Mostafa Tavengar
Hi, generally you will not need planning permission, although if the work you are planning requires some structural changes then you will need a building control notice, but these are relatively easy to get, and can even be applied for retrospectively if needs be. The fee will probably be between £200 and £400 but, in my opinion, this is money well spent as they will inspect your job before and after and tell you what size beams you need etc. They will then sign off the work and you will be able to put the paperwork with your deeds, adding value to your property. Your builder should be able to help you with all of this but, for now, don't worry, it sounds like a relatively simple job, I am sure you will be fine. Good luck with your build!
