Is this considered Permitted Development

[Dedekind]

Hello

We are In the process of planning a single storey rear extension. We have one already 1.5m long and the plan is to demolish it and build a longer 3m extension.

All people told me this would be PD but my engineer has the view that most likely we need planning permission. The reason is that the garden is angled (see picture), and if we want to follow that boundary line then we are extending beyond the original side wall -- meaning that it will not be considered PD.

Is this really the case?

I was checking on planningportal.co.uk where it says:

* The term "original house" means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so

I can't guarantee my extension was there on 1 July 1948, but it was definitely there in 1949 (from the plans in the land registry). If it's considered part of the original house, what is the "original side wall" then?

Picture:
https://ibb.co/jTwg58F

 

[tony1851]

It would need planning permission because, at its widest point, your extension would appear to extend beyond an original side wall and be more than half the width of the house.

 

[jeds]

Your proposal is not PD because the width at the widest point would be more than half the width of the house.

 

[jeds]

Beat me to it!

 

[Dedekind]

Hm understand but if the angled old extension is considered as "original house", what is the side wall that needs to be considered? Surely the small angled wall on the existing extension is also an "original side wall"? Meaning that one should be able to continue that line?

 

[tony1851]

Beat me to it!

 

[tony1851]

Hm understand but if the angled old extension is considered as "original house", what is the side wall that needs to be considered? Surely the small angled wall on the existing extension is also an "original side wall"? Meaning that one should be able to continue that line?

To know for certain, you would best be providing a scaled drawing, or one with measurements.
See attached; even assuming the first extension was original (or pre - '48) if x is greater than 1/2 y, then you would need planning permission

 

[Dedekind]

Ah I see. Yeah in your picture x is larger than y/2 (only by a little less than 1m..).

I was thinking differently: if the extension is original, one could argue that the diagonal wall is original and one would be able to extend following that line (similar to what would happen in a rectangular housr: you would extend following the line of the side wall). But if that's not the case then I will just go PP.

Any reason why this can be rejected?

 

[Dedekind]

How about if we do a rectangular extension starting on the current extension rear wall? I.e. we keep current extension and the new extension does not follow the diagonal boundary, rather it just goes 90 degree from that point.

Would this be PD?