Building Piece Function Change

[Aurust]

Is it possible to change the function of an individual piece of an already built building. For example if I have a tower and a room that are built as the bailiff office in my manor can I change just the tower piece to the watchtower function without having to build a whole separate part of the manor building or deleting and rebuilding the same tower piece just designated as the watchtower function?

[Dietre]

yes there is a button next to the room name that looks like a gear. costs some gold to switch