The Plan Store

How is the living square footage (or conditioned space) on a floor plan calculated?

Generally, square footage calculations of conditioned space are made from the outside the exterior frame walls and do not include unconditioned space, which is not heated and / or cooled, such as garages, basements, attics, and large storage areas. We include two story vaulted areas only once in the calculations of the first floor. Stairs are counted once. The second story is calculated in the same fashion as the first story. Stairs are counted once. The second story is calculated in the same fashion as the first story. Interior balconies and open walkways in two story and vaulted areas are included in square footage. Porches, decks, and balconies which are outside of the exterior walls are not included in either the conditioned or unconditioned space calculations.