Recesses are permitted for architectural, decorative or functional purposes, provided that such recesses comply with the provisions of this Section.

For portions of the lower street wall required pursuant to the provisions of Section 104-33, the maximum area of recesses shall not exceed 30 percent of the area of such required lower street wall and the maximum depth of such recesses shall not exceed three feet.

For that portion of the upper street wall required pursuant to the provisions of Section 104-33, and located below a height of 85 feet on a wide street and 60 feet on a narrow street, the maximum area of recesses shall not exceed 30 percent of the area of such portion of the upper street wall and the maximum depth of such recesses shall not exceed three feet. However, the regulation limiting the maximum depth of such recesses to three feet, set forth in this paragraph, shall not apply to the recesses required in paragraph (d) of Section 104-331.