I would like to build an outbuilding at the bottom of my garden, for general multi use (but not as a self contained living accommodation). I have looked on line and carried out some research relating to "Permitted Development". I have previously built above an existing garage which was attached to the side of my house with a 1st floor bedroom and on-suite. In addition I have a kitchen extension. As I have built above a garage (which has been rebuilt to the 1st floor) would this count towards the permitted allowance (which I believe as not exceeding 50%)? Just wanted to know this before I contact our local planning department. Any information would be most appreciated.