Domestic extension exemption

[Jimjim]

Ok,
I think I know the basics as Ive read the leaflets. Hoping to start a little extension to rear of the house.
Its aboout 20 sq.m. and no previous extensions all on ground floor.
same wall height as rest of house with no gables.
Lots of free space still remaining in back garden.
My main query is relating to distances required from boundary for exempt development & additionally, distances required from boundary for windows facing the neighbours house. Im alittle confused by this. A builder friend said I need to keep any window facing the boundary 3m back. I dont see this mentioned in the planning leaflets though.
So if someone could clear this up - How close can I build a single storey extension to neighbours boundary without planning if no windows & also if there are windows?

Thanks

[DOC]

3 metres back? Window facing boundary at ground floor can be 1 metre from the boundary it faces (but no less than 1 metre). With regard to building walls (without windows) you can build these right up to the boundary (or on the boundary with your neighbours consent).

[onq]

Your oddly chosen description of the 3 metre back issue and "all on the ground floor" intrigues me.
Have you recently opened a window on an upper floor within 3 metres of the boundary without permission?

If not, carry on; -

If you build a flat roof extension with parapet walls onto a bungalow with a pitched roof and eaves it may not be considered exempt - eaves height is just one issue, materials are another.
Also building to the rear on the shared boundary with a semi-D is a whole other world of uncertainty and grief at the moment.

Suggestion; -

Draw it up and talk to the planner.
Better still seek a Section 5 Declaration.
Although even the planners can get it wrong.

ONQ.