A grading permit is required any time land disturbance activities are occurring, except for the following: excavation below finish grade for basements, footings, swimming pools and septic systems; cemetery graves; refuse disposal; single family homes or duplexes located outside the HHOD (Hillside/Hilltop Overlay District), areas of 15% slope or greater, or floodplain zones; and building additions of less than 2000 square feet.