Permitted Development 4m rear extension

[caterhamboy]

Hi, there seems to be so much conflicting advice on the internet.

I plan to build a 4m rear single storey extension on my 1930's semi detached, neighbours are fine with this. Do i need to go through consultation scheme ?

Would it be correct that if it was 3m i wouldn't, but 3-6 metres i do?

Thanks

[Equus]

Is your house detached, or semi/terrace?

If detached (and subject to the other PD rules), you can go to 4m. with 'normal' PD, and 8 metres with a Prior Approval application.

If non-detached, the limits are 3m. and 6m. respectively.

[caterhamboy]

Thanks Equus,

Yes it's a semi detached, on some sites there seemed to information saying that it had changed to 4m.

So i need to a prior notice application?

[Equus]

caterhamboy said:

Yes it's a semi detached, on some sites there seemed to information saying that it had changed to 4m.

So i need to a prior notice application?

It's news to me (and the Government's own Planning Portal), if it has... but anything is possible with the blizzard of ill-conceived tinkering that Boris and Bobby have been bombarding us with, lately - I genuinely lost count of the number of changes to Permitted Development rules, last year. They obviously didn't have enough to do with their time - the Devil makes work for Idle hands, and all that. Maybe we needed something like withdrawing from the EU or a major global epidemic to keep them more usefully occupied?

But yes, you'll need a Prior Approval with Neighbour Consultation - and if the rules had changed such that this wasn't necessary, the LPA would tell you so.

[Wombat3]

Equus is the expert on these things but as I understood it basically your PD rights are 3m on a semi but , with the filling out of the correct form(s) this can be extended to 6m.

(4m & 8m on a detached house)

Question: is the back of your house flat? It may sound like an odd question but if its not then you can get caught by having your extension classified as a "side and rear" extension (despite the fact that its nowhere near the side of the house!)

In which case you need planning permission (ask me how I know! )

[Equus]

Wombat3 said:

Equus is the expert on these things but as I understood it basically your PD rights are 3m on a semi but , with the filling out of the correct form(s) this can be extended to 6m.

(4m & 8m on a detached house)

Correct... which is what I said above (or tried to!).

Also valid observation about the side/rear extension issue with rear projections (and remember that PD rights are measured from the original dwelling, so previous extensions don't count when you're measuring the projection).

But if you're making an application with drawings, your plans drawer and/or the LPA should pick up any issues like this.

[caterhamboy]

Back of the house has little coal shed (1.8m*2.5m) single storey that was original, and the kitchen has been knocked into at some point.

Would this be original back of house?

[Equus]

Yes, and as Wombat has said, the allowable projection is therefore measured from the main back wall, not the back of the original coalshed outshut.

See this diagram (which is from the Permitted Development Technical Guide):

[caterhamboy]

Ok thanks, Was planing of building without any plans. just standard extension with building control. In the trades so got different people lined up to do foundations etc.

[Equus]

caterhamboy said:

Was planing of building without any plans.

Not possible. You'll need drawings for the Prior Approval process.

[caterhamboy]

Yes, will look into getting some drawings done, or just build to 3m.

It will be on a raised patio so 4m was the max i wanted to without having to extend all of that, which would have still left about 3m of patio. it drops off about 6ft so fairly big job.

Edited by caterhamboy on Thursday 7th January 13:05

[Equus]

caterhamboy said:

It will be on a raised patio ...

Not if it's Permitted Development, it won't!

the GPDO said:

Development is not not permitted by Class A if ...it would consist of or include—

(i)the construction or provision of a verandah, balcony or raised platform

[Wombat3]

Equus said:

Yes, and as Wombat has said, the allowable projection is therefore measured from the main back wall, not the back of the original coalshed outshut.

See this diagram (which is from the Permitted Development Technical Guide):

The point I was also making was that if you wanted to build an extension that covered just A & B in the 2nd drawing above, even if it is still only 3m out from B it would be a side & rear extension (and therefore require planning) because the wall between A & B is a side wall

[Equus]

Wombat3 said:

The point I was also making was that if you wanted to build an extension that covered just A & B in the 2nd drawing above, even if it is still only 3m out from B it would be a side & rear extension (and therefore require planning) because the wall between A & B is a side wall

Yes, sorry... agreed, sort of... but only if it is also greater than half the width of the original house.

If it's less than half the width, you can still go out to the 3/6m. or 4/8m. limit to the rear, measured from the deepest point on the back wall.

See page 23 of the Technical Guide.

[Wombat3]

Equus said:

Wombat3 said:

The point I was also making was that if you wanted to build an extension that covered just A & B in the 2nd drawing above, even if it is still only 3m out from B it would be a side & rear extension (and therefore require planning) because the wall between A & B is a side wall

Yes, sorry... agreed, sort of... but only if it is also greater than half the width of the original house.

If it's less than half the width, you can still go out to the 3/6m. or 4/8m. limit to the rear, measured from the deepest point on the back wall.

See page 23 of the Technical Guide.

I'm sure that's right but to add to it, where I got caught was (using the above diagram) there was already an extension on part of it & when I wanted to bring the next bit out slightly beyond that (even though the whole was less than 3M from the original line) they then looked at the two extensions as one and it fell into that "side & rear " trap. The newest part I was building was less than half the width of the house, but the two combined covers maybe 90% of it.