate assessments.
• R. (on the application of Champion) v North Norfolk District Council [2015] UKSC 52; [2015] 1 WLR 3710: Reinforced that the court's role is supervisory, not substitutive, over competent authorities in environmental assessments.

These precedents collectively affirm that while courts oversee the legality of competent authorities' decisions, they do not replace the authorities' expertise in making evaluative judgments about environmental impacts.

Legal Reasoning

The court's legal reasoning focused on several critical points:

• Judicial Deference: Emphasized that courts should defer to the planning authority's expertise unless there's a clear error, adhering to the Wednesbury standard of unreasonableness.
• Appropriate Assessment: Affirmed that the council's use of the average occupancy rate and the 20% buffer, as outlined in Natural England's technical guidance, was lawful. The assessment was deemed sufficiently precautionary given the context and the absence of opposing concerns from Natural England.
• Precautionary Principle: Upheld the necessity of a precautionary approach but recognized that absolute certainty is unattainable. The council's method provided reasonable certainty to negate adverse effects on the site's integrity.
• Use of Average Figures: Determined that using average land use figures did not inherently violate the obligations under Regulation 63, especially since it was coupled with expert consultation and precautionary measures.

Impact

This judgment reinforces the authority of local planning bodies to apply standardized methodologies, such as average occupancy rates and precautionary buffers, in environmental assessments. It clarifies that adherence to expert guidance and the implementation of reasonable precautionary measures are sufficient to meet legal obligations, provided they are contextually justified and not demonstrably deficient.

Future cases involving environmental impact assessments will likely reference this judgment to support the validity of using standardized, expert-recommended methodologies, especially when tailored buffers and average figures are contextually appropriate and consulted with relevant conservation bodies.

Complex Concepts Simplified

• Appropriate Assessment: A process required under European law to evaluate whether a proposed development will significantly affect protected natural sites.
• Regulation 63 of the Habitats Regulations 2017: UK legislation implementing the EU Habitats Directive, mandating assessments to protect natural habitats.
• Precautionary Buffer: An additional margin applied to calculations to account for uncertainties, ensuring that environmental assessments remain protective even when precise data isn't available.
• Wednesbury Error: A legal standard that refers to decisions so unreasonable that no reasonable authority would ever consider imposing them.
• Section 38(6) of the Planning and Compulsory Purchase Act 2004: Stipulates that planning decisions must be made in accordance with the development plan unless material considerations dictate otherwise.

These simplifications help in understanding the legal framework within which this case was adjudicated, highlighting the balance between regulatory compliance and expert judgment.

Conclusion

The Court of Appeal's decision in BARAD v Hanslip & Ors underscores the legitimacy of local planning authorities in utilizing average occupancy rates and precautionary buffers within their environmental assessments. By adhering to expert guidance and implementing reasonable safety margins, authorities can fulfill their legal obligations without necessitating absolute precision.

This judgment holds significant weight for future environmental assessments, confirming that standardized, expert-informed approaches are lawful and effective, provided they are applied judiciously and contextually. It also serves as a reminder of the courts' restrained role in deferring to specialized administrative expertise unless manifestly unreasonable errors are present.