An improvement to any real property used solely
for residential purposes as a one-, two- or three-family residence
shall be exempt from taxation to the extent of any increase in value
attributable to such improvement if such improvement is used for the
purpose of facilitating and accommodating the use and accessibility
of such real property by a resident owner of the real property who
is physically disabled or a member of the resident owner's household
who is physically disabled, if such member resides in the real property.
The procedure for applying for the granting
of said exemption shall be in accord within the provisions of § 459
of the Real Property Tax Law and shall apply to an improvement constructed
and added to the tax rolls after January 1, 1981.