Level of required yards
Underlying yard regulations shall be modified to allow yards to be higher than curb level but in no event higher than flood-resistant construction elevation. In addition, the following regulations shall apply:
(a) in Residence Districts and C1 through C6 Districts, yards higher than curb level shall comply with the following standards:
(1) final grade shall not penetrate a plane that begins 30 inches above curb level at each lot line and has a slope extending perpendicular to lot lines of one foot vertical for each 2.5 feet horizontal;
(2) retaining walls shall be permitted above curb level in yards provided the maximum height of each wall above adjacent grade does not exceed 30 inches; and
(3) in front yards in Residence Districts, portions of fences greater than four feet above curb level shall be required to be no more than 50 percent opaque; and
(b) in C7 and C8 Districts and in Manufacturing Districts, yards shall be permitted to a maximum grade equal to flood-resistant construction elevation. However, for portions of zoning lots where Sections 33-29 and 43-30 (SPECIAL PROVISIONS APPLYING ALONG DISTRICT BOUNDARIES) apply, yards are permitted above curb level only pursuant to paragraph (a) of this Section.
Nothing in this Section shall be construed so as to permit the creation of spaces sub-grade on all sides in a manner inconsistent with Appendix G of the Building Code.