QUEEN'S BENCH DIVISION
THE ADMINISTRATIVE COURT
London WC2A 2LL
B e f o r e :
(Sitting as a Deputy Judge of the High Court)
|THE QUEEN ON THE APPLICATION OF HILTON||Claimant|
|SECRETARY OF STATE FOR THE HOME DEPARTMENT||Defendant|
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Mr Jack Parker (instructed by Government Legal Department) appeared on behalf of the Defendant
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" Development is not permitted by Class A if -
(f) subject to paragraph (g), 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 4 metres in the case of a detached dwellinghouse, or 3 metres in the case of any other dwellinghouse, or
(ii) exceed 4 metres in height."
Exception (g) provides, until 30 May 2019, for a similar extension substituting eight metres and six metres respectively for the extension beyond the rear wall for a detached or any other dwellinghouse.
The Claimant appealed. The appeal was dismissed by decision letter dated 17 December 2016. In paragraph 6 of the decision letter the Inspector identified as the main issues whether the proposed single-storey rear extension would be permitted development and, if so, the effect on the amenity of neighbouring occupiers. At paragraph 7 he continued:
"7 The proposed single-storey rear extension would project some 2.3 metres beyond the existing rear wall of this previously extended semi-detached house. As the proposed extension, together with the existing extension, would project some 5.1 metres to the rear of the rear main wall of the original dwelling, the overall enlargement of the house would not exceed six metres. On this basis, and because the maximum height of the new extension would be around 2.8 metres, the appellant submits that it would be permitted development.
8 There is, however, some disagreement between the parties concerning the enlarged part of the dwellinghouse. There is no dispute that the existing extension includes both two-storey and single-storey elements. As such, the council maintains that even though the additional extension now proposed would have only a single storey the enlarged part of the house would include more than a single storey, whereas the appellant contends that the enlarged part would have a single storey."
He continued at paragraph 12:
"12 Moreover, the question of whether existing extensions are part of the enlargement of a building was examined in Kensington & Chelsea Royal Borough Council v SSCLG  EWHC 2458 (Admin). It was held that the 'enlarged part of the dwellinghouse' does not include the 'original' building, but does include previous enlargements.
13 In this appeal, the proposed extension would, taken together with the existing extension, not be a single-storey enlargement to the dwellinghouse. It would not, therefore, be permitted development under the terms of Part 1 Class A.1(g)(i) of the GPDO. Furthermore, as the enlarged part of the house would exceed 4 metres in height on account of part of the existing extension having two storeys, the proposal would not be permitted development under the terms of Part 1 Class A.1 (g)(ii) of the GPDO.
14 Since the proposal would not be permitted development, it is not necessary to consider the effect on the amenity of the neighbouring occupiers in this case."
" ..... does not include a building containing one or more flats ..... "
"Flat" is defined as meaning -
" ..... a separate and self-contained set of premises constructed or adapted for use for the purpose of a dwelling and forming part of a building from some other part of which it is divided horizontally."
"Existing" is defined as
"in relation to any building ..... (except in the definition of 'original') existing immediately before the carrying out, in relation to that building ..... of development described in this Order."
"original" is defined as -
"(a) in relation to a building, other than a building which is Crown land, existing on 1st July 1948, as existing on that date;
(b) in relation to a building, other than a building which is Crown land, built on or after 1st July 1948, as so built;
"(k) it would consist of or include -
(i) the construction or provision of a verandah, balcony or raised platform,
(ii) the installation, alteration or replacement of a microwave antenna,
(iii) the installation, alteration or replacement of a chimney, flue or soil and vent pipe, or
(iv) an alteration to any part of the roof of the dwellinghouse."
Those exceptions are made because they are specifically addressed under other classes within Part 1.
Other specific exceptions are provided under the preceding subparagraphs in paragraph A.1. In my view it is relevant to look at a number of these on the basis that one can reasonably assume that generally the draftsman would use similar terms in the same statutory instrument with a similar meaning.
"(b) as a result of the works, the total area of ground covered by buildings within the curtilage of the dwellinghouse (other than the original dwellinghouse) would exceed 50% of the total area of the curtilage (excluding the ground area of the original dwellinghouse)."
"(c) the height of the part of the dwellinghouse enlarged, improved or altered would exceed the height of the highest part of the roof of the existing dwellinghouse."
"(i) forms the principal elevation of the original dwellinghouse; or
(ii) fronts a highway and forms the side elevation of the original dwellinghouse."
"(5) The local planning authority must notify each adjoining owner or occupier about the proposed development by serving on them a notice which -
(a) describes the proposed development, including -
(ii) the maximum height of the enlarged part of the dwellinghouse; and
(iii) the height of the eaves of the enlarged part of the dwellinghouse."
"(h) the enlarged part of the dwellinghouse would have more than a single storey and -
(i) extend beyond the rear wall of the original dwellinghouse by more than 3 metres, or
(ii) be within 7 metres of any boundary of the curtilage of the dwellinghouse being enlarged opposite the rear wall of the dwellinghouse."
"(i) the enlarged part of the dwellinghouse would be within 2 metres of the boundary of the curtilage of the dwellinghouse, and the height of the eaves of the enlarged part would exceed 3 metres."
This is, again, complementary to the earlier exceptions. The distance is reduced to within two metres and applies to the part of the dwellinghouse that would be enlarged under Class A where the eaves of the part being enlarged pursuant to the permitted development would exceed three metres. This seems to me consistent with principle as an approach. I see no material risk of piggy-backing or other difficulty. On the contrary, it seems to me a straightforward and logical approach.
"(j) the enlarged part of the dwellinghouse would extend beyond a wall forming a side elevation of the original dwellinghouse, and would -
(i) exceed 4 metres in height,
(ii) have more than a single storey, or
(iii) have a width greater than half the width of the original dwellinghouse."
That test would be straightforward to apply in comparing the proposed Class A enlargement of the dwellinghouse with the side wall of the original dwellinghouse, as defined, to see whether it extends beyond it. If it does, then the exception will apply, if the Class A enlargement would exceed four metres in height or be more than one storey or if it would have a width greater than half the width of the original dwellinghouse. There is nothing absurd about applying the tests on that basis which can be applied objectively and consistently with the remainder of the Class A exceptions.
"The enlargement of a dwellinghouse consisting of an addition or alteration to its roof."
Paragraph B.1 provides exceptions to that permitted development:
"Development is not permitted by Class B if -
(b) any part of the dwellinghouse would, as a result of the works, exceed the height of the highest part of the existing roof."
As defined, the existing roof is that existing before the Class B enlargement is carried out. Thus the exception is to be applied by considering the part of the dwellinghouse, which is the subject of the proposed Class B enlargement and comparing that to the highest part of the dwellinghouse as it existed immediately before the proposed development, whether extended under the permitted development or otherwise.
"(c) any part of the dwellinghouse would, as a result of the works, extend beyond the plane of any existing roof slope which forms the principal elevation of the dwellinghouse and fronts a highway."
Again, the same approach is to be taken comparing the proposed works under Class B with any roof slope of the dwellinghouse as existed immediately before those works, whether the original dwellinghouse or as extended or altered.
"(d) the cubic content of the resulting roof space would exceed the cubic content of the original roof space by more than -
(i) 40 cubic metres in the case of a terrace house, or
(ii) 50 cubic metres in any other case."
This exception again focuses on the enlargement of the roof forming part of Class B.
I should also note that in this respect Mr Wills drew attention to the definition of the resulting roof space in paragraph B.3 as:
" ..... the roof space as enlarged, taking into account any enlargement to the original roof space, whether permitted by this Class or not."
Mr Wills submitted that, in so far as it was thought necessary to specify that earlier enlargement is to be taken into account in this case , in the exceptions relevant to the present claim, where that has not been specified, it should be assumed that it was not intended that earlier extensions should be taken into account. However, while the submission is consistent with the approach which I have adopted, I am not persuaded that in itself it is of particular weight as an argument.
" ..... whether the phrase 'the enlarged part of the dwelling house would have more than one storey' in paragraph A.1 (f) is referring to the dwelling house as enlarged by development, i.e. to include the original dwelling house, or whether it is referring to that part of the dwelling house permission for which is given by Class A of the GPDO."
" Within paragraph A.1 (f) the draftsman has drawn a distinction between 'the enlarged part of the dwelling house' and the 'original dwelling house'. That has clearly been done with a purpose and, in my judgment, is to clarify the interpretation of the paragraph.
 They refer to two different things. The 'enlarged part' is referring to the development permitted under the GPDO. The 'original dwelling house' is the dwelling house as defined in accordance with Article 1 of the GPDO. 'Original' is defined in Article 1 of the GPDO:
''Original' means, in relation to a building existing on 1 July 1948, as existing on that date and, in relation to a building built on or after 1 July 1948, as so built.'
 The Claimant's submission that 'enlarged part' incorporates the original is artificial and, in my judgment, offends the natural language used in Class A.1(f).
 Further, when Class A is read as a whole it is clear that 'it' refers either to the subject immediately preceding, i.e. the enlarged part of the dwelling house, or back to the opening words 'development is not permitted by Class A.1 (f)'.
 The purpose of the GPDO is to compare what is proposed with what existed prior to the proposal to ascertain whether the exceptions are engaged. That is why it is important to have a definition of the 'original' under Article 1.
 The Claimant contends that such an approach will not catch 'piggybacking' or incremental development. I reject that submission. Article A.1(f) is dealing with the enlargement or alterations to the original dwelling house. Each step of incremental development has, therefore, to be judged against that baseline so that incremental development is caught each time it is proposed.
 I accept the submissions of the Defendant that 'part' cannot be characterised as meaning the whole of the dwelling house as enlarged. The original dwelling house and the enlarged part of the house may combine to make a dwelling house as enlarged, but they are two separate components. That interpretation has the advantage of being both straightforward and consistent with the language used."
The judge concluded in paragraph 43:
" It follows that the 'enlarged part of the dwelling house' is referring solely to that which is the subject of permission granted under the development order. The first issue, therefore, I determine in favour of the Defendants."