The London Borough of Newham have succeeded in the High Court in a section 289 appeal challenging the Secretary of State’s decision on the construction of Class A.1(g) in the General Permitted Development Order 2015 relating to rear extensions to dwellings.

In combination with article 3(1) of the GPDO, Class A of Part 1 grants planning permission for various proposals for “the enlargement, improvement or other alteration of a dwellinghouse”, see para. A.1.  Such permitted operations include rear extensions to dwellings.

Under para. A.2 of Class A of Schedule 2 to the GPDO, construction of a rear extension under Class A.1(g) is not permitted if:

“…the enlarged part of the dwellinghouse would have a single storey and –

(i) extend beyond the rear wall of the original dwellinghouse by more than 8 metres in the case of a detached dwellinghouse, or 6 metres in the case of any other dwellinghouse, or

(ii) exceed 4 metres in height.”

Class A1(g) allows extensions of larger dimensions than those covered by the general permission under Class A.1(f) and is subject to significant additional requirements including consultation of neighbours in certain specified circumstances as referred to below.  It is a more generous permission than that under Class A.1(f) but is limited in time by a cut-off date of 30 May 2019.

The Secretary of State’s Inspector decided the question of the dimensions of the extension as built in the developer’s favour in paras. 8 to 10 of his decision letter as follows:

8. The appellant argues that the rear extension is development permitted under the provisions of Class A of Part 1 to Schedule 2 of the GPDO. Class A permits the enlargement, improvement or other alteration of a dwellinghouse. Various preclusions are set out in paragraph A.1…

9. The Council say that the overall length of the rear extension is 6.3 metres, plus an additional 1.7 metres for the boiler cupboard attached to its end – a total of 8 metres. However, the appellant says that there was originally a single-storey extension beyond the two-storey outshot, which matched a similar single storey extension on no. 12, the adjoining house to the east. This was largely demolished, or partly incorporated into the new extension then built. Looking at the back of no. 12 it appears to me on the balance of probabilities this was likely to have been the case, and that this would have been the rear wall of the original dwellinghouse.

10. The original single-storey extension was itself about 3 metres deep, and the back wall of new extension is 3 metres beyond that, with the boiler cupboard adding a further 1.7 metres. The total depth beyond the original back wall is therefore 4.7 metres, and the height is significantly less than 4 metres. The new extension therefore comes within the limits set by paragraph A.1(g). It follows that the single-storey rear extension is development permitted under Class A of Part 1 to Schedule 2 of the GPDO…”

However, in so concluding, the Inspector failed to address the fact that extensions which come within the permitted development right conferred by Class A.1(g) are subject to express “conditions” requiring procedural safeguards to be observed before development can be begun including a requirement for advance notification to the Council concerned and prior approval by them of the impact of the proposed extension on the “amenity of any adjoining premises” where “any owner or occupier of any adjoining premises” has objected, see para. A.4(1).

As no advance notification of the construction of the extension was given to the Council as required, the procedural safeguards in para. A.4(1) were not observed, no opportunity was given to adjoining owners or occupiers to object and there was no consideration by the Council of the need for prior approval of the proposal.

The Council therefore appealed to the High Court under section 289 of the 1990 Act and submitted that the Inspector had erred in law in deciding that the matters alleged in their enforcement notice relating to the extension did not constitute a “breach of planning control”.  The Council submitted that since a “breach of planning control” includes “failing to comply with any condition or limitation subject to which planning permission is granted” under section 171A(1)(b) of the 1990 Act, the requirements of the “conditions” in para. A.4.1 meant that it could not be said that the extension was within the terms of the permission granted under Class A.1(g).

The Council further submitted that the developer’s decision not to pursue a planning merits appeal under section 174(2)(a) meant that it could not be said that the Inspector’s decision would have been the same in any event if he had gone on to consider the impact on neighbours and found that acceptable.

On receipt of the appeal, the Secretary of State indicated that he would not seek to defend it and the developer submitted to judgment after the grant of permission to appeal by the court and the enforcement notice appeal will be remitted for redetermination.

Meyric Lewis was instructed on the High Court appeal by Michael Woods and James Liebetrau of the London Borough of Newham.