SECTION 1. Section 6 of chapter 40A of the General Laws, as appearing in the 2016 Official Edition, is hereby amended by striking out the fourth paragraph and inserting in place thereof the following 2 paragraphs:-

Any increase in area, frontage, width, yard, or depth requirements of a zoning ordinance or by-law shall not apply to a lot for single and 2 family residential use which at the time of recording or endorsement, whichever occurs sooner, conformed to then existing requirements and had less than the proposed requirement but at least 5,000 square feet of area and 50 feet of frontage. Any lot that was recorded and held in common ownership with any adjoining land and conformed to the existing zoning requirements when recorded shall continue to be a buildable lot, and shall be exempt from merger. Adjacent lots in common ownership shall continue to be separate and buildable lots. Any increase in area, frontage, width, yard or depth requirement of a zoning ordinance or by-law shall not apply to any lot recorded prior to said increase; provided,  that the lot has at least of 15,000 square feet of area and 75 feet of frontage. Adjacent lots in common ownership shall be treated as separate lots for the purposes of this chapter. This chapter shall permit adjacent lots in common ownership to be built upon and current zoning by-laws in effect in a city or town shall be amended to allow building upon such lots.

No zoning ordinance  prohibit the construction of a single family home of not more than 1,600 square feet and 2 bedrooms for individuals age 55 or older on a lot of not less than 15,000 square feet. No zoning ordinance shall require cluster construction for the construction of homes for individuals age 55 or older.

SECTION 2. Section 21 of chapter 40B of the General Laws, as so appearing, is hereby amended by inserting after the word “housing”, in line 2, the following words:-

or single family housing for individuals age 55 and older on a lot of not less 15,000 square feet.

SECTION 3. Section 5 of chapter 59 of the General Laws, as so appearing, is hereby amended by striking out clauses Forty-first, Forty-first A, Forty-first B, Forty-first C, Forty-first C½, Forty-first D and inserting in place thereof the following clause:-

Forty-first,  Real property, to the amount equal to 50 per cent of the amount of taxes due, of a person who has reached their fifty-fifth birthday prior to the fiscal year for which an exemption is sought and occupied by said person as their domicile, or of a person who owns the same jointly with their spouse, either of whom has reached their fifty-fifth birthday prior to the fiscal year for which an exemption is sought and occupied by them as their domicile, or for a person who has reached their fifty-fifth birthday prior to the fiscal year for which an exemption is sought who owns the same jointly or as a tenant in common with a person not their spouse and occupied by the person as their domicile.