London borough defeats High Court challenge to basement policy

The Royal Borough of Kensington & Chelsea has fought off a High Court challenge to its revised basement policy.

The claimants in Lisle-Mainwaring & Anor v Royal Borough of Kensington and Chelsea [2015] EWHC 2105 (Admin) (23 July 2015) were Zipporah Lisle-Mainwaring, the freehold owner of a house in the borough who wants to build a basement, and Force Foundations (Basement Force), a specialist in the design and construction of basements which believes the new policy will restrict their business.

They applied under s. 113 of the Planning and Compulsory Purchase Act 2004 to quash the council’s adoption of a revision to its development plan, the Basements Planning Policy (BPP).

Adopted in January 2015, the BPP requires – amongst other things – all basement development to:

  • not exceed a maximum of 50% of each garden or open part of the site. “The unaffected garden must be in a single area and where relevant should form a continuous area with other neighbouring gardens. Exceptions may be made on large sites”;
  • not comprise more than one storey. Again, exceptions may be made on large sites;
  • not involve excavation underneath a listed building (including vaults).

The claimants challenged the policy on two grounds. The first was based on a claim that the council and the planning inspector had failed to take into account a material consideration, “namely the permitted development rights [PDRs] for basement development, and the risk of greater reliance on them if the BPP were adopted, without the benefit of any planning control over construction noise and loss of amenity”.

The claimants highlighted how the council did not intend to make an Article 4 direction before its adoption of the policy. However, shortly after adoption, it had made a borough-wide direction removing those PDRs.

Mrs Justice Lang rejected this ground, saying she was unable to accept the claimants' submission.

“The Defendant [Kensington & Chelsea] considered the BPP at length with the benefit of its knowledge and experience as a local planning authority which routinely deals with permitted development rights,” the High Court judge said.

“The Defendant was considering a change to the existing policy, set out in the 2009 SPD on basements, which described permitted development rights in that context. The Inspector's report was before the Council which expressly referred to permitted development rights in paragraph 38.”

The judge added that:

  • The defendant authority had analysed the permitted development rights in the consultation and draft policy stages, “expressly identifying the problem of a lack of planning control over noise and loss of amenity arising from basements constructed under permitted development rights”.
  • The council had indicated on several occasions that it was considering an Article 4 direction to remove permitted development rights to address this problem, but that would require a separate procedure. “In my view, its subsequent decision to do so was consistent with its previously stated intention, not a response to the claimants' legal challenge.”
  • Paragraph 34.3.72 of the BPP made provision for the ongoing monitoring of the policy to assess its effectiveness, and there was a specific monitoring requirement in respect of the number of basements built under permitted development rights, with a mechanism to trigger a review of the effectiveness of the policy, should there be a doubling in the number of basements constructed. “This provision both acknowledged and addressed the risk of an increase in basement construction under permitted development rights.”
  • The claimants had argued that the BPP should not have been adopted because of the risk of increased basement construction under permitted development rights; an approach which served their underlying objective of defeating the BPP altogether. “However, that is an exercise of judgment which ultimately is not theirs to make," the judge said. At times…. they seemed to be suggesting that, because the Defendant went ahead and adopted the BPP, it must have ignored the significance of permitted development rights. As I see it, the Defendant simply took a different approach to the benefits of the BPP, even taking account of the potential problem with permitted development rights.”

The second ground advanced by the second claimant (Force Foundations) was that Kensington & Chelsea and the planning inspector had failed to consider and/or assess the ‘reasonable alternative’ of a ‘case by case’ approach it put forward, and so the council had failed to carry out an adequate environmental assessment, as required under reg. 5 of the Environmental Assessment of Plans and Programmes Regulations 2004.

Mrs Justice Lang also rejected this argument. She followed the Court of Appeal ruling in Ashdown Forest Economic Development LLP v Wealden District Council and South Downs National Park Authority [2015 EWCA Civ 681, where Lord Justice Richards agreed that the identification of reasonable alternatives was “a matter of evaluative assessment for the local planning authority, subject to review by the court on normal public law principles, including Wednesbury unreasonableness”.

Mrs Justice Lang said: “In this case, the Defendant was well aware of its obligation to assess reasonable alternatives, and did so.”

The High Court judge added: “The second claimant has presented arguments why the Inspector and the Defendant ought not to have concluded that its option was not a reasonable alternative means of achieving the policy objectives, but these are merits-based challenges to the evaluative judgment which has been entrusted to the Defendant.

“They reflect the Second Claimant's profound disagreement with the Defendant's policy. Contrary to Mr Brown's submission, the court only has a supervisory role, applying conventional public law principles. In my judgment, the Defendant's decision, supported by the Inspector, was a reasonable one, reached after taking into account the relevant considerations. It was adequately explained and justified.”

Mrs Justice Lang concluded that, in her judgment, Kensington & Chelsea had “complied with its statutory obligations in its preparation of the SA [Sustainability Appraisal] and the SEA”.

Following the judgment, Cllr Timothy Coleridge, Cabinet Member for Planning Policy at Kensington & Chelsea, said: “We’re obviously pleased and relieved that the judge has rejected this appeal.

“Our policy brings some much-needed sanity to the mega-basement mania and finds the proper balance between subterranean development and the right of the rest of the community to the peaceful enjoyment of their homes.

“It’s a policy that has already been the subject of two years’ of consultation, debate and legal argument. And it is also a policy that is very popular and being copied by others. It deserves to stand.” 

Timothy Straker QC and Dilpreet Dhanoa of 4-5 Gray’s Inn Square appeared for the council.

Paul Brown QC of Landmark Chambers and Harriet Townsend of Cornerstone Barristers acted for the claimants.