IMPORTANT: High Court judgment about the phrase “the enlarged part of the dwellinghouse” within Part 1 Class A of the GPDO …

Introduction:

The "Landmark Chambers" website (link) states that the following High Court judgment has found that the phrase "the enlarged part of the dwellinghouse" within Part 1 Class A of the GPDO included only that which was being proposed under Part 1 Class A:

  • Hilton, R (on the application of) v Secretary of State for the Home Department [2016] EWHC 1861 (Admin) (15 June 2016).
    [UPDATE: The transcript for the above High Court judgment is now available as a free-to-view transcript on the Bailii.org website (link)].

As such, the above High Court judgment appears to support the interpretation that where a proposed extension would be attached to an existing extension, then the phrase "the enlarged part of the dwellinghouse" applies to only the proposed extension. In other words, only the proposed extension should be assessed against those limitations and conditions of Part 1 Class A that apply to "the enlarged part of the dwellinghouse". This is a relatively significant interpretation that contradicts the DCLG "Technical Guidance" document and contradicts the majority of appeal decisions that have dealt with this particular issue (for more info, please see below).

Further information:

The above High Court judgment relates to an application for prior approval (i.e. for a "larger home extension") that was submitted under Part 1 Class A of the GPDO 2015. The property is a two-storey semi-detached house, with an existing rear extension that was granted planning permission by the Council in 2000. This existing rear extension covers the full-width of the house, is two-storey for most of its width and single-storey for the remaining part of its width, and has length approx 2.8m. The application for prior approval was for a proposed single storey rear extension that would be added onto the end of the existing rear extension. The proposed rear extension (in itself) would cover the full-width of the house, would be single storey, and would have length approx 2.3m. As such, the combined structure would cover the full-width of the house, would be a mixture of two-storey and single storey, and would have length approx 5.1m.

The Council refused prior approval, and the applicant submitted an appeal to the Planning Inspectorate (reference "APP/D5120/D/15/3129892"). The Inspector dismissed the appeal, and in the appeal decision notice the Inspector stated the following;

"12. Moreover, the question of whether existing extensions are part of the enlargement of a building was examined in Kensington and Chelsea RBC v SSCLG [2015] 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 4m 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."

Note: As shown above, the Inspector refers to the (previous) High Court judgment "Royal Borough of Kensington and Chelsea v Secretary of State for Communities and Local Government [2015] EWHC 2458 (Admin) (17 June 2015)". For more info, please view paragraphs 32 to 46 of the free-to-view transcript (link) on the Bailii.org website. In my opinion, these paragraphs support the interpretation that the phrase "the enlarged part of the dwellinghouse" does not include "the original dwellinghouse". However, in my opinion, it's not clear how to apply these paragraphs to the situation where the house has an existing extension. For example, in paragraph 38 the judge states that "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", and in paragraph 45 the judge states that "If a decision maker were to be dealing with a series of sequential and incremental developments, therefore, each one would be caught". In my opinion, these statements might be the reason why the Inspector for the above appeal concludes that "It was held [by this High Court judgment] that the ‘enlarged part of the dwellinghouse’ does not include the ‘original’ building, but does include previous enlargements" [my emphasis].

The "Landmark Chambers" website (link) summaries the new High Court judgment (i.e. "Hilton v Secretary of State for Communities and Local Government (2016)") as follows:

"The court held that the Inspector was wrong, and that the "enlarged part" of a dwellinghouse for the purposes of Class A included only that which was being proposed under Class A."

In other words, it appears that for the application for prior approval subject of the above High Court judgment, the judge found that the phrase "the enlarged part of the dwellinghouse" applies to only the proposed extension (i.e. the new single storey rear extension), and not to the combined structure (i.e. the resulting part two-storey / part single storey rear extension).

Notes about the DCLG "Technical Guidance" document:

It's important to note that the above High Court judgment contradicts the DCLG "Technical Guidance" document. This is because the latter document supports the interpretation that where a proposed extension would be attached to an existing extension, then the phrase "the enlarged part of the dwellinghouse" applies to the combined structure.

Since the DCLG "Technical Guidance" document was introduced in August 2010, it has indirectly supported the above interpretation. For example, the information on pages 27 and 28 of the "April 2016" version (link) of this document indicates that if a proposed rear extension would be attached to an existing side extension, then this would not be PD (i.e. on the basis that the combined structure would not be PD).

In addition, since the DCLG "Technical Guidance" document was amended in April 2016, it has directly supported the above interpretation. In particular, as noted by this previous post, page 7 of the "April 2016" version (link) of this document now sets out the following definition of the phrase "enlarged part of the house" [sic]:

""Enlarged part of the house" - is the part(s) of a dwellinghouse comprising any enlargements of the original house, whether built under permitted development rights or following any application for planning permission, and whether the enlargement is undertaken on a single occasion or added incrementally."

In my opinion, the government should now either amend the DCLG "Technical Guidance" document (i.e. to accord with the above High Court judgment) or amend the GPDO 2015 (i.e. to supersede the above High Court judgment). It should be noted that the "Secretary of State for Communities and Local Government" was the defendant for the above High Court judgment, which means that DCLG should already be fully aware of this judgment.

Notes about appeal decisions:

It's important to note that the above High Court judgment contradicts the majority of appeal decisions that have dealt with this particular issue. For reference, "The enlarged part of the dwellinghouse" topic of the "Part 1 of the GPDO - GENERAL Appeal Decisions" document currently contains the following appeal decisions that deal with the situation where a proposed extension would be attached to an existing extension:

  • 23 appeal decisions that state, or imply, that the phrase "the enlarged part of the dwellinghouse" applies to the combined structure.
  • 8 appeal decisions that state, or imply, that the phrase "the enlarged part of the dwellinghouse" applies to only the proposed extension.

The effects of the above High Court judgment:

One of the main effects of the above High Court judgment is that there will now be situations in which an extension that's not PD can be split into two extensions (i.e. undertaken as separate operations) that would be PD.

For example, as shown by the second illustration on page 26 of the "April 2016" version (link) of the DCLG "Technical Guidance" document, for a typical house (i.e. with a rectangular footprint), a side and rear extension is not PD. Furthermore, the illustration on page 27 indicates that this interpretation still applies even if such an extension is split into two extensions (i.e. a side extension and a rear extension undertaken as separate operations).

However, the above High Court judgment appears to support the interpretation that the above two extensions (i.e. a side extension and a rear extension undertaken as separate operations) would be PD. This is because the above High Court judgment indicates that when the proposed (rear) extension is added onto the existing (side) extension, then only the proposed extension should be assessed against those limitations and conditions of Part 1 Class A that apply to "the enlarged part of the dwellinghouse".

As such, in my opinion, the above High Court judgment increases the number of situations in which it's not PD for a house to go from "Layout 1" to "Layout 2" directly, but in which it would be PD for the house to go from "Layout 1" to "Layout 2" via "Layout 3".

Another of the main effects of the above High Court judgment relates to situations where a house has an existing extension that's lawful, but which already exceeds the tolerances of Part 1 Class A (e.g. the extension was granted PP by the Council, or was erected under a previous version of Part 1 Class A, or has become lawful via the passage of time, etc). There will now be situations in which it would be PD for a proposed extension to be added onto this existing extension.

For example, in the application for prior approval subject of the above High Court judgment, the house has an existing rear extension that's lawful (i.e. it was granted planning permission by the Council), but which already exceeds the tolerances of Part 1 Class A (i.e. it wouldn't accord with limitation A.1(i)). In my opinion, the DCLG "Technical Guidance" document indicates that it's not possible (under PD rights) for a proposed extension to be added onto this existing extension (i.e. on the basis that the combined structure should be assessed against those limitations and conditions of Part 1 Class A that apply to "the enlarged part of the dwellinghouse"). However, the above High Court judgment indicates that this would be possible (i.e. on the basis that only the proposed extension should be assessed against those limitations and conditions of Part 1 Class A that apply to "the enlarged part of the dwellinghouse").

Finally, it should be noted that the above High Court judgment also raises the question of how the phrase "the enlarged part of the dwellinghouse" relates to the phrases "a single storey" and "more than a single storey" within Part 1 Class A.

For example, suppose that a house on article 2(3) land (e.g. a conservation area) has an existing single storey rear extension, and suppose that the owner would like to erect a proposed first floor rear extension on top of this existing extension. In my opinion, the DCLG "Technical Guidance" document indicates that the phrase "the enlarged part of the dwellinghouse" applies to the combined structure (i.e. the resulting two-storey rear extension). In my opinion, it's clear that this combined structure would have "more than a single storey", and therefore it's clear that such development would be contrary to limitation A.2(c).

However, the above High Court judgment indicates that the phrase "the enlarged part of the dwellinghouse" applies to only the proposed extension (i.e. only the proposed first floor rear extension). In my opinion, this raises the question of whether this proposed first floor rear extension (in itself) would have "a single storey" or "more than a single storey". If the answer is "a single storey", then the development would not be contrary to limitation A.2(c) (even though this limitation is intended to prevent such development), albeit that the development would be contrary to limitation A.1(f)(ii) (even though this limitation is not intended to prevent such development).

In my opinion the above (new) question is similar to the (old) question of whether a proposed first floor extension on top of an original single storey projection would have "a single storey" or "more than a single storey". For reference, the ""More than one storey" / "More than a single storey"" topic of the "Part 1 of the GPDO - GENERAL Appeal Decisions" document currently contains 4 appeal decisions that have dealt with the latter question, although 2 of these appeal decisions support one interpretation, whereas the other 2 appeal decisions support the opposite interpretation.

Other notes:

  • The above High Court judgment is also summarised on the "Planning Resource" website (link).
  • The Planning Jungle website does not normally summarise court judgments. This is because a number of other websites already provide such a service, whereas the Planning Jungle website primarily summarises appeal decisions (particularly "LDC Appeals" relating to Part 1 of the GPDO). For such appeal decisions, where an Inspector refers to a court judgment within their decision notice, then this will normally be shown within the summary on the Planning Jungle website (because each summary normally includes quotes from the decision notice).
  • In accordance with the "Important Disclaimer" within the "Planning Jungle Limited - Membership Terms and Conditions", please note that the information within this post (like all of the information provided by Planning Jungle Limited) does not constitute legal or other professional advice, and must not be relied on as such.