In addition, if the Commissioner of the Department of Housing and Buildings determines that an application, with accompanying construction plans, for a building permit filed prior to the effective date of this chapter meets all requirements of the Zoning Ordinance in existence as of the date immediately prior to the effective date of this chapter, has received all necessary conditional or final approvals by the Planning Board or the Zoning Board of Appeals or other authorized approving agency, and complies with the use requirements of this chapter, then the Commissioner of the Department of Housing and Buildings shall issue all necessary permits within a reasonable time, but not longer than 60 days from such date, provided that the applicant has taken all steps deemed necessary by the Commissioner of the Department of Housing and Buildings to obtain such permit.