The provisions of this chapter shall be known as the standards for required usable open space. The purpose of these provisions is to prescribe standards for the development and maintenance of open areas which serve the need for leisure, recreation, and space. These standards shall apply to all usable open space required by other provisions of the zoning regulations, except within the S-17 downtown residential open space combining zone. (Ord. 12343 § 3, 2001: prior planning code § 8300)

Each square foot of private usable open space conforming to the provisions of Section 17.126.040 shall be considered equivalent to two square feet of required group usable open space and may be so substituted, subject to any minimum requirements for actual group space prescribed in the applicable individual zone regulations. (Prior planning code § 8301)

(See illustration I-22.) All required group usable open space shall be permanently maintained, shall be located on the same lot as the living units it serves, and shall conform to the following standards:
A. Usability. A surface shall be provided which prevents dust and allows convenient use for outdoor activities. Such surface shall be any practicable combination of lawn, garden, flagstone, wood planking, concrete, asphalt, or other serviceable, dustfree surfacing. Slope shall not exceed ten percent. Off-street parking and loading areas, driveways, and service areas shall not be counted as usable open space. Adequate safety railings or other protective devices shall be erected wherever necessary for space on a roof, but shall not be more than four feet high.
B. Location. The space may be located anywhere on the lot within twenty (20) feet of the living units served, except that not more than twenty (20) percent of the required area shall be located on the roof of any building other than an attached garage or carport, with the exception of property located within the S-15 zone where the space may be located anywhere on the lot and may be located entirely on the roof of any building on the site.
C. Size and Shape. An area of contiguous space shall be of such size and shape that a rectangle inscribed within it shall have no dimension less than fifteen (15) feet. When space is located on a roof, the area occupied by vents or other structures which do not enhance usability of the space shall not be counted toward the above dimension.
D. Accessibility. The space shall be accessible to all the living units on the lot. It shall be served by any stairway or other accessway qualifying under the Oakland Building Code as an egress facility from a habitable room.
E. Openness. There shall be no obstructions above the space except for devices to enhance its usability.
F. Enclosure. Ground-level space shall be screened from abutting lots, streets, alleys, and paths, and abutting private ways described in Section 17.106.020, by a building wall, by dense landscaping not less than three and one-half feet high and not less than three feet wide, or by a solid or grille, lumber or masonry fence or wall not less than three and one-half feet high, subject to the standards for required landscaping and screening in Chapter 17.124 and the exceptions stated in said chapter. Fences and walls shall not be so constructed as to interfere with the access required by applicable fire prevention regulations. (Ord. 11892 § 20, 1996; prior planning code § 8310)

(See illustration I-22.) All required private usable open space shall be permanently maintained; shall be located, except as otherwise provided in subsection B of this section, on the same lot as the living unit it serves; and shall conform to the following standards:
A. Usability. A surface shall be provided which prevents dust and allows convenient use for outdoor activities. Such surface shall be any practicable combination of lawn, garden, flagstone, wood planking, concrete, asphalt, or other serviceable, dustfree surfacing. Slope shall not exceed ten percent. Off-street parking and loading areas, driveways, and service areas shall not be counted as usable open space. Adequate safety railings or other protective devices shall be erected wherever necessary for space on a roof or balcony, but shall not be more than four feet high.
B. Location. The space may be located anywhere on the lot, except that ground-level space shall not be located in a required minimum front yard and except that above-ground-level space shall not be located within five feet of an interior side lot line. Above-ground-level space may be counted even though it projects beyond a street line. All spaces shall be adjacent to, and not more than four feet above or below the floor level of, the living unit served.
C. Size and Shape. An area of contiguous ground-level space shall be of such size and shape that a rectangle inscribed within it shall have no dimension less than ten feet. An area of above-ground-level space shall be of such size and shape that a rectangle inscribed within it shall have no dimension less than five feet. When space is located on a roof, the area occupied by vents or other structures which do not enhance usability of the space shall not be counted toward the above dimension.
D. Accessibility. The space shall be accessible to only one living unit by a doorway to a habitable room or hallway.
E. Openness. There shall be no obstructions over ground-level space except for devices to enhance its usability and except that not more than fifty (50) percent of the space may be covered by a private balcony projecting from a higher story. Above-ground-level space shall have at least one exterior side open and unobstructed, except for incidental railings or balustrades, for eight feet above its floor level.
F. Enclosure. Ground-level space shall be screened from abutting lots, streets, alleys, and paths, from abutting private ways described in Section 17.106.020, and from other areas on the same lot by a building wall, by dense landscaping not less than five and one-half feet high and not less than three feet wide, or by a solid or grille, lumber or masonry fence or wall not less than five and one-half feet high, subject to the standards for required landscaping and screening in Chapter 17.124 and the exceptions stated in said chapter. However, when such screening would impair a beneficial outward and open orientation or view, with no building located opposite and within fifty (50) feet from such required screening, as measured perpendicularly therefrom in a horizontal plane, the above prescribed height may be reduced to three and one-half feet. Fences and walls shall not be so constructed as to interfere with the access required by applicable fire prevention regulations. (Prior planning code § 8320)

Every plaza required for Nonresidential Facilities shall be permanently maintained, shall be located on the same lot as the facilities for which it is provided, and shall conform to the following standards:
A. Usability. The plaza shall have an appropriate dustfree surface, and shall be suitable for walking, sitting, and similar activities. Off-street parking and loading areas, driveways, and service areas shall not be counted as plazas. At least twenty-five (25) percent of the plaza area shall be occupied by planting, sculpture, pools, or similar features.
B. Location and Visibility. The plaza shall be located not more than five feet above the sidewalk of the abutting street. It shall be clearly visible from the sidewalk.
C. Size and Shape. The plaza shall be of such size and shape that a rectangle inscribed within it shall have no dimension less than thirty (30) feet.
D. Accessibility. The plaza shall be directly and conveniently accessible to the general public during all business hours common in the area.
E. Openness. There shall be no obstructions above the plaza except for awnings, trellises, or similar devices to enhance its usability. (Prior planning code § 8335)