Such conversion, alterations or improvements shall be completed within thirty months after the date on which same shall be started except that such thirty month limitation shall not apply to conversions of residential units which are registered with the loft board in accordance with article seven-C of the multiple dwelling law pursuant to subparagraph one of this paragraph. Notwithstanding the foregoing, a sixty month period for completion shall be available for alterations or improvements undertaken by a housing development fund company organized pursuant to article eleven of the private housing finance law, which are carried out with the substantial assistance of grants, loans or subsidies from any federal, state or local governmental agency or instrumentality or which are carried out in a property transferred from such city if alterations and improvements are completed within seven years after the date of transfer. In addition, the local housing agency is hereby empowered to grant an extension of the period of completion for any project carried out with the substantial assistance of grants, loans or subsidies from any federal, state or local governmental agency or instrumentality, if such alterations or improvements are completed within sixty months from commencement of construction. Provided, further, that such conversion, alterations or improvements shall in any event be completed prior to June thirtieth, two thousand twenty-two. Exemption for conversions, alterations or improvements pursuant to subparagraph one, two, three or four of this paragraph shall continue for a period not to exceed fourteen years and begin no sooner than the first quarterly tax bill immediately following the completion of such conversion, alterations or improvements. Exemption for alterations or improvements pursuant to this subparagraph or subparagraph five of this paragraph shall continue for a period not to exceed thirty-four years and shall begin no sooner than the first quarterly tax bill immediately following the completion of such alterations or improvements. Such exemption shall be equal to the increase in the valuation which is subject to exemption in full or proportionally under this subdivision for ten or thirty years, whichever is applicable. After such period of time, the amount of such exempted assessed valuation of such improvements shall be reduced by twenty percent in each succeeding year until the assessed value of the improvements are fully taxable. Provided, however, exemption for any conversion, alterations or improvements which are aided by a loan or grant under article eight, eight-A, eleven, twelve, fifteen or twenty-two of the private housing finance law, section six hundred ninety-six-a or section ninety-nine-h of the general municipal law, or section three hundred twelve of the housing act of nineteen hundred sixty-four (42 U.S.C.A. 1452b), or the Cranston-Gonzalez national affordable housing act (42 U.S.C.A. 12701 et. seq.), or started after July first, nineteen hundred eighty-three by a housing development fund company organized pursuant to article eleven of the private housing finance law which are carried out with the substantial assistance of grants, loans or subsidies from any federal, state or local governmental agency or instrumentality or which are carried out in a property transferred from any city and where alterations and improvements are completed within seven years after the date of transfer may commence at the beginning of any tax quarter subsequent to the start of such conversion, alterations or improvements and prior to the completion of such conversion, alterations or improvements.
4-a-1. Notwithstanding any contrary provision of subdivision four of this section, any such local law or ordinance shall provide that the availability of benefits under this section to any multiple dwelling, building or structure owned and operated by a redevelopment company established pursuant to article five of the private housing finance law shall not be conditioned upon the assessed valuation of such multiple dwelling, building or structure, including land, as calculated as an average dollar amount per dwelling unit, at the time of the commencement of the alterations or improvements: provided, however, that such redevelopment company (a) is organized and operating as a mutual redevelopment company, (b) continues to be organized and operating as a mutual redevelopment company and to own and operate the multiple dwelling, building or structure receiving such benefits, and (c) has entered into a binding and irrevocable agreement with the commissioner of housing and community renewal, the supervising agency, the New York city housing development corporation, or the New York state housing finance agency prohibiting the dissolution or reconstitution of such redevelopment company pursuant to section one hundred twenty-three of the private housing finance law until the earlier to occur of: (i) in fifteen years from the commencement of such benefits, or (ii) the expiration of any tax exemption granted to such redevelopment company pursuant to section one hundred twenty-five of the private housing finance law. For the purposes of this subdivision, the terms "mutual" and "supervising agency" shall have the same meanings as set forth in section one hundred two of the private housing finance law.
Property with a total assessed valuation per dwelling unit of thirty-eight thousand dollars or more shall not be eligible for a tax exemption under this section.
York mortgage agency of the New York city residential mortgage insurance corporation; or
N.Y. Real Prop. Tax. Law § 489