Exterior floor area

exterior_floor_area – Used to calculate envelope_UA.

Synopsis
module residential; class house { double exterior_floor_area [ sf ] ; }

Remarks
This is an automatically calculated value, not a variable that the user may set.

It is calculated by:

exterior_floor_area = floor_area * exterior_floor_fraction / number_of_stories

Default
Using all default values:

$$2500\text{ft}^2 \cdot \frac{1}{1} = 2500\text{ft}^2$$

Therefore the default exterior_floor_area is 2500 square feet, which equals the default floor_area.