What size will the room be?
The attic room is often the biggest room in the house. Even in the smallest of houses it will be far bigger than the boxroom. For a rough guide, measure the distance from gable wall to party wall; this is the length of your available space provided your roof is not “hipped”. Now measure the distance from front to back and divide by two; that is the width of your available space. (This is generally accurate, but not always.