Hi all,
In my opinion (and as stated by Tony) the single storey rear extension (i.e. directly to the side of the two-storey rear extension) would
not be PD.
There are two potential problems.
Firstly, it is
not possible as a single operation to erect an extension on the basis that part of it has been granted PP by the Council and the other part would be PD. I've seen 6 appeal decisions that have supported the above conclusion, and none that have contradicted it. An example of such an appeal decision is the following:
http://www.pcs.planningportal.gov.uk/pcsportal/ViewCase.asp?caseid=2169793&coid=2169792
In the example subject of this current thread, for the works not to be a "single operation", it would have been necessary for the two-storey rear extension to have been completed, then for a sufficient amount of time to have passed, and then for the single storey rear extension to have been started.
The above might sound very "artificial", but I'm afraid it's just the way that planning law currently works. A similar situation is that under Class E you can lawfully build an outbuilding that contains a gym, and then (say) a year later you can lawfully convert the gym to a bedroom, but if you build the outbuilding with a bedroom in the first place it will be unlawful.
Even if it was the case that the single storey rear extension was a separate operation to the two-storey rear extension, then in my opinion it would still not be PD because of the following second issue.
There have been a number of appeal decisions that have either stated or implied that the phrase
"the enlarged part of the dwellinghouse" not only applies to the proposed extension, but
also includes any previous extension (i.e. non-original part of the application site) to which the proposed extension would be attached. More specifically, I've seen 7 appeal decisions that have supported the above conclusion versus 4 that have contradicted it - so there's a degree of ambiguity, but the majority support this conclusion.
What the above conclusion means is that even if the single storey rear extension was a separate operation to the two-storey rear extension, when you try to assess the single storey rear extension against PD legislation you would actually have to assess the combination of
both extensions (because the
"enlarged part of the dwellinghouse" would be the combination of both extensions).
The point that Tony referred to about pages 26/27 of the DCLG "Technical Guidance" document (2010) isn't that the above conclusion is
stated by these pages, but that it's
implied by these pages. Basically, these pages deal with a different example where one extension has been built under PD, and then the owner tries to erect a second extension under PD that would be attached to the first extension. For such an example, these pages state that the combination of both extensions would fail the limits of Class A, which strongly implies that the phrase
"the enlarged part of the dwellinghouse" includes any previous extension (i.e. non-original part of the application site) to which the proposed extension would be attached (i.e. the same conclusion that's supported by the above 7 appeal decisions).
Hope the above helps,
Steve