the galss cannot be made breakable, but can be made transparent
turn the glass into a func_rotating with the same properties as the rotating room (sound properties are non essential) and most importantly, make the origin bush of the rotating glass at the same point as the origin brush of the room. now set the render properties of the 'glass' and make sure the room and 'glass' have the same name, so when you target them they stop in uniform and make sure they spin the same way!