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Appeal Decision 25 - Certificate of Lawful Development.

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

September 2009 - Code a00025


Summary of Case (appeal dismissed): 


The property is a two-storey mid-terrace house, and the application was for a proposed rear dormer. The existing roof of the property has a main ridge-line with a raised parapet wall on either side. The flat roof of the proposed rear dormer would have been at the same height as the main ridge-line, and along the side edges of the flat roof of the dormer there would have been raised parapet walls at the same height as the raised parapet walls on the main roof.

The key issue was whether these new parapet walls, which would be at the same height as the existing parapet walls, would “exceed the height of the highest part of the existing roof”. It should be noted that this appeal was assessed against the previous GPDO; however this issue is still directly relevant to Class B, part B.1(a) of the amended GPDO, which states that “development is not permitted by Class B if … any part of the dwellinghouse would, as a result of the works, exceed the height of the highest part of the existing roof”.

The Inspector concluded that “the highest part of the existing roof” is the main ridge-line of the property, as formed by the ridge tiles along the apex at the join of the front and rear roof slopes. He stated that this phrase does not include such raised parapet walls, and does not apply to chimneys. 


Main Conclusions: 


·       For a property with a pitched or hipped roof, “the highest part of the existing roof” is the main ridge-line, and does not include raised parapet walls or chimneys.
[Relevant to: “Highest Part of the … Roof”, A.1(b), C.1(b), G.1(a), H.1(b)].


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


·       Appeal Decision Notice: 

·       Drawings: 







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