Change of use .... or not ?

[Pads]

Im considering buying a barn near my house which is currently used for storage of junk , parking of a tractor and car and a work room. I intend to use it for almost the same thing , parking the car, and as it has some land with it Im planning to use this as a veg garden , so would also use it as a potting shed and work room for my husband .

But I do intend to make a proper concreat floor and plaster the walls , maybe even create a messazine ( upper floor already there but rotted out. ) the stone walls and roof are sound ( maybe a little work required ) I will also change the large metal doors for 2 wooden garage doors . I wont need any extra windows or doors added as there are already enough. but may add a some sky lights.

I understand there is water and electric there already if I wanted to make these safer and add circuit boxes and a sink ( hubby a electrian with experiece of european electrics.) would i need to imform any one ? 

Can anyone tell me if this would require planning permission or change of use etc........ or anything else I might not of heard off?

Many Thanks