Supreme Court considers the effect of development under successive permissions in Hillside Parks Ltd v Snowdonia National Park Authority  UKSC 30
02 Nov 2022
The case raises issues of importance in planning law about the relationship between successive grants of planning permission for development on the same land and, in particular, about the effect of implementing one planning permission on another planning permission relating to the same site. In its judgment, the Supreme Court has re-affirmed what is known as the Pilkington principle – that where development is carried out on land which is incompatible with an extant planning permission, that permission can no longer be relied on as authorising further development. However, the Supreme Court has clarified that development already carried out in accordance with an extant permission is not rendered unlawful merely because further development under the permission is no longer possible. The Supreme Court also indicated that the Pilkington principle is engaged only where there has been a material departure from the permitted scheme, which is a question of fact and degree.