For townhouses and garden apartments, at least 10% of the site area shall consist of landscaped open space exclusive of building area, parking area, and access drives. For garden apartments, at least 5% of the site area (which may be included in the foregoing 10%) shall be common open space developed for active or passive recreation use of the residents of the project, including sitting areas, play areas, and the like; for townhouses, at least 10% of the site area shall be so developed, but may include individual patios.