Notwithstanding the provisions of Subsection A above, as provided in MGL c. 40A, § 6, if any proposed extension, alteration, reconstruction, or structural change to a single- or two-family residential structure complies with one of the conditions set forth in Subsection B(1) through (5) below, such extension, alteration, reconstruction or structural change shall not be considered an increase in the nonconforming nature of the structure and shall be permitted as of right.
(1)
Extension, alteration, reconstruction or structural change to a structure which complies with all current setbacks, lot coverage and building height requirements but is located on a lot with insufficient area where the alteration will also comply with all of said current requirements.
(2)
Extension, alteration, reconstruction or structural change to a structure which complies with all current setbacks, lot coverage and building height requirements but is located on a lot with insufficient frontage where the alteration will also comply with all of said current requirements.
(3)
Extension, alteration, reconstruction or structural change to a structure which encroaches upon one or more required setbacks where the alteration will comply with all current setbacks, open lot coverage and building height requirements. The provisions of this subsection shall apply regardless of whether the lot complies with current area and frontage requirements.
(4)
Extension, alteration, reconstruction or structural change to the rear, side or fascia of a structure which encroaches upon a required yard or setback area where the alteration will not encroach upon such area to a distance greater than the existing structure. The provisions of this subsection shall apply regardless of whether the lot complies with current area and frontage requirements.
(5)
Extension, alteration, reconstruction or structural change to a nonconforming structure which will not increase the footprint of the existing structure providing that existing height restrictions shall not be exceeded.