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Appeal Decision 209 - Certificate of Lawful Development.

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February 2011 - Code a00209


Summary of Case (appeal dismissed): 


The property is a two-storey detached house with a hipped main roof. The property has an existing two-storey rear extension with a flat roof that meets the main rear roof at a level just above where the original rear eaves would have been (the latter have therefore been removed). The application was for a proposed rear dormer, the base of which would meet the flat roof of the existing two-storey rear extension. 


The key issue was whether the proposals would be contrary to Class B, part B.2(b), which states that “other than in the case of a hip-to-gable enlargement, the edge of the enlargement closest to the eaves of the original roof shall, so far as practicable, be not less than 20 centimetres from the eaves of the original roof”. 


The Inspector stated the following:


“In respect of condition B.2(b), by means of illustration, the aforementioned publication advises that the prescribed 20 cm dimension is the width of the margin of a retained portion of an original roof slope measured up the roof slope from the lowest edge of the tiles, slates or other roof covering at the eaves to the face of the structure which constitutes or would constitute the enlarged part of the house. In the case of this appeal proposal there would be no retained margin as the original eaves at the rear of the dwellinghouse have already been removed to accommodate the junction of a 2-storey flat roofed rear extension. Such removal is confirmed by the annotation “line of original eaves” on the revised plan. The outer wall of the proposed dormer would rise from the point where the flat roof intersects the pitched roof. However, insofar as the said condition is drafted to refer to the eaves of the original roof, the removal of the original eaves does negate the requirement to conform to the condition.” 


The Inspector then noted a number of inconsistencies with the submitted drawings, and then stated the following: 


“In the light of the doubt arising from the inconsistencies and inaccuracies of the application plans, including the revised plan, I do not consider it has been demonstrated that the 20 cm roof margin (notional in the case of this appeal proposal owing to the alterations already carried out to the roof of the original building) can be achieved between the former position of the outer edge of the original roof covering of the house at the appeal site and the outer face of the principal wall of the proposed dormer. However, I go so far as to say that, following a measured survey, it might be possible to prove conformity with the said condition by the preparation of accurate large scale details (not less than 1:5), showing, if necessary, the nominal repositioning of the proposed dormer. Such details could form the basis of a new application.” 


[Note: I am unsure whether I have understood the conclusions of this appeal decision correctly. In my opinion, the Inspector appears to be saying that if the applicant can demonstrate that the dormer would be set-back from the notional point of the original eaves by at least 20cm, then even though these original eaves have been removed, this would be sufficient to comply with Class B, part B.2(b). Assuming that this is indeed the conclusion of this appeal decision, then this would contradict the previous appeal decisions November 2009 - Code a00042 and March 2010 - Code a00105]. 


Main Conclusions: 


·       It is possible to comply with Class B, part B.2(b) by saying that the dormer would be set-back 20cm from the notional point where the original eaves would have been when the latter has been removed.
[Note: This would appear to contradict at least one other appeal decision – for further information see the entry in the “Reference Section” on “B.2(b)”].
[Relevant to: B.2(b)].


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


·       Appeal Decision Notice: 

·       OS Map: 

·       Existing Drawings: 

·       Proposed Drawings: 

·       Aerial Photo: 




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