High Court Decision in John Southwood v Buckinghamshire Council Clarifies Legal Principles in Planning Permission Interpretation & Lawful Development

Citation: [2024] EWHC 71 (Admin)
Judgment on


The High Court’s decision in “John Southwood v Buckinghamshire Council” addresses several key legal principles relating to the interpretation of planning permissions and the concept of lawful development under UK planning law. The case highlights the complexities involved in judicial review applications concerning planning decisions and underscores the court’s deference to the planning authorities’ expertise and judgment. This article analyzes the legal principles applied in the judgment and connects them to the relevant aspects of the case.

Key Facts

The case centers on a dispute concerning the lawfulness of an “As Built” building erected pursuant to a planning permission granted in 2010 by an Inspector for a storage building. The claimant, John Southwood, challenged the Buckinghamshire Council (previously Aylesbury Vale District Council) for two decisions made. After reviewing various contentions, the court’s decision primarily addresses the challenge to the council’s decision to grant a change of use from storage to residential, determining whether the “As Built” building conformed to the originally granted 2010 Storage Planning Permission.

Interpretation of Planning Permission

The court considered the ‘reasonable reader’ approach outlined in Hillside Parks Ltd v Snowdonia National Parks Authority and UBB Waste v Essex County Council for interpreting planning permissions. Applying this principle, the court found that the planning permission did not specifically require brick as the material for the building’s construction, contrary to the claimant’s assertion.

Material Departures from Planning Permission

Referring to sections 56 and 96A of the Town and Country Planning Act 1990, the court discussed what constitutes a material operation and the significance of material changes to a planning permission. The court drew upon Commercial Land and Green v Secretary of State for Communities and Local Government precedents, affirming the planning officer’s judgment that changes to the “As Built” Building did not constitute material changes that would require a new planning permission.

Lawful Implementation and Breach of Planning Control

The court reiterated the principles from Hart Aggregates Ltd v Hartlepool Borough Council and Meisels v Secretary of State for Housing Communities and Local Government regarding the lawfulness of commencing development and the significance of pre-commencement condition breaches. It concluded that the implementation of the 2010 permission through the construction of footings was lawful, and hence, the building could be considered an “existing building” for the purposes of policy C1.

Enforcement Action and Material Differences

The court differentiated between the concepts of ‘material differences’ and ‘enforcement action.’ Citing Hillside and Lever Finance Ltd v Westminster (City) London Borough Council, the court accepted the officer’s judgment that although there were differences in the As Built Building from the permitted development, these were not materially different so as to warrant enforcement action.


The court ultimately dismissed the application for judicial review, finding in favor of the defendant, Buckinghamshire Council. The judge held that the differences between the “As Built” Building and the planning permission were immaterial in appearance and function and did not render the building unlawful. Further, the planning officer’s judgment was deemed to be rational and acceptable, and thus, the council’s decision to grant change of use permission was lawful.


In “John Southwood v Buckinghamshire Council,” the court underscores the discretion afforded to planning authorities in interpreting planning permissions and assessing materiality concerning developments. It highlights the nuanced and fact-sensitive nature of these determinations and the courts’ deference to the planning officers’ expertise and judgment. The principles established and reinforced in this case continue to shape the landscape of planning law, affirming the established legal edifice guiding planning permissions, their implementation, and enforcement in the UK.

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