Canterbury City Council v Secretary of State for Housing, Communities and Local Government

Factual and Procedural Background

This judgment addresses claims in two separate cases involving planning permission decisions related to proposed developments and their environmental impacts under the Habitats Regulations 2017, which implement the Habitats Directive 92/43/EEC. Both cases concern errors of law regarding whether an Appropriate Assessment was required for effects on European designated sites.

The first case relates to a large mixed-use development proposed by an Interested Party on a site known as Strode Farm, Herne Bay, within the jurisdiction of Canterbury City Council (the Claimant). The planning application included demolition, new dwellings, and infrastructure improvements. The Claimant failed to determine the application in time, leading to the Secretary of State for Housing, Communities and Local Government (the Defendant) taking over the decision. The development raised issues concerning impacts on European sites, highway infrastructure provision, and planning obligations.

The second case concerns a proposal at Broden Stables near the village of Crondall. The development proposed demolishing existing equestrian facilities and erecting 30 residential dwellings. Crondall Parish Council (the Claimant) objected to the application on grounds including conflict with countryside protection policies and adequacy of mitigation for impacts on the Thames Basin Heaths Special Protection Area (SPA). The local planning authority (the Interested Party) refused permission, and the appellant (Second Defendant) appealed.

Both appeals proceeded through public inquiries and decision letters, with extensive consideration of environmental impacts, planning policy, and mitigation measures. Both cases involved challenges to the Secretary of State's or Inspector's decisions on grounds including failure to undertake an Appropriate Assessment under the Habitats Regulations.

Legal Issues Presented

1. Whether the Secretary of State erred in law by failing to carry out an Appropriate Assessment of the effects of the proposed developments on the integrity of European Sites prior to granting planning permission, contrary to regulation 63 of the Habitats Regulations 2017 and Article 6(3) of the Habitats Directive.
2. Whether the decisions were irrational or unlawful for granting planning permission without enforceable mechanisms to secure necessary infrastructure, particularly highway improvements in the Canterbury case.
3. Whether the Inspector in the Crondall case erred in his interpretation and application of local development plan policies, including policy RUR2 relating to development in the countryside, and the weight to be accorded to emerging local plans.
4. Whether the mitigation strategies (including SANGs and SAMM contributions) relied upon were adequate to prevent likely significant effects on European sites, and whether the failure to undertake an Appropriate Assessment affected the validity of the decisions.
5. The proper approach to taking into account mitigation measures at the screening stage of Habitats Regulations Assessment in light of recent Court of Justice of the European Union (CJEU) authority, particularly the People Over Wind judgment.
6. The exercise of the court's discretion under section 288 of the Town and Country Planning Act 1990 whether to quash decisions affected by errors of law, including consideration of whether the decisions would inevitably have been the same absent the error.

Arguments of the Parties

Claimants' Arguments

• In the Canterbury case, the Claimant contended that the failure to carry out an Appropriate Assessment was a significant error of law that could not be cured by the court and that the decision was irrational for granting permission without a mechanism to secure full funding for essential highway infrastructure (Kent BRIS).
• In the Crondall case, the Claimant argued that the Inspector misunderstood the position of the parties and took into account irrelevant considerations regarding policy RUR2, failed to give adequate reasons for discounting earlier decisions, and erred in the weight given to the emerging Local Plan policies.
• They further submitted that the mitigation measures (SANGs and SAMM) were not proven effective in this case, noting the distance between the development and the nearest SANG and concerns from local objections about accessibility and adequacy.
• The Claimants contended that the failure to undertake an Appropriate Assessment and the application of the tilted balance in the planning judgment were errors of law requiring quashing of the decisions.
• They submitted that the court could not be certain that the decisions would have been the same absent the legal errors.

Defendant and Interested Parties' Arguments

• The Defendant conceded the error of law in failing to carry out an Appropriate Assessment in both cases but contended that the decisions would inevitably have been the same if the assessments had been properly undertaken, justifying the exercise of discretion not to quash the decisions in the Canterbury case.
• They argued that the planning judgments, including the weighing of risks regarding highway infrastructure funding in the Canterbury case, were rational and lawful exercises of discretion.
• The Defendant and Interested Parties submitted that the mitigation strategies (SANGs and SAMM) were well-established, effective, and based on a strategic partnership approach, supported by Natural England and extensive consultation, thus adequately addressing impacts on European sites.
• They acknowledged that recent CJEU authority (People Over Wind) required disregarding mitigation measures at the screening stage but submitted that this did not alter the substantive outcome in these cases.
• Regarding policy interpretation in the Crondall case, they contended the Inspector properly applied planning policy and gave appropriate weight to emerging plans given their stage of preparation.
• They maintained that the Claimants were aware of and had opportunity to address relevant evidence and submissions during the appeal processes.

Table of Precedents Cited

Court's Reasoning and Analysis

The court considered the admitted error of law in both cases arising from failure to undertake an Appropriate Assessment as required by the Habitats Regulations and the Habitats Directive, in light of the CJEU’s People Over Wind decision. The court reviewed the detailed factual and procedural context of each case, including the environmental information, consultation responses, and planning policies.

In the Canterbury case, the court found that the extensive environmental information and consultation, including the Habitats Regulations Assessment Screening Statement and Environmental Impact Assessment, had in substance addressed the issues required in an Appropriate Assessment. The mitigation measures, including the Strategic Access Mitigation and Monitoring Plan (SAMM), were accepted by Natural England and undisputed by parties. The court was satisfied that no reasonable scientific doubt remained as to the absence of adverse effects on European sites, particularly the Thanet Coast and Sandwich Bay SPA/Ramsar.

Regarding the planning judgment in Canterbury, the court held that the Defendant's approach to the timing and funding of highway infrastructure, including the Kent BRIS, was a rational exercise of planning judgment. The Defendant properly weighed the risks and benefits, including the absence of an enforceable mechanism securing full funding, and this did not amount to irrationality.

In the Crondall case, the court found that the Inspector’s interpretation and application of local plan policies, including policy RUR2, was supported by reasons and consistent with relevant case law. The Inspector gave appropriate weight to emerging plans given their stage of preparation.

However, in Crondall, the court found that there remained unresolved concerns regarding the adequacy and effectiveness of the mitigation strategy (SANGs and SAMM) to prevent likely significant effects on the Thames Basin Heaths SPA. Unlike in Canterbury, these concerns were not uncontroversial or fully addressed in the decision-making process, and the absence of an Appropriate Assessment was therefore a material procedural defect.

The court applied established principles governing whether to quash decisions affected by errors of law. It emphasized that the court must be satisfied that the decision would necessarily have been the same absent the error. In Canterbury, this test was met; in Crondall, it was not.

Accordingly, the court concluded that the Canterbury decision should not be quashed despite the error, whereas the Crondall decision must be quashed because the error was material and there was no certainty the decision would have been the same otherwise.

Holding and Implications

The court held as follows:

In the Canterbury case, the court dismissed the challenge and declined to quash the Secretary of State's decision granting planning permission, concluding that despite the admitted error of law, the decision would inevitably have been the same.

In the Crondall case, the court quashed the Secretary of State's decision granting planning permission due to the failure to undertake an Appropriate Assessment and the unresolved concerns about mitigation adequacy, concluding that the error was material and the outcome uncertain.

The direct effect of this ruling is that the Canterbury development permission remains valid, while the Crondall permission is set aside and must be reconsidered with proper compliance with the Habitats Regulations.

No new precedent was established beyond the application of existing principles regarding Appropriate Assessment, planning judgment, and the exercise of discretion in quashing decisions affected by procedural errors under environmental law.