Section 84 of chapter 179 of the acts of 2020 is hereby amended by striking out subsection (c) and inserting in place thereof the following new subsection:-

(c) Upon application, the department shall accept into the demonstration program established pursuant to this section any city or town that has received local approval; provided, that the department shall, in the interest of increasing housing production in the commonwealth, withhold approval of an application by a city or town applying to participate in the demonstration project until such time as said city or town has: (i) met the 10 per cent housing affordability threshold set under chapter 40B of the General Laws or has been granted safe harbor status through an approved Housing Production Plan by the department of housing and community development; or (ii) has approved a zoning ordinance or by-law that provides for at least 1 district of reasonable size in which multi-family housing is permitted as of right; provided, that such multi-family housing shall be without age restrictions and shall be suitable for families with children; provided further, that a city or town that met the 10 per cent affordability threshold as of December 21, 2020, shall be deemed to have satisfied the requirements of this paragraph. For the purposes of this section, multi-family housing shall be a building with 3 or more residential dwelling units or 2 or more buildings on the same lot with more than 1 residential dwelling unit in each building and a district of reasonable size shall have a minimum gross density of 15 units per acre, subject to any further limitations imposed by section 40 of chapter 131 of the General Laws and title 5 of the state environmental code established pursuant to section 13 of chapter 21A of the General Laws.