C G Fry v Secretary of State: Supreme Court limits scope of reserved matters conditions

Supreme Court clarifies planning authorities cannot impose additional conditions beyond outline permission terms when approving reserved matters.
The Supreme Court has delivered an important judgement clarifying the scope of local planning authorities' powers when dealing with reserved matters under outline planning permissions. In C G Fry & Son Limited v Secretary of State for Housing, Communities and Local Government [2025] UKSC 35, the Court allowed the appeal on the question of whether authorities can impose conditions that go beyond the terms of the original outline permission.
The case centred on a development site where outline planning permission had been granted subject to various conditions requiring subsequent approval. When the developer sought approval for reserved matters, the local planning authority and planning inspector attempted to impose additional requirements related to protecting a Ramsar site, relying on updated Natural England guidance and paragraph 181 of the National Planning Policy Framework.
Lord Reed, delivering the judgement, emphasised that the grant of planning permission—whether full or outline—creates legally binding rights under planning legislation that cannot be undermined by subsequent changes in government policy or scientific advice. These rights are not defeasible and provide developers with certainty that costs incurred in pursuing development will not be lost through regulatory change of position.
The Court articulated that outline planning permission, whilst conditional in nature, remains a form of planning permission that locks in the developer's right to proceed with development within the defined parameters. The conditions attached to such permissions delimit the extent of risk a developer assumes and must be interpreted objectively according to what a reasonable reader would understand them to mean within the context of the consent as a whole.
Crucially, the judgement established that planning authorities cannot use the reserved matters approval process to revisit matters of principle already determined at the outline stage. Authorities are bound by the conditions set out in the outline permission and must act within those terms when deciding whether to grant approval. Any condition requiring approval is confined to consideration of matters fairly related to that specific subject matter and does not import a general power to refuse approval for extraneous policy objectives.
The Court cited established authority, including Kingsway Investments (Kent) Ltd v Kent County Council, which held that planning authorities must act in good faith and cannot misuse their functions to achieve indirectly what would amount to a revocation or modification of permission without compensation. If substantial changes in planning context occur, the appropriate recourse is through formal revocation or modification procedures under section 107 of the Town and Country Planning Act 1990, which trigger compensation rights.
In this case, both the Council and inspector had improperly relied on updated NPPF policy and Natural England advice to potentially eliminate any viable development within the ambit of the granted outline permission. This exceeded their lawful powers under the planning legislation.
The judgement distinguished cases where planning authorities must consider how different conditions within a single permission interact coherently, but reaffirmed that conditions reserving particular matters cannot be used to refuse schemes for reasons unrelated to those specific matters. National policy and new scientific advice do not confer power to reopen settled planning permissions, unlike the position with European sites under the Habitats Regulations.
The Supreme Court dismissed the appeal on habitats regulation issues but allowed it concerning the scope of reserved matters approval, providing important clarity on the binding nature of outline planning permissions and the limits of planning authority discretion.