235: Supreme Court rules on overlapping planning permissions for development site

The Supreme Court recently handed down its judgment in Hillside Parks Ltd v Snowdonia National Park Authority. The judgment is of importance for developers of large residential development projects.

The decision made was that the unimplemented parts of a planning permission for a large residential development, dating back to 1967, could no longer be implemented. Those elements had been superseded by more recent permissions granted at the same site since 1987.

Background

Planning permission was originally granted in 1967 for the construction of 401 homes on a large site in Snowdonia National Park, Wales. Over the following twenty years, further planning permissions were granted, some of which involved substantial departures from the development authorised by the original 1967 permission.

In 1987, the High Court ruled that these subsequent permissions were variations of the original 1967 permission, and that the development authorised by that permission could still be implemented. Further planning permissions were issued after 1987, most of which were described as ‘variations’ of the original 1967 permission.

In 2019, the current owner Hillside Parks sought to ascertain whether the scheme authorised by the original 1967 permission could still lawfully be completed. The High Court and Court of Appeal said no: the implementation of the post-1987 planning permissions now precluded implementation of the original permission.

There was disagreement in the industry regarding these judgments. However, most agreed that the Court of Appeal’s decision left important questions unanswered.

In particular, whether development already lawfully implemented over part of a scheme could be rendered unlawful by virtue of subsequent development carried out over the unimplemented part of the scheme pursuant to a newer permission.

Supreme Court judgment

The Supreme Court dismissed Hillside Park’s appeal. It said the lower courts had correctly ruled that the unimplemented parts of the original 1967 permission could no longer be implemented, having now been superseded by several more recent permissions.

This case had caused considerable concern for developers of large scale projects. This decision goes some way to ease concerns that failure to implement some parts of a project pursuant to a planning permission could make development already carried out unlawful. The Supreme Court have stated that is not the case.