Overlapping planning permissions: which one is valid?

The High Court has recently revisited the principles for determining the validity of overlapping consents. Gary Soloman and Alex Minhinick highlight the key points for landowners, developers and local authorities.

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. This can lead to multiple consents being granted on the same site and confusion over which apply. Courts have scrutinised circumstances where there are overlapping consents like this and established principles to determine which consents are valid.

A recent case in the High Court considered just this issue. In Hillside Parks Ltd v Snowdonia National Park Authority [2019] EWHC 2587 (QB), the developer of a large housing estate (Hillside) was seeking to rely on a permission which was granted in 1967 to complete development on a site in Aberdyfi.

The High Court found in favour of the respondent Authority (Snowdonia National Park Authority) who sought to prevent Hillside from completing development under the 1967 permission.

In coming to its decision, the court considered the principles set out in previous cases and examined, in the case of the Hillside site, whether the events which had occurred since the 1967 permission now:

• preclude the lawful completion of the development; or
• represent ‘a number of separate acts of development’?

The Facts: 1967 to 1987

Hillside acquired a site with the benefit of planning permission granted in 1967 for 401 dwellings.

In 1987, the year before they acquired the land, the 1967 permission was subject to proceedings in the High Court.

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 additional permissions were sought and granted (eight in total) for a number of dwellings which were built as substantial variations to the masterplan attached to the 1967 permission. In effect the eight additional permissions overlapped the 1967 permission.

In 1985 the local planning authority then asserted that the 1967 permission was not valid and had not been implemented. However, the court in the 1987 case declared 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’.

The Facts: 1987 onwards

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.

At the start of the 2019 proceedings, the 1967 permission had been supplemented by a total of 16 additional permissions for dwellings at various locations within the larger site. Only 41 dwellings had been completed.

Which legal principles applied? Separate acts of development

Hillside argued that Lucas & Sons Ltd v Dorking and Horley Rural District Council ([1964] 17 P&RC 111) applied to their site. The rationale in Lucas was that some permissions, on their true construction, authorise a number of ‘separate acts of development’ as opposed to one single development scheme.

In Lucas, the separate acts of development pertained to the construction of dwellinghouses (each one being a separate act). The judge ruled that the construction of these was lawful. It was done so in accordance with the planned development as granted despite the fact that other dwellinghouses, constructed under subsequent permissions on the same plot, contradicted the original permission.

The judge did not accept the principles in Lucas applied to the Aberdyfi site and cautioned that they would only ever apply in very limited circumstances.

Overlapping consents can preclude development

The courts have looked at the problem of overlapping consents in several scenarios, one of which considered development on a one acre site (in Pilkington v Secretary of State for the Environment [1973] 1 WLR 1527). The site was first granted permission for one dwellinghouse at the centre of the site.  The site was then granted a second permission for one dwellinghouse built in the corner of the site. The building works begin in the centre of the site – thus implementing the first permission.  Then a dwellinghouse was built in the corner of the site under the second permission. Even though the first permission was implemented, development under it cannot then be lawfully completed as it would result in two dwellinghouses on the site which was not within the permission.

Conclusions of the court

The court distinguished between the pre-1987 additional permissions and those granted later on, stating that the earlier permissions resulted in only minor alterations to the scheme and as such could be considered ‘authorised modifications’.

Conversely, the court found that the development which had taken place since 1996 under the eight additional permissions was materially inconsistent with the master plan of the 1967 permission.  For example, an estate road had been built in a location which cut across a row of terraced houses included on the 1967 master plan. The court established that it would be impossible to complete the development fully in accordance with the 1967 permission.  Therefore, no further development could be carried out under the 1967 permission. 

Key takeaways

This is a cautionary message to developers, especially on development sites with a convoluted planning history. Ascertaining which consents are valid and which can be completed is important in determining land values.

Clarity can be achieved through the use of outline permissions followed by the detail contained in reserved matters approvals; requesting non-material amendments to a permission; or by applying to vary a condition on a permission. The general rule that you must implement a planning permission as it was originally granted (or risk losing its benefit) still stands, and only in limited circumstances can this be circumvented.

Gary Soloman is a partner and Alex Minhinick is a Senior Associate at Burges Salmon. Gary can be contacted on 0117 902 2791 or This email address is being protected from spambots. You need JavaScript enabled to view it., while Alex can be reached on 0117 307 6874 or This email address is being protected from spambots. You need JavaScript enabled to view it..