Do Finished First Floor Elevations Include Basements?
Regulations require the ground to slope away from the foundation walls, usually at 5 percent -- 6 inches drop over 10 horizontal feet -- to keep water away from the foundation. This is referred to as positive drainage. The ground around the structure is lower than the foundation wall, or slab-on-grade, by a specified dimension, and runoff is directed to surface or subsurface drainage systems that convey it to a safe discharge point.
