The Curzon cases have settled how planning authorities and developers evaluate disputes over Appropriate Alternative Development (CAAD), establishing clear rules for future proceedings. Previously, confusion reigned over how to assess CAAD proposals, with some treating them like pre-application discussions or limiting reviews to height and basic design elements. The Supreme Court has now determined that assessments under section 17(5) of the Land Compensation Act 1961 must mirror the actual process of obtaining planning permission, though with expanded considerations.
Four landmark Curzon cases required tribunals to resolve conflicts between parties, often tied to valuation outcomes, by applying consistent principles. The rulings provide direct guidance for handling similar disputes. This discussion assumes readers are familiar with the CAAD framework, which is now evolving due to the Levelling Up and Regeneration Act 2023.
The central issue in CAAD disputes remains whether a proposed development had a realistic chance of approval if the original planning permission were revoked. Tribunals must evaluate this against current market conditions, applying the cancellation assumption. While the Supreme Court addressed this in Secretary of State for Transport v Curzon Park Limited [2023] UKSC 30, that judgment focused on a preliminary matter not directly relevant here.
One key lesson is that CAAD evaluations must go beyond theoretical analysis. They require examination of real-world planning factors, including local policies, site limitations, and the developer’s track record. The Curzon cases indicate tribunals will assess whether a proposal fits within the development plan and serves the same purpose as the original permission, without assuming identical results.
The rulings also emphasize that valuation disagreements in CAAD claims will increasingly depend on whether tribunals accept a developer’s ability to deliver a scheme that satisfies planning requirements. Past decisions suggest that broad claims about market demand or speculative advantages will hold less influence than documented proof of feasibility.
