A horizontal enlargement of the ground floor and second floor levels within an arcade located within Area A on Map 9 in Appendix A of this Chapter may be permitted upon certification by the Chairperson of the City Planning Commission to the Commissioner of Buildings that such enlargement complies with the provisions of this Section, and the following conditions are met:

(a)        the horizontal enlargement meets the requirements of Section 91-831 (Ground floor requirements);

(b)        a compensating amenity is provided pursuant to the provisions of Section 91-832 for plaza improvements, Section 91-834 for indoor public spaces, or Section 91-835 for alternative improvements; and

(c)        the additional requirements of Section 91-836, as applicable.

For zoning lots with one or more publicly accessible open area, unless an alternative improvement has been identified in Section 91-835, an improvement to all publicly accessible open areas pursuant to the provisions of Section 91-832 shall be required as the compensating amenity required by condition (b) of this Section, and a certification for design changes pursuant to Section 37-625 shall not be required. Where a publicly accessible open area was improved and is fully compliant with a prior certification pursuant to Section 37-625 that was granted before January 19, 2016, the further improvement of such publicly accessible open area shall not be required.

The provision of a compensating amenity as part of a prior certification pursuant to this Section or a prior authorization pursuant to Section 91-841 (Authorization for retail uses within existing arcades) may satisfy the requirements of condition (b) of this Section for a compensating amenity.

As part of the certification, a horizontal enlargement of the ground floor level may be permitted within the area between a street wall and an arcade that did not generate a floor area bonus prior to June 21, 2016. The provisions of Section 91-831 (Ground floor requirements) shall not apply to such portion of the horizontal enlargement.

As part of the certification, a horizontal enlargement of the ground floor level may be permitted along existing building walls that do not face an arcade, and such enlargement shall not occupy any publicly accessible open area. The locational requirements of paragraph (a)(1) of Section 91-831 and the frontage prohibitions of paragraph (b)(1)(ii) of Section 91-831 shall apply to such enlargement. Where an enlargement is located adjacent to a publicly accessible open area, the use and transparency requirements of Section 91-831 for new building walls facing a publicly accessible open area shall apply.

For a horizontal enlargement of 7,500 square feet or greater, a special permit pursuant to Section 91-85 shall also be required. For the purposes of calculating the total area of the horizontal enlargement that is subject to the special permit, the aggregate area of the horizontal enlargement permitted by prior certifications pursuant to this Section and Section 91-837 (Subsequent design changes) and prior authorizations pursuant to Section 91-841 shall be included in such calculation, except the area of an indoor public space shall be excluded from such calculation.

Where any portion of the arcade remains open and accessible, such remaining arcade area shall maintain a minimum level of illumination of not less than five horizontal foot candles between sunset and sunrise. Any non-transparent portion of a building wall between columns that fronts on such arcade area shall be treated with artwork, planting or decorative material. Additional requirements for transparency in paragraph (c)(3) of Section 91-831 may apply.