The Curzon cases provide practical lessons on assessing planning prospects, development proposals, and evidential requirements in CAAD disputes. Historically, practitioners faced uncertainty in evaluating schemes proposed as Appropriate Alternative Development. Analogies have been drawn to the “pre-application stage” (Pro Investments v Hounslow LBC [2019] UKUT 319, at 112), and references made to ‘height and basic formation’ (Bashir v London Borough of Newham [2024] UKUT 00146 (LC) at 111-116), reflecting the challenges in defining the scope of such developments.

This article is in two parts: Part 1 examines the key elements of the CAAD system as considered in the Curzon Cases, the major changes introduced by the Levelling Up and Regeneration Act 2023 (LURA), and the real role and advantages of CAADs under each system. Part 2 focuses on the guidance derived from the Curzon Cases regarding the application of the fundamental test for Appropriate Alternative Development.

The Supreme Court clarified that the role under s17(5) LCA 1961 mirrors the process for granting planning permission, albeit with broader strokes (SST v Curzon Park Ltd [2023] UKSC 30 at 87, 89). This involves assessing whether a development could reasonably expect planning permission, considering market circumstances and the cancellation assumption.

These cases prompted the Tribunal to examine dispute resolution more closely, driven by valuation implications. The decisions offer guidance for similar cases, particularly as the CAAD system evolves under the Levelling Up and Regeneration Act 2023.

In Secretary of State for Transport v Curzon Park Limited [2023] UKSC 30, the Supreme Court provided guidance on this assumption, focusing on circumstances known to the market. For individuals handling CAAD disputes, the Curzon cases provide useful lessons on the system’s practical use and ongoing changes, particularly in light of LURA’s reforms and the evolving legal environment.