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Appeal Decision 128 - Certificate of Lawful Development.

This appeal decision summary and assessment has been produced by Planning Jungle Limited.  For more information, please go to


July 2010 - Code a00128


Summary of Case (appeal allowed): 


The property is a detached house, with its south elevation fronting the road. It has a rectangular shape, with narrower south and north elevations, and wider west and east elevations. The application was for a proposed single storey extension, which would have covered the whole of the north elevation, and would have projected eastward to a point approx 12m beyond the line of the east elevation. It would have a dual-pitched roof with eaves at 2.9m and ridge-line at 3.9m. 


The Council argued that the south elevation of this property is the “principal elevation”. By this interpretation, the proposed extension would extend beyond the north (rear) elevation by more than 4m, and would extend beyond the east (side) elevation with a width (as measured from west to east) that would be more than half the width of the house (as measured from west to east). 


The appellant argued that the east elevation of this property is the “principal elevation”. By this interpretation, the proposed extension would extend beyond the north (side) elevation with a width (as measured from north to south) that would be less than half the width of the house (as measured from north to south), and the amount by which it would extend beyond the east (principal) elevation would not be directly restricted by any limitation (because the principal elevation does not front a highway). 


The Inspector stated the following: 


“The appeal property sits on the corner of, and is accessed from, [the road] and when viewed from this approach appears as a modest house with a somewhat unbalanced, featureless, facade with non-central porch and single windows. When entering into the garden to the east the elevation with which one is faced is a stark contrast. Large bay windows sit under individual protruding gable ends with entrance towards the centre of the facade. The west and north elevations are also plain facades with smaller windows. To the north and west are three detached properties sitting on similar plot sizes. I have no reason to disagree with the appellant’s view that these houses formed part of an original ‘cluster’. 


The appellant argues that the east facing elevation is the principal elevation as it has all the architectural detail and the main living rooms facing out from it. He refers to the document Changes To Householder Permitted Development 1 October 2008 - Informal Views From Communities And Local Government which states; “in the vast majority of cases it would be perfectly clear what the principal elevation was i.e. the part of the house that fronts the highway and which usually contains the main entrance”. It goes on to say; “in a minority of cases there will have to be an assessment by the planning authority on a case by case basis as to what constitutes the principal elevation”.  


I have no doubt that this is one such case and I do not accept the Council’s view. The porch on the south facing elevation does give the impression, from the road, that it could be serving the principal elevation. However, the double bay windows, serving the east elevation and positioned asymmetrically, are typical of what would normally be expected to be found on a front elevation with entrance to the centre. When viewed as a whole and set against the immediate neighbours to the north and west, to my mind, any person viewing the property would conclude that the entrance was to ‘the side or flank’ of the house and the eastern elevation was the principal elevation of the house. 


For these reasons I find that, in the particular circumstances of this case, the eastern elevation should be regarded as the principal elevation. Therefore, the conservatory would not extend beyond the rear (west facing) wall of the original dwellinghouse by more than 4 metres, or exceed 4 metres in height, and would not fall foul of Class A, A.1(e) of the GPDO. 


I now turn to criterion (h)(iii) of section A.1 of the GPDO. The Council have interpreted the width of the proposed development to be 20 metres. I do not accept that view. Had I found the principal elevation was to the south then the width of the main house would be between the east and west sides. That would then apply to the proposed extension. However, given the principal elevation is, in my opinion, that facing east then it follows that the south and north elevations are the sides from which the measurement of width should be taken. 


When that argument is applied to the proposed extension it is evident that whilst the proposed extension would extend beyond a wall forming a side elevation of the original dwellinghouse it would not be greater than half the width of the original dwellinghouse. The appellant’s figures and drawings are undisputed and show the measurement of the existing dwelling (north to south) at approximately 18 metres and the proposal (north to south) at approximately 6 metres and thereby less than half the width. Therefore the proposal would also meet criterion (h)(iii) of the GPDO.” 


[Note: The Inspector appears to have taken the existing two-storey flat-roof extension on the north elevation to be “original”. As such, in his assessment of Class A, part A.1(h)(iii), he has included the width of this existing extension in his measurement of the width of the “original dwellinghouse” and excluded it from his calculation of the width of “the enlarged part of the dwellinghouse”. For this to be correct, this existing two-storey flat-roof extension would have had to have been constructed prior to 1948]. 


[Note: Subsequent to the above appeal decision, the DCLG - Informal Views from Communities and Local Government (Dec 2008, updated Jan 2009, superseded Aug 2010) was replaced by the “DCLG - Permitted development for householders - Technical guidance” (August 2010)]. 


Main Conclusions: 


·       This appeal decision provides an example of the types of factors that should be taken into consideration when determining which elevation is “the principal elevation”.
[Relevant to: “Principal Elevation”, A.1(d), B.1(b), E.1(b), F.1, G.1(b)].

·       The “principal elevation” is not necessarily the elevation that fronts a highway.
[Relevant to: “Principal Elevation”, A.1(d), B.1(b), E.1(b), F.1, G.1(b)].


·       The principal elevation is not necessarily the elevation that contains the main entrance.
[Relevant to: “Principal Elevation”, A.1(d), B.1(b), E.1(b), F.1, G.1(b)].


·       Where the principal elevation does not front a highway, an extension can extend in front of the principal elevation.
[Relevant to: “Principal Elevation”, A.1(d)].


·       Furthermore, in such cases, the amount by which the extension can extend beyond the principal elevation does not appear to be directly* restricted by any limitation.
(*i.e. other than the general requirement to remain within the “curtilage”, and the general restriction of A.1(a) that prevents more than 50% of the original garden being covered by buildings).
[Relevant to: “Principal Elevation”, A.1(d)].


·       For the purposes of Class A, part A.1(h), “width” should be measured in the direction parallel with the line of the principal elevation. For example, if the principal elevation is (say) the south elevation, then width should be measured from west to east, and not from north to south.
[Relevant to: A.1(h)].


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


·       Appeal Decision Notice: 

·       Existing and Proposed East Elevations: 

·       Existing and Proposed North Elevations: 

·       Proposed Site Plan: 

·       Proposed Roof Plan: 

·       Agent’s Planning Statement: 





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