For permitted residential uses, the provisions of Section 23-311 (Permitted obstructions in all yards, courts and open areas) shall apply with the following modifications:

(a)    open accessory off-street parking spaces shall not be located within a front yard unless such spaces are located in a permitted side lot ribbon;

(b)    three-foot overhangs in a required front yard in R4 or R5 Districts shall not be permitted.