“Common open space” means an area on the ground, balcony, or deck that is available and accessible to the occupants of a building or building site for the purposes of active and/or passive recreation. This area includes the aggregate area of ground level areas, side and rear yards, (but not required front yards or exterior side yards), and patios, balconies and decks having a depth of not less than six feet and area of not less than sixty square feet. This area is exclusive of any area having a slope greater than ten percent, driveways, area for off-street parking and services, and ground level areas with a width of less than six feet or maximum dimension of under ten feet. Notwithstanding the general exclusion of driveways, on project sites with an average width of less than one hundred feet, the planning commission or the city council on appeal may allow minor driveways as defined in Section 17.66.020 to be included within the definition of common open space. In multifamily residential developments of at least twenty units, indoor spaces of not less than three hundred square feet, designed and used for recreational purposes, can be included as part of a project’s required common open space. (Ord. 2020-07 § 2, 2020; Ord. 2006-03 § 1 (Exh. A), 2006; Ord. 2005-10 § 1 (Exh. A), 2005; Zoning Ordinance dated 7/94, 1994)