SECTION 1. Section 20 of chapter 40B, as appearing in the 2006 Official Edition, is hereby amended by striking the definition of “consistent with local needs” and inserting in place thereof the following:--

             "Consistent with local needs'', requirements and regulations shall be considered consistent with local needs if they are reasonable in view of the regional need for low and moderate income housing considered with the number of low income persons in the city or town affected and the need to protect the health or safety of the occupants of the proposed housing or of the residents of the city or town, to promote better site and building design in relation to the surroundings, to preserve the municipal water supply or the region’s natural water resources, or to preserve open spaces, and if such requirements and regulations are applied as equally as possible to both subsidized and unsubsidized housing. Requirements or regulations shall be consistent with local needs when imposed by a board of zoning appeals after a comprehensive hearing in a city or town where (1) low or moderate income housing exists which is in excess of ten percent of the housing units reported in the latest federal decennial census of the city or town or on sites comprising one and one half percent or more of the total land area zoned for residential, commercial or industrial use or (2) the application before the board would result in the commencement of construction of such housing on sites comprising more than three tenths of one percent of such land area or ten acres, whichever is larger, in any one calendar year; provided, however, that land area owned by the United States, the commonwealth or any political subdivision thereof, or any public authority shall be excluded from the total land area referred to above when making such determination of consistency with local needs.