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Appeal Decision 93 - Certificate of Lawful Development.

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February 2010 - Code a00093


Summary of Case (appeal dismissed): 


The property is a semi-detached house, with a hipped roof. The application was for a proposed hip-to-gable roof extension and a full-width rear dormer. 


The key issue was whether the proposed dormer would be contrary to Class B, part B.2(b), which states that “Development is permitted by Class B subject to the following conditions … (b) 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: 


“The Council’s reason for refusing the application states that “The development described in the application is not lawful as the edge of the proposed rear dormer would extend across the full width of the roofspace and would therefore be closer than 20 cm from the eaves of the proposed gable end…”. This is inaccurate in that condition B.2 (b) requires the enlargement to be not less than 20 cm from the eaves of the original roof. I shall consider whether the condition would be breached by reference to the distance between the enlargement and the original roof eaves rather than the proposed gable end.  


The Council’s delegated report indicates that condition B.2(b) would not be met in that the dormer window extends the full width, whereas it should be 20 cm from the eaves of the gable end. The appellant submits that the Council’s measurement is incorrect in that it requires a set-back from the verge rather than from the eaves. The Oxford English dictionary defines the “eaves” as being the projecting edge of a roof which overhangs the side. It defines the “verge” as being the edge of the tiling projecting beyond the gable end of a roof. 


I concur with the appellant that there is no requirement for an enlargement to be set back from the verge merely from the eaves. However, the drawing 1008/LG1 shows that the original sloping hipped roof incorporates eaves which overhang the side elevation rather than a gable end verge. The scheme would result in the creation of a gable end to this side of the building with the new dormer extending as far as that new gable end. The GPDO states that the 20 cm should be measured “from” the eaves, but provides no further guidance as to how this should be done. Since the eaves includes the whole of the projecting edge of the roof, I consider that the measurement should be taken from the closest edge of the enlargement to the closest point of the projecting eaves and not just from the outer edge of the overhanging roof slope at the point furthest from the side elevation as shown on the appellant’s “as built” sketch. 


The drawing 1008/LG1 clearly shows that the dormer would extend the full width of the property. It would be positioned in direct alignment with the side elevation less than 20 cm from the eaves of the original hipped roof. It would not therefore comply with condition B.2 (b), so it would not be permitted development under the GPDO. This failure to comply with condition B.2 (b) cannot be dismissed as “minimal” as suggested by the appellant, and, in any event, the GPDO does not permit a flexible approach to such matters.” 


Main Conclusions: 


·       For the purposes of the 20cm set back, the term “eaves” applies to all of the section of the roof overhanging the wall, and not just to the outer edge of this section. As such, the 20cm set back should be measured from the point where the vertical plane of the wall meets the slope of the roof, rather than from the outer edge of the sloping roof.
[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: 

·       Drawings: 






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