Decisions, Decisions: Hillside in the High Court and Flood Risk in the Court of Appeal
Yesterday was a good day for Planning Court enthusiasts. It provided us with two fascinating judgments from the Royal Courts of Justice. Namely:
- Dennis, R (On the Application Of) v London Borough of Southwark  EWHC 57 (Admin); and
- Substation Action Save East Suffolk Ltd, R (On the Application Of) v Secretary of State for Energy Security and Net Zero  EWCA Civ 12
Dennis is the first High Court case to grapple with the practical implications of the Supreme Court's decision in Hillside.
Substation Action is a fascinating and important decision about the need for a sequential test for sites where surface water flooding issues may be present.
Both cases are important and worth reading in full, but in case you don't have the time or the energy at the moment,* I have attempted to summarise them.
Dennis is a decision that I have been tracking for some time. I first stumbled across it when writing my paper for the Joint Planning Law Conference in Oxford last October. ** At the time, I described the case as follows:
"In July, permission was granted on the papers for a judicial review challenge to a decision by Southwark LBC to approve a s.96A application that added the word “severable” into the description of development for a phased, outline planning permission (OPP) relating to the Aylesbury Estate in London.
The officer’s report for the s.96A application considered the potential impacts of the change as follows:
“13. In the context of Aylesbury the main issue for consideration would be if the OPP could still be fulfilled in the context of a ‘drop in’ application on, such as that on Phase 2B (22/AP/2226), being approved. The original permission in Hillside was a detailed planning permission where the development form was specifically set out in the plans approved as part of that original planning permission. The subsequent implementation of the later permissions, led to development being constructed in positions where it made the earlier development approved by the original planning permission physically incapable of being carried out.
14. Unlike the case referenced in the Hillside judgement, the OPP is a phased development, approved in outline only. The approval of a standalone application on Phase 2B, outside the parameters of the OPP would not render the remainder of the OPP undeliverable. In essence Phase 2B can be severed from the OPP and this would only take place at the point at whichany permission issued for a discrete application on Phase 2B is implemented. The building extents for Plot 2C are maximum extents and as such any reserved matters application can be designed to take account of Phase 2B whilst still remaining entirely within the approved parameters of the OPP.
15. Prior to the Phase 2B drop in application being presented to planning committee, the applicant confirmed that they would submit a non-material amendment (S96A) application in order to formalise the severable nature of the OPP and this would be submitted and completed prior to issuing any consent on this site. Officers have no objection to this amendment as it would not alter the terms of the OPP and would confirm the ability to sever phases to deliver them independent from the OPP in order to better reflect the changing policy landscape since the OPP was first approved.
16. The proposed addition of the word ‘severable’ to the development description of the OPP is considered to be non-material in nature. It is the first change to the proposal description, so there is no cumulative impact to consider. The EIA considered the redevelopment as a phased redevelopment; the amendment to the proposal description would not materially affect the assumptions within the ES nor the mitigation secured.”
The claimant is arguing that it was irrational for the Council to conclude that this change to the description of development was non-material. The claimant’s argument can be summarised as follows:
- the fact that a permission is phased and granted in outline does not automatically render it severable.
- if the permission was not already severable, then the decision to sever is a material one—as it has the potential to significantly alter the final form of the development."
We now have the Judgment and Mr Justice Holgate sided firmly with the claimant. The key paragraphs are paras 119 and 120, which read as follows:
"119. Accordingly, I am in no doubt that on a true construction the OPP was not severable prior to the s.96A amendment. It was a single planning permission with provisions for phasing. To the extent that the amendment made on 28 March 2023 severed the OPP, it had the effect of disapplying the Pilkington principle, i.e. it made it unnecessary to apply the physical impossibility test to a future "material" departure from the development authorised by the grant of the OPP. It therefore significantly enlarged the bundle of rights granted by that permission. In these circumstances, I agree with the parties that it must follow that this was a "material" amendment of the OPP for the purposes of s.96A of the TCPA 1990. Accordingly, Southwark's decision dated 28 March 2023 was ultra vires that provision.
120. On that basis the claim must be allowed. But I would add that I have strong reservations in any event about the legality of an amendment to a planning permission which simply inserts language as uncertain as the bare term "severable". There was nothing to indicate the extent to which the OPP was purportedly severed. For a large-scale development it would have been possible to conceive of many different alternatives."
As such, we now have judicial confirmation that:
- Hillside both can and does apply to phased, outline, planning permissions; and that
- Retrospectively severing a consent is likely to be considered material.
In an ideal world, I would have preferred more analysis on the materiality issue and further expansion on para. 120, but nonetheless, this is the first judicial guidance that we have on how Hillside is likely to be applied in practice.
If anyone has any information on whether Southwark is likely to appeal, I would love to hear it!
Whilst this decision appears to close the door on the use of s.96A to retrospectively sever a planning permission - it should be remembered that the same ‘materiality’ issues do not apply to s.73 applications - which would also by necessity include greater information on the extent and nature of the severability envisaged, as you would need to include them in the wording of and justification for your varied phasing conditions.
For more on my thoughts on this, please do check out my JPLC paper (or give me a call…)
This case centres on the proper interpretation of paragraphs 159 to 167 of the 2021 version of the NPPF, which dealt with flood risk, and related sections of the PPG. It also deals with the correct approach to assessing cumulative impacts.
I thoroughly recommend reading the decision in full. That said, this post is getting quite long*!, so I am going to simply leave you with the conclusions:
"60 The relevant provisions of EN-1, the Framework and the PPG do not require an applicant for development consent to demonstrate that whenever there is a risk of flooding from surface water there are no other sites reasonably available where the proposed development could be located in an area of lower surface water flood risk. The risks of flooding from surface water are to be taken into account when deciding whether to grant development consent under section 104 of the 2008 Act. The way in which account is to be taken of that risk raises issues of planning judgment in the application of the relevant provisions of the policies. The judge was correct in her interpretation of the policy and in finding that there was no irrationality or other public law error in the way in which the first respondent dealt with this issue when granting development consent. The effects of other potential projects (which were not projects forming part of the developments forming the subject matter of the application for development consent) did not have to be the subject of a cumulative impact assessment before development consent was granted in the present case. The first respondent was entitled to defer consideration of the effects of the other projects as there was insufficient information available to make an assessment. Such information as was
available on the likely effects of other potential projects was not relevant to the
assessment of the significant effects of the projects forming part of the applications for development consent in the present case. I would therefore dismiss this appeal."
Whilst this decision considered the 2021 version of the NPPF, the latest iteration is substantially the same on flood risk.
The decision also considers the pre-2022 Flood Risk PPG.
In short, however, the Court of Appeal has concluded that the NPPF does not state that whenever there is a risk of flooding from surface water, an application must demonstrate there are no other sites reasonably available in an area of lower surface water flood risk.
*January is not known for being the most energetic of months….
*! and I am also pretty sure that this will be picked up in the environmental updates
Accordingly, I am in no doubt that on a true construction the OPP was not severable prior to the s.96A amendment. It was a single planning permission with provisions for phasing. To the extent that the amendment made on 28 March 2023 severed the OPP, it had the effect of disapplying the Pilkington principle, i.e. it made it unnecessary to apply the physical impossibility test to a future "material" departure from the development authorised by the grant of the OPP. It therefore significantly enlarged the bundle of rights granted by that permission. In these circumstances, I agree with the parties that it must follow that this was a "material" amendment of the OPP for the purposes of s.96A of the TCPA 1990. Accordingly, Southwark's decision dated 28 March 2023 was ultra vires that provision.”