Going underground – High Court shines a light on basement development rights

01 Jan 2018

Housing, Planning and Environment, Property

No specific provision is made for basements in the Town and Country Planning (General Permitted Development) Order 1995 (now the 2015 Order). However, the vast majority of local authorities have treated such development as benefitting from permitted development rights. The advantages of proceeding in this way are clear, not least for the developer, who will avoid the need for a planning application, to which a specific basements policy may well apply (and in Kensington and Chelsea, for example, the basements policy is far from uncontroversial – see below).

While many local authorities accept that Class A permitted development rights (for “the enlargement, improvement or other alteration of a dwellinghouse”) attach to basements, the scope of such permitted development rights has been unclear, particularly given the absence of any technical guidance.

In two conjoined challenges by the Royal Borough of Kensington and Chelsea to Inspectors’ appeal decisions to grant lawful development certificates (at 85 Princes Gate Mews and 6 Colbeck Mews), Mrs Justice Patterson, sitting in the Planning Court, has finally brought clarity to a number of issues arising under Class A of Part 1 of Schedule 2 to the 1995 Order.

The two developments in question consisted of the addition of a single storey basement to an existing dwelling, no part of which would go beyond the perimeter of the existing dwelling.

Pursuant to paragraph A.1(f)(ii) of the 1995 Order permitted development rights are expressly excluded where:

The enlarged part of the dwellinghouse would have more than one storey and … be within 7 metres of any boundary of the curtilage of the dwellinghouse opposite the rear wall of the dwellinghouse. [Class A.1(f)ii) with emphasis added].

The local planning authority and the Secretary of State agreed that permitted development rights in question apply to development both above and below ground.

However, the principal questions before the court were:

Whether the “enlarged part” of the dwellinghouse is simply the single storey basement (as the Secretary of State contended), or whether (as the Council contended) it includes the existing storeys within the dwellinghouse to which the development was added; and

Whether the 7 metre restriction is to be measured from any dwellinghouse opposite the the dwellinghouse being developed (as the Inspector had decided in the 85 Princes Gate Mews appeal, fastening on the phrase “the dwellinghouse opposite”) or whether the 7m restriction is to be measured from the dwellinghouse being developed (as the Council argued).

In the 6 Colbeck Mews appeal, the inspector had found that the restriction in A.1(f)(ii) did not apply, because the overall height of the dwellinghouse had not been increased.

The Secretary of State conceded the case in relation to the 7 metre restriction so that it was agreed (and the Judge found) that the 7m restriction throughout paragraph A.1f(ii) is measured from the subject dwellinghouse. The Secretary of State did not seek to defend the 6 Colbeck Mews decision on the basis that the overall height of the dwellinghouse had not increased.

However, the Secretary of State maintained that both the inspectors’ decisions were correct, not for the reasons given by his inspectors, but because “the enlarged part of the dwellinghouse” referred solely to the development being added by way of permitted development rights with the consequence that the development did not have “more than one storey”.

The judge agreed with the Secretary of State on this point and dismissed the Council’s appeals, upholding the inspectors’ decisions to grant the certificates, notwithstanding the errors in the decisions.

This judgment brings much needed clarity to the interpretation of the provisions of the GPDO (which are materially identical in the 2015 Order) not only in relation to basement development, but also in relation to above ground extensions.

In Kensington and Chelsea, however, the battle of the basement rumbles on. On 7 July 2015 the planning court will hear a legal challenge to the adoption by the Council of its basement policy [Core Strategy policy CL7] and on the 27 October the Court has listed the challenge made by the Council to an appeal decision granting planning permission at 34 Egerton Crescent as an exception to their recently adopted policy.

Mark Lowe QC and Jack Parker acted for the Royal Borough of Kensington and Chelsea.

Philip Coppel QC and Ryan Kohli acted for the Secretary of State.

In the challenge to the Council’s Basements Policy, Harriet Townsend is junior counsel for the Claimants.

In the challenge to the 34 Egerton Crescent appeal decision, Mark Lowe QC and Jack Parker are acting for the Royal Borough of Kensington and Chelsea. Ryan Kohli is instructed for the Secretary of State.

Click here to read the judgement in full. For more information call 020 7242 4986 or email clerks@cornerstonebarristers.com.