Told cant extend any further

We live in a 1930's semi detached, that was extended 17 years ago (before we moved in), full width ground floor (out by 3.6m) and half with 1st floor (the side not attached to the neighbour)

Neighbours house also has a 3.6m deep, single story extension with a flat roof. No 1st floor extension.

I went to the planning dept this week to ask (with crudely drawn sketches) if we could extend a further 3.4m out, single story only. Added to the existing extension, so the ground floor addition totals 7m from original house. I know would have to go through formal planning application as its over the permitted 6m for semi detached.

Was told no, because the proposed extension would block light for the neighbours back windows on their extension, does this sound right please?

Never been to planning dept before so didnt want to argue, or set off on the wrong foot, but is that a definite 'no'?

Wanted to know before I got proper drawings drawn up and submitted, so not to waste a load of money

Surely any single story extension that protrudes further than the adjoining house, could potentially block light to an extent??

Knock the extension down and build a new one up to 6 or 8m out under the prior notification scheme.

Extend out but design it so it does not impact ther neighbours windows.

Get someone out to advise you what you can actually do. Don't rely on a chat with the council. You need to know the council's actual planning policies, it's not a case of blocking light.

Thanks Woody, hadn’t thought of the permitted 6m rule for semi-detached..

I think I will get someone out to look at it properly and see if there’s a way around designing it so it can be a total of 7m from existing house, or is the extra 1m potentially not worth the hassle of applying for full permission?

It seems that this "blocking light" is actually an interpretation of the 45° rule - an imaginary line from the centre of the neighbour's nearest window.

If so the options are to step back or splay the corner of the extension on the one side, so that it's not built past the 45° line.

Have a look at your council's home extension guidelines for details.

Hi woody
Had a look on my local council website EFDC (Epping Forest distric Council) but no information that I could find on the rule. Ive since been told the 45 degree rule only applies to a habitable room. The neighbours window (its actually an old set of sliding doors about 1.5m in width) thats an extension to the living room, that houses a dining table. Not sure if that helps?

Well, a dining room is a habitable room.

If your neighbours already have a 3.6m ground floor extension, a further single-storey extension on your property should not necessarily be ruled out, as you are both extended rearwards to the same line.
Most councils have policy guidelines which set, among other limits, how far out you can extend to the rear; 3m is a common limit.
If you could live with 3m rather than 3.6m, there may be no valid reason the council could refuse planning permission (unless other factors such as over-development etc are relevant).