rear extension on semi detached house - neighbours' right to light etc

[CurlyhairedAssassin]

We want to build an extension on the back of our semi detached house. Both we and the adjoining neighbours use our back room facing the garden as a living room. The kitchen in both houses is next to the living room on the non-adjoining parts of each house, again facing out towards the back garden.

Hope you get the picture of layout etc. My question is, our adjoining neighbours have extended their kitchen previously so that their kitchen now projects out further than the original line of both houses. If WE extended on to our living room which adjoins the neighbours, then effectively THEIR non-extended living room would be set back on both sides - on one side by our extension and on the other side by their own kitchen extension.

Would we still be able to extend by the standard 3m or would they have a right to complain about lack of light even though part of the problem would be their own kitchen extension?

No, they would not win an objection - they have no right to light.

Unless this would actually attach to them when you would need a party wall agreement then you don't even have to inform them.

What way does you garden face and are you left or right side of the semi?

I'm not sure there really is a "right to light" but our neighbours (and plenty of others on the street) had similar (before we bought) and it was obviously approved.

Even if it doesn't attach, you may still need a PWA if your foundations will be lower than theirs and within 3 metres of their property. If it's a 30s semi, your new foundations will be lower.

No, you can extend up to 3m whatever they've done their side of the fence. But party wall agreement likely required for foundations anyway.

Thanks all for advice. Yes, I had already considered party wall agreement because of foundations. It is a 1930s semi.

Said: the back rooms face south so get plenty of light (part of the reason why we use this room as a living room and have our dining room in the front, as well as enjoying looking out to garden). As we look out of house towards back garden we are on the left side.

Thinking about it, they can't have been that bothered about light when they built their own extension as the late afternoon sun sets behind their kitchen extension so their living room must be in shadow a little bit.

Our ideal extension would be an L shape all along back of house and down the side a bit (currently got a jerry-built utility lean to affair added to back of equally jerry built garage!). Would involve demolition of craply built things and I think the L shape means that it will be wider than the permitted 50% of the original so would need planning permission I think. Not sure yet as haven't had any architects in and are still at the "thinking about different possibilities", "getting my head round planning rules" and "researching photos on Internet" stage!

Here's some useful links...

Planning & Building Regulations guidance here:

Permission

Also check Party Wall Act here:

PWA Guide

Contract suitable for small scale domestic projects:

Homeowners Contract

and, (here's the advertisement) if you want peace of mind, have a chat with a local Architect before doing anything...

Pendeen's Good Deed for fellow Architects

Best of luck :)