James Burton provides an insightful heads up on a case which has raised questions about overlapping or ‘drop in’ permissions and has wide implications for the development industry, and which is now heading for the Supreme Court.
Readers may recall the decision of the Court of Appeal in Hillside Parks Ltd v Snowdonia National Park Authority  EWCA Civ 1440, discussed by Stephen Tromans QC in the December 2020 edition of the 39 Essex Chambers newsletter.
In very short form (please see Stephen’s article for the full synopsis), the convoluted facts begin with a 1967 grant of planning permission for a large application based on a “masterplan”, followed by subsequent grants of planning permission within the original permission boundary that were inconsistent with the masterplan. There was then litigation in the 1980s that saw Drake J declare, inter alia, that development under the original permission had been lawfully begun and that it could be completed. Then a 2017 announcement by the planning authority that the original permission could no longer be implemented as it could not be completed (due to development under the subsequent permissions). The developer, Hillside Parks Ltd, sought declarations that the authority was bound by the judgment of Drake J (by reason of res judicata/estoppel) and that it could, in fact, continue to build out under the original permission.
The claim was rejected at first instance and again in the Court of Appeal.
As regards the point of particular interest to planners, essentially concerned with what have tended to be termed “drop-in” permissions, the Court of Appeal relied upon Pilkington v Secretary of State for the Environment  1 WLR 1527 and Sage v Secretary of State  UKHL 22;  1 WLR 983, in particular the oft-cited words of Lord Hobhouse at , which flow from the “holistic” structure of planning law:
23. … if a building operation is not carried out, both externally and internally, fully in accordance with the permission, the whole operation is unlawful…
On that basis, and in accordance with the approach taken by Hickinbottom J (as he then was) in Singh v Secretary of State  EWHC 1621 (Admin), at [19-20], the Court of Appeal held that as the original permission could not be completed in accordance with the masterplan, no further development could be carried out under it. The Court of Appeal distinguished F. Lucas & Sons Ltd v Dorking and Horley Rural District Council (1966) 17 P & CR 111.
Hillside Parks Ltd has now been granted (limited) permission to appeal to the Supreme Court. Although limited, the grant of permission is understood to cover the point of keen planning interest: whether the original permission can be continued notwithstanding the conflict between the masterplan and the subsequent permissions and so the inability to build out in full in accordance with the original permission.
How far discussion will range in the Supreme Court cannot be known, let alone the Court’s ultimate judgment. However, the Supreme Court will no doubt consider Pilkington and the rule developed there, along with the words of Lord Hobhouse in Sage. As such, the result promises to be of considerable importance for “drop ins” as a matter of principle.
Query, though, whether it will be of similar practice importance. On any view Hillside involves issues that seem rather dated in terms of modern planning practice, and which modern planning practice would tend to avoid. Many of the key events took place in a very different planning world. That world can be compared and contrasted with (1) the present legislative provision for both non-material amendments and “minor” material “variation” permissions; (2) habitual insistence upon site-wide infrastructure as a condition of planning permission for larger schemes; and (3) the practice of phasing for larger schemes. In reality, would the modern planning system give rise to a situation such as that in Hillside?