The Supreme Court will next week (4 July) hear a significant case in relation to the effect of implementing later planning permissions for the same site.
At issue in Hillside Parks Ltd (Appellant) v Snowdonia National Park Authority (Respondent) is where there are successive planning permissions relating to the same site, and the later permissions are for changes to one part of a wider development approved in the original planning permission, is the effect of implementing the later permission(s) that the original permission is completely unimplementable? Or can the original permission still be implemented in relation to areas unaffected by the later permission(s)?
The background to the case - as set out on the Supreme Court's website - is that in 1967, Merioneth County Council granted planning permission for the development of 401 dwellings ("the 1967 Permission") on a site in Snowdonia National Park ("the Site"). Between 1967 and 1973, it made seven further grants of planning permission in respect of the Site, each of which departed from the scheme of development authorised by the 1967 Permission.
Gwynedd County Council became the relevant local planning authority in 1974. In 1987, it argued in proceedings brought in the High Court by Landmaster Investments Ltd, which owned the Site at that time, that the 1967 Permission had lapsed ("the 1987 proceedings"). The High Court rejected that argument, deciding that the development authorised by the 1967 Permission could still lawfully be completed at any time.
Snowdonia National Park Authority ("the Authority") became the relevant local planning authority in 1996. It made eight further grants of planning permission in respect of the Site between 1996 and 2011.
In 2019, Hillside Parks Ltd ("Hillside"), which now owns the Site, brought a claim against the Authority, in order to ascertain whether the scheme of development authorised by the 1967 Permission could still lawfully be completed. The Authority argued that it could not be, as development carried out pursuant to the additional permissions granted after 1967 was inconsistent with it. In particular, roads had been built in areas designated for houses, and houses had been built in areas designated for roads. This kind of argument was not made by Gwynedd County Council in the 1987 proceedings.
Nonetheless, the High Court and the Court of Appeal – in Hillside Parks Ltd v Snowdonia National Park Authority  EWCA Civ 1440 – allowed the Authority to raise the point and ultimately resolved it in the Authority’s favour.
Hillside appealed to the Supreme Court.
A panel comprising Lord Reed, Lord Briggs, Lord Sales, Lord Leggatt and Lady Rose will hear the case in the Supreme Court on 4 July 2022.
See also: Drop-in permissions: Hillside Parks heads for the Supreme Court - 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. (February 2022)