Interior Area is a per floor calculation, made by measuring to the inside surface of the exterior walls. The footprint of all interior walls and staircases is typically included.
Excluded Area is a sum of the area of all rooms (measured to the inside surface of room walls) that are excluded from the Interior Area for a floor and the footprint of corresponding walls. Prescribed area exclusions can vary from region to region. Examples of exclusions are spaces open to below, garages cold cellars, crawl and reduced height spaces.
Exterior Wall Footprint is the sum of the estimated area of the perimeter wall segments bounding both Interior and Excluded Areas.
Exterior Area is a per floor calculation, made by measuring to the outside surface of the exterior walls and is represented by the sum of the Interior Area and the Exterior Wall Footprint.
Grade is the ground level at the perimeter of the exterior finished surface of a house. A floor is considered to be above grade if its floor level is everywhere above grade.
