(a) subject to paragraph (b) -
(i) means a building or part of a building fixed on land that is used, or is set aside to be used, primarily for the purpose of any industry, trade or other business undertaking, and
(ii) includes -
(I) the land on which such building or such part of a building, as the case may be, is located, and
(II) the fixtures that are used in conjunction with such building or such part of a building, as the case may be,
(b) does not include either -
(i) a building or part of a building that is fixed on land that is used, or is set aside to be used, primarily for the purpose of any mine, quarry or agriculture, or
(ii) subject to section 4(6) and (7), a building or part of a building that is residential property