For all developments or enlargements on the lowest story of a building on primary transit-adjacent sites, a determination by the transit agency as to whether a transit volume is needed on the zoning lot shall be obtained pursuant to the provisions of this Section prior to any application with the Department of Buildings for an excavation permit, foundation permit, new building permit or alteration permit. An initial determination by the transit agency shall be made in accordance with paragraph (a) of this Section. Where a transit volume is needed based on the initial determination, the dimensions and location of such transit volume shall be established in accordance with paragraph (b) of this Section, and certified by the Chairperson of the City Planning Commission pursuant to paragraph (c).

1. Initial determination
   
   The owner of the zoning lot shall request a determination by the transit agency as to whether or not a transit volume is needed on the portion of the zoning lot not otherwise occupied by existing buildings that will remain. Within 30 days of receipt of such request, the transit agency shall issue a determination, indicating whether or not a transit volume is needed on such portion of the zoning lot. Failure by the transit agency to issue the determination within the 30-day period will release the owner from any obligation to provide a transit volume on such zoning lot.
   
   Where the transit agency determines a transit volume is needed on the zoning lot, the provisions of paragraphs (b) and (c) of this Section shall apply. Where the transit agency determines a transit volume is not needed, a building permit may be issued for such development or enlargement, and no remaining provisions of this Section shall apply.
2. Determination of easement dimensions and location
   
   Where a transit volume is needed, as determined pursuant to the provisions of paragraph (a) of this Section, the transit agency shall, within 30 days, determine the appropriate type, dimensions and general location of the transit volume on the zoning lot based on a concept plan for the use of such volume. Prior to the 30-day period, the transit agency may request relevant materials from the owner of the zoning lot, including existing and proposed site conditions, or other necessary information that will support the planning of such transit volume.
   
   After the size and general location of the transit volume has been determined by the transit agency, the owner shall submit for approval by the transit agency a site plan showing a proposed specific location of the transit volume that would be compatible with the proposed development or enlargement on the zoning lot. The transit agency shall, within 30 days of its receipt, either approve the site plan, or request modifications to the transit volume within the site plan in a manner that aligns with the concept plan. Upon such request, the owner shall submit a revised site plan, and within 15 days of its receipt, the transit agency shall confirm that the requested modifications have been addressed. In the event that such requested modifications have not been sufficiently addressed, subsequent revisions to the site plan may be requested by the transit agency, and each submission shall have a 15-day review period from the transit agency.
   
   Upon approval of the site plan by the transit agency, such site plan shall be certified by the Chairperson of the City Planning Commission pursuant to paragraph (c) of this Section prior to the issuance of a building permit by the Department of Buildings for such development or enlargement. Notwithstanding the above, a building permit may be issued for a development or enlargement:
   1. where the size of the proposed transit volume exceeds 25 percent of the width of any street frontage on the zoning lot, as measured along the street line; or
   2. where the number of days associated with the determination and review periods by the transit agency exceeds any of the limits set forth in this paragraph, or a total review period of 120 days. The total review period shall only be inclusive of the duration of the transit agency’s determination and review periods set forth in both paragraphs (a) and (b) of this Section.
3. Chairperson certification
   
   Upon approval of the site plan by the transit agency, a legally enforceable instrument, running with the land and setting forth the dimensions and location of a transit volume, shall be executed and recorded in a form acceptable to the transit agency and Chairperson of the City Planning Commission. The Chairperson shall be provided with a certified copy of the legally enforceable instrument, and upon receipt, shall certify the application and forward copies of such certification to the Commissioner of the Department of Buildings. Such certification shall be a precondition for the utilization of the remaining provisions of Section 66-20, inclusive, in any development or enlargement on a zoning lot where a transit volume is needed.
   
   Where an easement volume is needed on the zoning lot pursuant to paragraph (a) and (b) of this Section, additional requirements setting forth the construction, maintenance and other obligations shall apply pursuant to the provisions of Section 66-41 (Construction, Maintenance and Other Obligations).
   
   No temporary or final certificate of occupancy for the development or enlargement shall be granted until the Chairperson of the City Planning Commission notifies the Department of Buildings that the execution and recordation of other basic terms of the easement volume setting forth the obligations and requirements of either the transit agency or the owner and developer, their successors and assigns, inclusive of the requirements set forth in Section 66-41, have been completed.