ask us a question on permitted development           Permitted Development England
How to build a home extension  without Planning Permission using your PD rights - Oct. 1st 2008



Home Page About Us FAQ Advertise on this site Disclaimer Privacy Contact Us Site Map

Appeal Decision 9 - Certificate of Lawful Development.


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

July 2009 - Code a00009  


Summary of Case (appeals dismissed): 


The left-hand side of number 20 is not joined to any other property. 

The right-hand side of number 20 is fully joined to the left-hand side of number 18. 

Number 18 and 16 are angled, such that the right-hand side of number 18 is not joined to the left-hand side of number 16 at the front, but these sides are joined at the rear by an original two storey block with a common party wall.

The key question was whether number 18 and 20 each constitutes a terrace house (in which case the 40m3 limit of Class B, part B.1(c) applies) or a semi-detached house (in which case the 50m3 limit of Class B, part B.1(c) applies). 


The Inspector noted the definition of “terrace house” at the end of Part 1, which states:

““terrace house” means a dwellinghouse situated in a row of three or more dwellinghouses used or designed for use as single dwellings, where—
(a) it shares a party wall with, or has a main wall adjoining the main wall of, the dwellinghouse on either side; or
(b) if it is at the end of a row, it shares a party wall with or has a main wall adjoining the main wall of a dwellinghouse which fulfils the requirements of sub-paragraph (a).”

The Inspector noted that from the front number 18 and 20 appear to be semi-detached houses, that they were described in the sale as such, and that the main side walls of number 18 and 16 are separate and at an angle.  However, he also notes that number 18 and 16 are joined by a two storey block towards the rear part of their sides, that this block is original, and that it is of a size substantial enough to prevent it being regarded as a trivial or insignificant feature.  The Inspector concludes that the existence of this block is sufficient for the each of numbers 20, 18, and 16 to be classed as a “terrace house”. 


Main Conclusions: 


·       For the purposes of Class B, part B.1(c), where two properties are angled, such that their side walls are separated at the front but are joined towards the rear by a common party wall (in this case by an original two storey block of a size considered to be not trivial or insignificant) then this can be sufficient for the properties to be considered as sharing a party wall for the purposes of the definition of a “terrace house”.
[Relevant to: ““Detached dwellinghouse” (versus “any other dwellinghouse”) and “terrace house” (versus “in any other case””, “A.1(e)”, “B.1(c), “Interpretation I”]. 


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


·       Appeal Decision Notice: 

·       Drawings for 18: 

·       Drawings for 20: 




Download documents and diagrams of useful

Permitted Development information

permitted development documents download


 Appeal Decisions