On 3rd November 2020, the Court of Appeal dismissed an appeal against the decision of the High Court in Hillside Parks Limited v Snowdonia National Park Authority [2020] EWCA Civ 1440 which considered the question of whether a planning permission for 401 houses..." />
  • Category: Opinions | November 10, 2020

  • On 3rd November 2020, the Court of Appeal dismissed an appeal against the decision of the High Court in Hillside Parks Limited v Snowdonia National Park Authority [2020] EWCA Civ 1440 which considered the question of whether a planning permission for 401 houses in Aberdyfi, granted and implemented in 1967, was capable of further implementation in light of various subsequent planning permissions granted.


    In 1988, Hillside had acquired a site with the benefit of a planning permission granted in 1967 for 401 dwellings. Following the 1967 permission being granted, Hillside’s predecessor had discovered that part of the site was an old quarry. This created issues for the development and so an additional eight overlapping planning permissions were sought and granted between 1967 and 1987 for a number of dwellings which were built as substantial variations to the masterplan attached to the 1967 permission.

    However, in 1985 the Authority asserted that the 1967 permission was not valid and had not been implemented and as such the 1967 permission was subject to proceedings in the High Court come 1987. The High Court held that the 1967 planning permission was lawfully granted and had been properly implemented. The eight additional permissions granted between 1967 and 1987 were considered to be ‘authorised modifications of the previously approved development’. Judge Drake in 1987 declared that the 1967 permission may lawfully be completed at any time in the future, notwithstanding there having then been some incompatible developments in accordance with subsequent permissions.

    Since 1987, further case-law had considered the legal approach to overlapping consents and there was a gap in works on the site until 1996 when another eight additional permissions were granted and subsequently implemented. These also overlapped with the 1967 masterplan. The Authority therefore took the view that it was impossible to implement the original permission given these now 16 planning permissions in total.

    The High Court

    The issue was tried before HHJ Keyser in the High Court in September 2019. Hillside sought a declaration from the High Court that the Authority was bound by the ruling of Drake J in 1987, that the permission could still be relied upon and that the “planning permission may be carried on to completion, save insofar as development has been or is carried out pursuant to subsequent planning permissions granted for alternative residential development”. The claim was rejected by HHJ Keyser, finding for the Authority. He held that the 1987 High Court judgement was not wrongly made but that “the development which has occurred since 1987 now renders the development granted by the 1967 permission a physical impossibility and that future development pursuant to that permission would no longer be lawful.”

    The Court of Appeal

    The Court of Appeal considered HHJ Keyser’s approach, finding that there was nothing inappropriate about how he dealt with the 1987 High Court ruling. Also, the Court of Appeal found that the Authority should not be prevented from raising the principle established in Pilkington v Secretary of State for the Environment [1973] 1 WLR 1527, even though this was not raised in the 1987 High Court case. The Pilkington principle established that a developer can apply for, and a local planning authority can determine, multiple planning permissions relating to the same site. It also established that, in the absence of any condition or planning obligation to render an earlier permission unimplementable, the relevant test for determining whether a later planning permission can be implemented where there are multiple extant permissions relating to the same site is whether, having implemented one permission, it remains physically possible to carry out the development authorised by a second permission.

    LJ Singh in the Court of Appeal rejected Hillside’s reliance on F. Lucas & Sons Ltd v Dorking and Horley Rural District Council (1966) 17 P&CR 111, to the effect that a planning permission grants permission for a number of independent acts each of which is separately permitted. Hillside argued that Lucas applied here as some of the planning permissions authorise a number of ‘separate acts of development’ as opposed to one single development scheme. Lucas was not followed by the High Court and was not followed by the Court of Appeal either, citing that the principles in Lucas would only ever apply in very limited circumstances.

    LJ Singh also found that Lucas was inconsistent with the line of authority more recently culminating in Sage v Secretary of State for the Environment [2003] UKHL 22, which established that a “holistic approach” should be taken to the impact of a subsequent planning for incompatible development and regard should be had to the totality of the operations which the grant of a planning permission originally contemplated would be carried out. LJ Singh stated as follows:

    “… I would accept the submission made by Mr Lewis on behalf of the Respondent that there have been significant legal developments since the decision of Drake J in 1987. In particular, the decision of the House of Lords in Sage has placed greater emphasis on the need for a planning permission to be construed as a whole. It has now become clearer than it was before 2003 that a planning permission needs to be implemented in full. A “holistic approach” is required.”

    The Court of Appeal confirmed the principle in Sage, but did not overrule Lucas. LJ Singh went on to say as follows:

    “It is conceivable that, on its proper construction, a particular planning permission does indeed grant permission for the development to take place in a series of independent acts, each of which is separately permitted by it. I would merely add that, in my respectful view, that is unlikely to be the correct construction of a typical modern planning permission for the development of a large estate such as a housing estate. Typically there would be not only many different residential units to be constructed in accordance with that scheme, there may well be other requirements concerning highways, landscaping, possibly even employment or educational uses, which are all stipulated as being an integral part of the overall scheme which is being permitted. I doubt very much in those circumstances whether a developer could lawfully “pick and choose” different parts of the development to be implemented.”

    The Court of Appeal ultimately concluded that HHJ Keyser was correct to reach the conclusion that it is no longer possible to implement the 1967 permission in the light of factual developments since the judgment of Drake J in 1987. The Court of Appeal left open an important question about the status of development already completed before subsequent, incompatible development is carried out and whether that was lawful of not.


    This case seems to have caused some confusion as to whether multi-phased planning permissions with “drop-in” permissions are effective. There are occasions where a development site is subject to more than one consent. The practical reality of development especially on large-scale projects is that circumstances change over time. For instance where outline planning permission has been granted for a large multi-phase development, a “drop-in” planning permission is often secured for a different form of development on part of the site and planning permission secured under section 73 for any necessary amendments to conditions attached to the original permission so as to ensure that if development is carried on part of the site under the drop-in permission rather than the original permission, there will be no breach of any conditions attached to the original permission.

    Attention needs to be noted of LJ Singh’s comments and whether he was extending the principle under Sage by stating that the development needed to be “implemented in full” so as to be seen as authorising a single operation. This does not seem to be a correct interpretation of what LJ Singh was intending, especially give the facts before him. I believe the Court of Appeal case is a useful reminder that the value of a site-wide planning permission can effectively be extinguished where the grant and initiation of subsequent planning permissions has rendered it impossible to complete the original development as planned. When drop-in permissions and section 73 permissions are used on an original consent, however, this aligns all consents and as such all consents can be implemented without being in breach of the original consent. As long as planning conditions are not breached and there is adequate assessment of the cumulative effects, then the drop in applications and section 73 applications are still, in my view, valid for modern day multi-phased sites. I do not believe developers “pick and choose” different parts of development to be implemented; the reality of modern day development means that changes arise due to politics, economics, design, infrastructure, viability etc and the need for changes can lawfully be accommodated via the drop-in/section 73 planning permission route. A good example of this is the Barking Riverside development were political changes meant that the DLR extension was not going to be delivered and a new Overground extension had to come forward instead. This meant the masterplan had to change and various new consents granted so as to re-open the land again for housing delivery. In Hillside, the High Court and the Court of Appeal seemed to be dealing with 16 planning consents, some which were incompatible with the original consent (I would think, given this is unclear from the judgment, that the new consents were not in accordance with the Pilkington principle so they did not co-exist with the original permission as amended pre 1987).

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