Planning decisions in England are made within a statutory and policy framework, but case law also plays an important role in shaping how that framework is interpreted and applied. Decisions of the courts help to clarify legal principles, resolve ambiguities in legislation and policy, and guide how planning authorities and Inspectors should approach particular issues.

Understanding the role of case law is therefore an important part of understanding how planning decisions are taken in practice.

What is planning case law?

Planning case law refers to judgments of the courts, most commonly the High Court, Court of Appeal and Supreme Court, that consider points of law arising from planning decisions. These cases typically arise from legal challenges to planning permissions, refusals or appeal decisions, often through judicial review or statutory challenges.

Case law does not create planning policy. Instead, it interprets legislation, regulations and policy, clarifying how they should be understood and applied. In doing so, it can influence how decision-makers approach issues such as the meaning of policy wording, the weight to be given to material considerations, or the lawfulness of decision-making processes.

How case law influences planning decisions

Case law establishes legal principles that decision-makers are required to follow. For example, court judgments have clarified matters such as:

  • how planning policies should be read and interpreted
  • the extent to which decision-makers must explain their reasoning
  • the approach to assessing material considerations
  • the limits of discretion in applying policy
  • the circumstances in which errors of law may arise

These principles underpin the way officers' reports are written, how committees are advised, and how Inspectors structure appeal decisions.

Importantly, decision-makers are not expected to cite case law in every decision. Instead, the principles established by the courts are embedded into everyday practice through guidance, professional training and established decision-making conventions.

Weight and relevance

Not all case law carries the same relevance to every decision. Some cases establish broad principles of general application, while others turn on specific facts or particular policy wording. The relevance of a case depends on whether it addresses a legal issue that is materially similar to the issue being considered.

In practice, case law is most influential where there is uncertainty or dispute over interpretation, such as the meaning of a policy requirement, the lawfulness of a condition, or the correct approach to balancing competing considerations.

Role in appeals and challenges

Case law is particularly prominent in appeals and legal challenges. Inspectors frequently refer to established legal principles when explaining how they have approached policy interpretation or decision-making. Similarly, legal challenges focus on whether a decision-maker has correctly applied the law, rather than whether the planning judgement itself was “right” or “wrong”.

The courts do not re-make planning decisions. Their role is to consider whether a decision was reached lawfully, following the correct process and applying the law properly. Where an error of law is identified, a decision may be quashed and re-determined.

Practical implications for applicants

For applicants and developers, the influence of case law reinforces the importance of clear, well-reasoned submissions. Applications and appeals should address policy requirements directly, explain the planning balance clearly and avoid assumptions that are not supported by evidence or established interpretation.

An awareness of relevant case law can also help in identifying risk, shaping strategy and understanding how particular arguments are likely to be viewed by decision-makers.

Summary

Planning case law plays a supporting but important role in decision-taking. It does not replace policy or professional judgement, but it provides the legal framework within which planning decisions must be made. By clarifying how legislation and policy are interpreted, case law helps ensure consistency, fairness and lawfulness across the planning system.

Disclaimer
This article is provided for general information only and does not constitute planning advice. Planning matters are site-specific and subject to change. Professional advice should be sought before taking action in relation to any particular site or proposal.