(a) In any case of demolition, alteration, subdivision, or new construction in which a hearing was held, the Mayor’s decision on such application shall not become final until 15 days after issuance. In all applications for which a hearing is held, the Mayor’s decision must be issued within 120 days after the hearing record is closed, including the filing of any required post-hearing submissions. (b) All proceedings pursuant to this subchapter shall be conducted in accordance with the applicable provisions of Chapter 5 of Title 2.