Extending my garage

Hi i was wondering if anyone can help.

I have a large single concrete garage that i want to double in size within my land.
I use this garage for business purposes and i am wondering if i need planning permission in order to do so.It is well hidden and at the end of a 50 metre driveway and completely hidden by trees and shrubbery.

I was thinking of building the extension with breezeblocks and then fitting a new apex roof over both.Any advice anyone?

if it is above 30m2 then yes to p.p.

i would not bother extending onto the prefab at all.

demolish the concrete garage and build from new. the problems you will encounter trying to build a conventional roof onto an unconventional mish- mash of buildings will be a nightmare.