Court Clarifies Role of Mandatory Material Considerations in Planning Decision-Making: Chala Alice Fiske v Test Valley Borough Council Judgement

Citation: [2023] EWCA Civ 1495
Judgment on


In the recent judgment of Chala Alice Fiske v Test Valley Borough Council [2023] EWCA Civ 1495, the Court of Appeal (Civil Division) was faced with the question of whether a local planning authority erred in law by granting planning permission for a substation development associated with an extant solar park permission. The core of the dispute revolved around whether the local authority should have considered the incompatibility between the granted planning permission for the solar park and the subsequent application for the substation as a “mandatory material consideration.” This article will dissect the decision, exploring the legal principles applied by the court and their implications for UK planning law.

Key Facts

The appellant, Chala Fiske, challenged the decision of the Test Valley Borough Council to grant planning permission for a 132kV substation within an existing solar park site at Woodington Farm. The council had previously granted permission for a solar park that included a 33kV substation to connect it to the national grid. The application for the 132kV substation was inconsistent with this earlier planning permission, creating an incompatibility that the appellant contended should have been considered a mandatory material consideration in the planning decision.

The Court of Appeal anchored its decision in several legal principles, key among them being the established law on material considerations in planning decisions, the incompatibility of planning permissions, and the statutory role of local planning authorities:

  1. Material Considerations in Planning Decisions: The court reiterated the principle that in planning decisions, authorities are obliged to consider ‘material considerations,’ with materiality often linked to issues that relate to the character and use of the land. However, not every consideration that may be relevant must be treated as material. Only issues that are expressly or implicitly required under statute or policy as ‘mandatory material considerations’—or are so ‘obviously material’ that omission to consider them would be irrational—command consideration as a matter of legal obligation.

  2. Incompatibility of Planning Permissions: The court drew heavily on prior judgments, specifically the seminal case of Pilkington v Secretary of State for the Environment [1973] 1 W.L.R. 1527 and the reaffirmation of its principles in Hillside Parks Ltd. v Snowdonia National Park Authority [2022] UKSC 30. It clarified that multiple applications and the granting of planning permissions for different developments on the same site, even if incompatible, are not prohibited by the planning system.

  3. Duty of Local Planning Authorities: It was stated that local planning authorities need not predict or anticipate how applicants will reconcile granted but conflicting planning permissions. Their role is not to assume that the developer will act unlawfully or speculate on how an incompatibility will be addressed. Enforcement powers are available should a breach of planning control occur.


The court found that the incompatibility between the original solar park permission and the new substation application was not an ‘obviously material’ consideration that the council was mandated by law to consider, thus upholding the lawful granting of the 132kV substation permission. It was concluded that it is not uncommon for large developments to require modifications during planning and implementation, and such adaptability is built into the planning system. The court also found no procedural unfairness in the handling of the case by the lower court judge.


The judgment in Chala Alice Fiske v Test Valley Borough Council [2023] EWCA Civ 1495 reaffirms the legal principles pertinent to material considerations and the handling of incompatible planning permissions. The decision entrenches the council’s discretionary power in determining planning applications while delineating the boundaries of mandatory material considerations. It emphasizes that local planning authorities are not required to resolve potential future conflicts arising from the granting of permission for incompatible developments, leaving such matters within the developer’s remit to address lawfully within the flexible framework of the planning system.

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