do i need planning or building permission to convert the roof of my garage from a flat roof to a pitched one it is a free standing garage which stands within the boundery of my property
I dont know, but if you get in touch with your local council building regulations department, they should be able to tell you if you havent already tried this. Better to get the info from the horses mouth than rely on something a friend tells you.
You are going to have to ask the Development Control dept at your council because it is impossible to give you a definitive answer here. The likelihood is 'no', but if you live in a special area (like a Conservation Area), you might need PP.
Garages under 30 square metres external floor area do not fall under the remit of Building Control, so 'no' to that question, unless it is over that size.