open-air ground floor
A building ground level with at least half its footprint unenclosed beneath upper floors or a roof.
A building has an open-air ground floor when at least 50% of the building's footprint area at ground level is not enclosed. This unenclosed space must either be overhung by the floors or roof above, or covered with floors or a roof supported on columns or pilotis.
The unenclosed area lies beneath the building, either under an overhang or between supports carrying the floors or roof. An uncovered outdoor area beside the building is outside this footprint-based measurement.
The threshold includes exactly 50 percent of the footprint. A small covered entrance opening alone does not establish an open-air ground floor when the remaining enclosed portion leaves less than half the footprint open.
