Multifamily developments, including those in the city's commercial districts, are exempt from this chapter, except they must set aside a minimum of fifteen percent of the gross site area for recreation use. Recreation use must be designed to serve as a centralized recreational facility, not merely leftover space along the edges of required yards and standard landscaping. This area may include open space areas, play structures, sport courts, plazas, indoor or outdoor recreational facilities, trails and paths, community gardens or other similar facilities. Open space/recreation areas do not include the following: parking lots, driveways, private/public street rights-of-way, required storage areas.