Already got conservatory - can we still have extension under permitted development?

[Berrie]

We already have a large conservatory and want an extension under the temporarily extended permitted development rules. I was wondering whether the existing conservatory uses up the allocation at all. I tried ringing but the lad who answered couldn't understand what I meant and asked me to put it in an email. The email reply says they will get back to me within 5 working days but that I can telephone if I want! Thought I'd try Mumsnet instead!

Bump

have you tried asking the local planning office?

Yes - like I said, I rang them.

The only element of permitted development that has a volume limit is roof alterations such as dormer windows. There is no cumulative limit on other types of extensions as long as no more than half the original plot is not covered. If you can get a second extension to fulfil all the pd requirements then you can do it. The Planning Portal has some helpful advice details here

Went through this scenario a few months ago. We had a semi with a conservatory that extended from the ORIGINAL wall (built 1930) by about 2 metres.

I can't recall the 'exact' permitted measurements pre and post 'relaxation' dimensions but the gist is this - for us the relaxed new rules allowed us to build up to 3 metres out without consulting neighbours and 3-6 metres with neighbour consultation - (no planning permission required)

But the measurements can only be from the ORIGINAL exterior wall of your house NOT taken from the existing conservatory (unless that was part of the original house structure - if built before 1948 I think)

So basically yes - the existing conservatory does use up the allocation as all measuremenst must be taken from the original exterior wall

Thanks for your help - that's good then.
We will need to do neighbour consultation and I don't think they will like it. I wouldn't. Our gardens slope down so it would end up being rather imposing when they stood in their garden. I don't think we would go ahead if they were really unhappy but we might be able to compromise by stepping the bottom half of it down...don't know.

the conservatory only needs to be taken into account if the new extension projects from it. If the new extension is completely separate from the conservatory, attached to the original house it shouldn't have an impact.

There is a document you can download,
'Permitted development : Technical guidance'
It shows lots of different pictorial examples including existing extensions, and size limits etc.
Also distance from the boundary line has an affect on what you can do.