The following 4 automatic properties provide data for wall area calculations:
- Area—Right Gross
- Area—Right Net
- Area—Left Gross
- Area—Left Net
The right and left sides of a wall are determined as if you were standing on the start point of the wall and facing the endpoint. Gross area is the area of one side without allowing for holes for openings such as doors and windows. Net Area is the area of one side of a wall after holes are cut for openings. Gross Area might be used to determine the quantity of gypsum board needed for a wall, while Net Area might be used to determine the quantity of brick.
Danger: The area of a wall is determined by adding the union of the wall components (not including body modifiers or interferences) to the area of all faces that point to the right (for right areas) or the left (for left areas). If a particular wall style has multiple components with air space between them, the wall area may not be reported as expected. For example, a wall typically used in construction has a brick exterior, an air space, and a CMU interior. A style defined for this wall might have a component for the brick and a component for the CMU, but no component for the air space. If the wall was drawn with the brick on the left side, the wall area computed for the right side would include the right face of the CMU as well as the right face of the brick. The area reported would be twice the actual area. To avoid this situation, create components for interior air spaces in wall styles, so that no interior faces exist when the wall components are union.
The shape of a wall can be modified by adding or subtracting body modifiers. Automatically calculating appropriate areas for every possible wall shape is practically impossible. Because of this, body modifiers and interferences are not currently included in wall area calculations. Wall areas for unusually shaped walls must be computed manually.