Planning For An Extension

[bob561941]

What is the maximum square footage you can seek planning for that the local authority cannot refuse you. ?

[bednobs]

can't really understand your Q. if you have to apply for planning, they can ALWAYS refuse you (otherwise what would be the point of having to apply?)

[ubasses]

http://www.homebuilding.co.uk/advice/project-tips/planning-permission/no-planning

The above site gives you details of permitted development without planning permission. Remember you will still have to comply with building regs.