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Appeal Decision 206 - Certificate of Lawful Development.

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February 2011 - Code a00206


Summary of Case (appeal allowed): 


The property is a two-storey semi-detached house. The main roof is dual-pitched, with front and rear facing pitches and a gable end. The application was for a proposed two-storey rear extension. The roof of the proposed extension would be mono-pitched, with the pitch facing sideways towards the adjoining semi-detached property. The eaves of this mono-pitch roof (on the side nearest the adjoining semi-detached property) would be at height 3m. 


The first key issue was whether the proposed rear extension would be contrary to Class A, part A.1(i), which states that “Development is not permitted by Class A if … it would consist of or include … an alteration to any part of the roof of the dwellinghouse”. 


The Inspector stated the following: 


“The Council's case has expanded since it refused the application. Its decision said that, firstly, the proposal would include, but not consist of, an alteration to the dwellinghouse’s roof, so it could not benefit from permitted development rights in Classes A or B. The appellant did not contest this, and the Council cited an appeal decision [January 2010 - Code a00081] which held that an extension butting into an original roof did indeed involve an alteration to it. 


The decision went on to say that, in terms of Class C (which relates to other alterations to a roof) the proposal would protrude more than 150mm beyond the plane of the original roof, and so would not meet the limitation in C.1 (a). From this the Council concluded that it would require specific planning permission. 


However, subsequently the Dept of Communities and Local Government issued Technical Guidance on Permitted Development Rights for Householders (TG), to aid interpretation of recent changes to the GPDO. It advises that changes to a house’s roof are not permitted development under Class A, but may be under Class B or C. “For example, where a proposed two storey extension at the rear of a house has a roof that joins onto the main roof of the original house, the works will need to meet the requirements of both Class A (which covers the enlargement of the house) and Class C (which covers any alterations to the roof) in order to be permitted development”. 


As the appellant points out, the TG says in relation to the Council's point under Class C, “This limitation to projection from the roof plane should not be applied in cases where the roof of an extension to a house that is permitted development under Class A is joined to the roof of the original house. In such cases, the roof of the extension should not be considered as protruding from the original roof”. The Council's contention is therefore now contrary to the TG’s advice and so is not well-founded.” 


The second key issue was whether the proposals would be contrary to Class A, part A.1(g), which states that “Development is not permitted by Class A if … the enlarged part of the dwellinghouse would be within 2 metres of the boundary of the curtilage of the dwellinghouse, and the height of the eaves of the enlarged part would exceed 3 metres”. 


The Inspector stated the following: 


“The proposal would have only one eaves which would accord with this definition, and so is the only one to be assessed under A.1(g); the top of the monopitch would be a “ridge”, not an eaves.” 


Main Conclusions: 


·       Class A does permit an extension with a roof that would join onto the roof of the main house.
[Note: This would appear to contradict at least one other appeal decision – for further information see the entry in the “Reference Section” on “Interaction between Class A, Class B, and Class C”].
[Relevant to: “Interaction between Class A, Class B, and Class C”, Class A, A.1(i), Class B, B.1(c)].


·       For an extension with a pitched roof, the “eaves” of the extension are the lower end of the slope, and can not be taken to be the higher end (i.e. ridge-line) of the slope.
[Relevant to: “Eaves”, A.1(g), E.1(e)].


·       Where the roof of an extension would have a similar angle to the main roof, but would have a different orientation, it is possible for such an extension to comply with Class A, part A.3(c).
[Relevant to: A.3(c)].


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


·       Appeal Decision Notice: 

·       OS Map: 

·       Drawings: 




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