do I need planning permission?

[richancient]

I have an existing brick outbuilding being used as a shed currently.I am wanting to convert to a room for an elderly relative to use and wish to add a bathroom etc.Power and water already go to this outbuilding.Do I need planning permission?

 

[^woody^]

Do you mean a self-contained granny flat or just a bedroom and en-suite?

And is it attached to the main building?