Restrictions on the use of open space for parking and driveways are set forth in this Section, in accordance with the provisions of Section 23-12 (Permitted Obstructions in Open Space).

(a)        In R1, R2, R3, R4-1, R4A and R4B Districts, driveways, private roads, open accessory off-street parking spaces, unenclosed accessory bicycle parking spaces or open accessory off-street loading berths may occupy no more than 50 percent of the lot area not covered by buildings containing residences;

(b)        In R4 Districts, except for R4-1, R4A and R4B Districts, and in R5 Districts, driveways, private roads, open accessory off-street parking spaces, unenclosed accessory bicycle parking spaces or open accessory off-street loading berths may occupy no more than 66 percent of the lot area not covered by buildings containing residences; and

(c)        In R6, R7, R8, R9 and R10 Districts without a letter suffix, driveways, private streets, open accessory off-street parking spaces, unenclosed accessory bicycle parking spaces or open accessory off-street loading berths may not use more than 50 percent of the required open space on any zoning lot. The provisions of this paragraph (c) shall not apply to Quality Housing buildings.