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Appeal Decision 177 - Certificate of Lawful Development.

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December 2010 - Code a00177


Summary of Case (appeal allowed): 


The property is a two-storey detached house. The application was for a very long outbuilding that would be detached from the rear wall of the original house by just 2.5cm. 


The key issue was whether a structure in such close proximity to the main house would fall under Class A, which relates to “The enlargement, improvement or other alteration of a dwellinghouse”, or under Class E, which relates to “The provision within the curtilage of the dwellinghouse of … any building …”. 


The Inspector stated the following: 


“The application drawings show a single storey flat roofed building with a maximum height of 2.5 m. It would be sited very close to the rear wall of the existing dwelling, but the submitted drawing is annotated "wall will not be attached to rear elevation". The plan does not appear to show the wall of the proposed development being attached to the existing dwelling, and the appeal statement says that the position of the building is set away from the rear elevation by approximately 25 mm. 


The description of the proposed development in the heading is as set out in the application form. The Council in its decision notice describes the proposed development as "erection of single storey side/rear extension". If the building were to be properly regarded as an "extension" falling under Class A of Schedule 2 Part 1 of the GPDO1 ("the enlargement, improvement or other alteration of a dwelling house") rather than a curtilage building falling under Class E, then it would not be permitted development because its rearward projection would exceed the limitations in Class A.1. The appellant, however, argues that it should properly be regarded as a curtilage building under Class E, in which case the proposed development would not infringe any of the limitations in Class E.1. 


The relevant part of Class E permits the provision within the curtilage of the dwelling house of "any building or enclosure... required for a purpose incidental to the enjoyment of the dwelling house as such...". Class E.1(h) excludes from permitted development rights under Class E any development which "relates to a dwelling", for example extensions to a house which are covered by other classes of the rules on permitted development. 


Before October 2008, any curtilage building of more than 10 cubic metres constructed within 5 metres of an existing dwelling would have been treated as an enlargement of the dwellinghouse and so considered under Class A. That limitation was explicitly removed from the GPDO amendments which came into force in October 2008.  


The submitted drawing of the proposed building clearly and unambiguously shows that no part of the new building would contact the existing building and it would be completely detached from the main dwelling. The Council argues that the proposal requires steps down within the kitchen of the dwelling to provide access to the new structure, and that this demonstrates the integral and functional link between the proposed structure and the dwelling. However, although the drawings show alterations to the existing ground floor of the dwelling to provide these steps, and a new door which would lead directly into a door into the proposed structure, those alterations are not essential for the proposed structure because it would have its own separate entrance leading onto, together with windows looking out over, the rear garden. 


There is no justification for the Council's argument that a key characteristic of an outbuilding is the need for someone moving from the dwelling to an outbuilding to go outside and be exposed to the elements. In my view, the key characteristic of a curtilage building under Class E is that it should not be attached to the main dwelling. This building would not be attached to the dwelling, and the fact that a door from the dwelling would lead directly into a door into the building does not turn a detached building into an enlargement of the dwelling. The Council also argues that eaves could be constructed eliminating the 25 mm gap. But even if that happened (and the proposal before me does not show any such eaves) the result would be that the two buildings might be touching, but would not be attached to each other. 


It is also argued that the proposal would be contrary to the intentions of the amended GPDO. However, that is belied by the explicit removal in October 2008 of the limitation relating to curtilage buildings of more than 10 cubic metres. Had it been intended that some curtilage buildings should not be permitted because of their proximity to the dwelling, then it would be reasonable to expect that to be stated explicitly in the GPDO amendments. To adopt the approach argued by the Council would be to leave open the question, exactly how far from the dwelling the curtilage building should be in order to be permitted development, and would remove a significant element of certainty and clarity from Class E. 


Under these circumstances, I consider that despite its proximity to the dwellinghouse the building would be a separate structure within the curtilage and not an enlargement of the dwelling. It therefore falls to be considered under Class E because it involves “the provision within the curtilage of the dwellinghouse of... any building...”.” 


[Note: For my comments on the above appeal decision, please refer to my comments for June 2010 - Code a00121 (this previous appeal decision included the same conclusion that a detached structure separated from the main house by only a token amount would still fall under Class E). 


It should be noted that both of these appeal decisions were by the same Inspector. In my opinion, the weight that should be given to a particular interpretation increases not only if it is supported by more individual appeal decisions, but also if it is supported by more individual Inspectors. 


As an illustration of how one or two appeal decisions are not necessarily conclusive, in March 2010 I undertook a (quick) analysis of all of the appeal decisions in this document until that date (106 different appeal decisions), and calculated that at least 15% of appeal decisions contain at least one incorrect legal interpretation. I calculated this figure with the most cautious method possible by looking at each group of cases where conflicting interpretations had been applied by different appeal decisions, and by then assuming that the interpretation supported by the majority of appeal decisions was correct (which minimised the number of appeal decisions that were considered to be incorrect). 


In my opinion, taking all of the above into consideration, LPAs would be entitled to continue to form their own interpretations of this particular issue until further guidance or appeal decisions become available]. 


Main Conclusions: 


·       Even if a detached structure would be separated from the main house by only a very small (i.e. token) amount, this would still be sufficient for the structure to fall under Class E (“the provision within the curtilage of the dwellinghouse of … any building …”) rather than Class A (“the enlargement, improvement or other alteration of a dwellinghouse”).
[Relevant to: “Interaction between Class A and Class E”, Class A, Class E].


Links to the “Appeal Decision Notice” and other associated documents (e.g. drawings, etc): 


·       Appeal Decision Notice: 

·       OS Map: 

·       Drawing 1: 

·       Drawing 2: 




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