We have put a room on the back of our house. When we opened up the wall we found that the old floor is 1/4" higher than the new. The new room is a kitchen, but we would like to put t&g hardwood in both the new kitchen and the old room (dining room). would we be better off adding 1/4" underlay in the new rooms (26x30), or would we be better off replacing our t&g subfloor in the dining room (14x11), or should we put in a transition piece between the two, or is there a better idea?