Extension and 'right to light'

[Mallowmarshmallow]

Both ourselves and our attached neighbours have approx three metre single storey extensions. We would like to extend on top of ours but have mixed feedback on whether we will be able to extend all the way across (sideways, towards the neighbours) or if we will only be able to use the outer half for the extension.

We both have two bedroom windows upstairs so if we extend all the way out it would affect the lighting into their bedroom nearest our house. Does anyone know if there is a 'right to light' element that would prevent us from extending all the way across?

Obviously, I will get plans drawn up and employ an appropriate surveyor to advise but I wondered if anyone had any knowledge/experience they could share before I start the process in earnest.

I have just been looking at this as we are looking to object to a planning application where somebody wants to build a house directly overlooking our garden. This is the information I've found online summarising most common (valid) reasons to object:
*
• Adverse effect on the residential amenity of neighbours, by reason of (among other factors) noise, disturbance, overlooking, loss of privacy, overshadowing, etc. [but note that this does not include noise or disturbance arising from the actual execution of the works, which will not be taken into account, except possibly in relation to conditions that may be imposed on the planning permission,dealing with hours and methods of working, etc. during the development]
• Unacceptably high density / over-development of the site, especially if it involves loss of garden land or the open aspect of the neighbourhood (so-called ‘garden grabbing’)
• Visual impact of the development
• Effect of the development on the character of the neighbourhood
• Design (including bulk and massing, detailing and materials, if these form part of the application)
• The proposed development is over-bearing, out-of-scale or out of character in terms of its appearance compared with existing development in the vicinity
• The loss of existing views from neighbouring properties would adversely affect the residential amenity of neighbouring owners
• [If in a Conservation Area, adverse effect of the development on the character and appearance of the Conservation Area]
• [If near a Listed Building, adverse effect of the development on the setting of the Listed Building.]
• The development would adversely affect highway safety or the convenience of road users [but only if there is technical evidence to back up such a claim].

I'm not sure the right of light argument in itself would necessarily scupper yours but that's only from my neighbour's objection being rejected on similar grounds (it was tenuous).

Does your local council have a guide (there's probably a proper title) on planning applications? I know the two London boroughs we've lived in do and they had good examples of what would and would not be accepted.

Have any other houses in the area done anything similar? You could look at their planning applications online.

Look up the 45 degree rule, OP. It really does depend on position of windows etc. Has anyone extended like how you'd like along the street?

Are you semi detached, and wanting to extend all the way double storey to the boundary with your neighbour?

If that's correct, we did a double storey extension a while ago and had to come in 2m on the upper storey from neighbours boundary.

Have just checked our LEAs SPD4, knew there was a reason we had to come in 2m from boundary but couldnt remember why!

It says double storey rear extensions should only project 1.5m where they are close to a boundary (terraced/semi detached) but if they are set in from the boundary, they can project for the same distance as they're set in by, plus the 1.5m. So, if you wanted to go right up to the boundary line, you'd only be able to extend 1.5m. That's obviously why we set it in 2m from the neighbour, so we could go out 3.5m (1.5m plus the 2m) so it was in line with what we wanted to do downstairs!

Ours is something like this - very typical in the area

Judging by what is being approved around us I doubt very much they would refuse due to light in a bedroom. In fact if you check the updated rules coming out you might not even need planning, just building regs

Our house has an upstairs extension.it's a semi. It is only extended on one side, so the rear bedroom which is attached to the neighbours has no extension on from it but the other back room does. I don't believe planning would have been granted otherwise

Simplest and cheapest appraoch is to ask for a consultation with the local planning dept.