For the purposes of applying the street wall regulations of this Section, developments shall include alterations and enlargements that change the height, width or location of a street wall.

All portions of buildings or other structures located above the maximum base heights specified in paragraph (a) of this Section shall provide a setback in accordance with the regulations of Section 91-32 (Setback Regulations).

(a)        Within the Special District, the maximum base height shall be 85 feet or 1.5 times the width of the street upon which the building fronts, whichever is greater, except as provided for the following types of street wall regulations:

(1)        Street wall regulations: Type 1

For developments that front upon a street indicated as "Type 1" on Map 2 (Street Wall Continuity Types 1, 2A, 2B and 3) in Appendix A, street walls shall extend along the entire street frontage of the zoning lot not occupied by existing buildings to remain, to a minimum base height of 150 feet or the height of the building, whichever is less. The maximum base height shall be 250 feet.

(2)        Street wall regulations: Type 2A

For developments that front upon a street indicated as "Type 2A" on Map 2 in Appendix A, street walls shall extend along such entire street frontage of the zoning lot not occupied by existing buildings to remain, to a minimum base height of 85 feet or the height of the building, whichever is less. The maximum base height shall be 150 feet.

(3)        Street wall regulations: Type 2B

For developments that front upon a street indicated as "Type 2B" on Map 2 in Appendix A, street walls shall extend along at least 60 percent of such street frontage of the zoning lot not occupied by existing buildings to remain, to a minimum base height of 85 feet or the height of the building, whichever is less. The maximum base height shall be 150 feet.

(4)        Street wall regulations: Type 3

For developments that front upon a street indicated as "Type 3" on Map 2 in Appendix A, street walls shall extend along the entire street frontage of the zoning lot not occupied by existing buildings to remain, to a minimum base height of 60 feet, five stories, or the height of the building, whichever is less. The maximum base height shall be 85 feet or 1.5 times the width of the street upon which the building fronts, whichever is greater.

(5)        Street wall regulations: Type 4

For developments that front upon a street within the Historic and Commercial Core, indicated as "Type 4" on Map 3 (Street Wall Continuity Types 4 and 5) in Appendix A, the maximum base height shall be 100 feet.

(6)        Street wall regulations: Type 5

For developments that front upon a street indicated as "Type 5" on Map 3 in Appendix A, no setbacks are required for any portion of a building.

(b)        For developments that front upon a street indicated as "Type 1" or "Type 2A," at least 70 percent of the aggregate width of street walls shall be located on such street line. For developments that front upon a street indicated as “Type 2B,” at least 60 percent of the aggregate width of street walls shall be located within 10 feet of such street line. For developments that front upon a street indicated as "Type 3," at least 70 percent of the aggregate width of street walls shall be located within 10 feet of such street line. The remaining 30 percent of the aggregate width of street walls may be located beyond such street lines in compliance with:

(1)        the outer court regulations of Article II, Chapter 3, for residential portions of buildings;

(2)        the outer court regulations of Article II, Chapter 4, for all other portions of buildings; or

(3)        the requirements of Section 37-50 where such areas are pedestrian circulation spaces.

(c)        When a building fronts on two intersecting streets for which different maximum base heights are specified, the higher maximum base height may wrap around to the street with the lower maximum base height for a distance along the street line of 100 feet. However, "Type 5" street walls shall not be permitted to wrap around to the intersecting street.

(d)        Arcades and sidewalk widenings that meet the design standards of Section 37-53 (Design Standards for Pedestrian Circulation Spaces) shall be permitted along any street indicated as "Type 1," "Type 2A" or "Type 3," pursuant to paragraphs (a), (b) or (c) of this Section, provided such arcade or sidewalk widening extends along the entire block frontage or abuts another arcade, existing on August 27, 1998, of equal width and height or another sidewalk widening of equal width. In such case, the street wall requirements for paragraph (b) of this Section shall be measured from the permitted arcade or sidewalk widening.