maximum sq footage before planning is needed

[slap2011]

want to put conservatory on back of house can we do this without planning permision and what is the max sq footage you can have before you have to apply for planning

[welsh brickie]

you always need planning, always contact the planning department before starting work,if you dont and a neighbour complains you may have to take it down.
Normally the planning department will say go ahead anyway but its always best to check.