When two become one

Oliver Lawrence analyses a recent High Court judgment on adjacent developments and the need to provide an Environmental Statement.

When should two developments be treated as one for the purposes of the Environmental Impact Assessment Regulations 2017 (“the EIA Regulations”)? The existence or approval of other developments can determine whether an Environmental Statement is required of a planning application and what that Environmental Statement should contain. These are important questions which directly bear on the costs of an application and its chances of success. The High Court has recently clarified how other developments can affect the requirement to provide an Environmental Statement in R (Wingfield) v Canterbury City Council & HNC Developments LLP [2019] EWHC 1975 (Admin).

The facts

The claimant challenged the grant of outline planning permission by the council for a mixed use development of up to 370 dwellings. The main ground of challenge was that the council had failed to treat this development and a development on an adjacent site as a single project for the purposes of the EIA Regulations. The council had already granted outline planning permission for the adjacent development the previous year.

The law

Local planning authorities are prohibited from granting planning permission for development that is likely to have significant effects on the environment (“EIA development”) unless an EIA has been carried out in respect of that development. [1] Developers can request that an authority issue a screening opinion as to whether their proposed development is EIA development and the authority must take into account any relevant cumulation with existing or approved development at the screening stage [2].  Developers can then request that the authority issue a scoping opinion as to what the Environmental Statement must contain should an EIA be required. The EIA Regulations provide that an Environmental Statement must include a description of the likely significant effects of the development on the environment resulting from any relevant cumulation of effects with other existing and/or approved projects. [3] In this way the EIA Regulations address cumulative effects both at the screening stage and the scoping stage.

However, an assessment of the cumulative effects of two developments is generally a narrower exercise than an assessment of two developments as a single project. When viewed as one, two proposed developments can trigger the requirement for an EIA which would have been avoided had they been viewed individually. For this reason the courts have long been concerned to prevent developers from splitting a project into smaller components in order to avoid the requirement for an EIA – what is colloquially known as “salami-slicing”. Projects should be viewed as one if in reality they should properly be regarded as integral parts of an inevitably more substantial development. [4]

The judgment

The Court held that this question of whether one or more projects should be treated as a single project for the purposes of determining whether an Environmental Statement is required before granting permission is a matter of judgment for the competent authority, subject to a challenge on grounds of irrationality or other public law error. [5] That makes these decisions difficult to challenge either way.

The Court listed four relevant factors:

• Common ownership: where two sites are owned or promoted by the same person, that could indicate that they constitute a single project;
• Simultaneous determinations: where two applications are considered and determined by the same committee on the same day and subject to reports which cross refer to one another, that could indicate that they constitute a single project;
• Functional interdependence: where one part of a development cannot function without another, that could indicate that they constitute a single project;
• Stand-alone projects: where a development is justified on its own merits and is pursued independently of another development, that could indicate that it constitutes a single individual project that is not an integral part of a more substantial scheme.

The Court found that the two developments were not part of a single project after applying these factors to the facts of the case. Furthermore, there was no information before the council which ought reasonably to have triggered an assessment into the question whether the two sites were part of a single project.

The lessons

Developers are already required to consider cumulation with other development in their requests for a screening opinion [6]. Two projects should not be viewed as a single project just because they have a cumulative effect on the environment. Nonetheless, it is important for applicants to be aware that local planning authorities can treat their development as part of another with the consequence that the EIA requirement is more difficult to avoid.

It is worth noting that the Court made it clear that there is no legal requirement for local planning authorities to view two projects as one beyond the screening stage.  Once the scope of the project has been identified for the purposes of determining whether an EIA must be carried out, an assessment of cumulative effects is all that the law requires. [7]

The four Wingfield factors are worth remembering. Developers should consider the risk of an EIA requirement before acquiring multiple nearby sites or submitting separate applications at around the same time. Functional interdependence refers to the actual relationship between two projects and might be obvious in the case of a wind turbine and a grid connection or, more plainly, adjacent sections of a road. Whether two projects “stand alone” is a more hypothetical question: would the development be justified without the other? Overall, decisions of this nature can be easy to explain but difficult to predict.

Oliver Lawrence is a barrister at No5 Chambers.

[1] Reg.3

[2] Reg.5(4) and Sch.3 (1(b))

[3] Reg.18 (3(f)) and Sch.3 (5(e))

[4] R v Swale BC ex parte RSPB [1991] 1 PLR 6 at [16]

[5] [63] of the Judgment

[6]Reg. 6(4(a)) and Sch.3 (1(b))

[7] [72] of the Judgment