Rules for building retaining walls in required yards

(a) Retaining walls containing a fill within required yards shall not exceed a height of 6 feet, measured from existing or finished grade, whichever is lower, to the top of the wall along the exposed face of the wall. Heights of terraced walls or combinations of retaining walls shall be measured combining all walls located in the required yard (see Figures 21-4.2(A) and (B) ). (b) A retaining wall that protects a cut below the existing grade may be constructed within a required yard, up to the height of the cut. There shall be no height limit for retaining walls that protect a cut; provided that a retaining wall that protects a cut and contains fill shall not exceed a total of 6 feet in height measured from the intersection of the wall and the existing or finished grade, whichever is lower, to the top of the wall along the exposed face of the wall. (c) A safety railing may be erected on top of any retaining wall within a required yard. If the safety railing is generally constructed of a different material than the retaining wall, and is open at intervals so as not to be capable of retaining earth, it shall not exceed a height of 6 feet above the retaining wall. (d) Safety railing or fences constructed of the same materials as the retaining wall shall not exceed a total combined height of 6 feet measured from the finished grade along the exposed face of the wall. Additional fence height of different material not capable of retaining material may be erected, not to exceed a height of 6 feet measured from the finished grade of the retained material (see Figure 21-4.2(B) ). FIGURE 21-4.2(A) RETAINING WALLS FIGURE 21-4.2(B) RETAINING WALLS