Unless the context otherwise indicates, the following definitions shall be used in the interpretation and construction of this chapter. Words used in the present tense include the future; the singular number shall include the plural and the plural, the singular; the word "structure" shall include the word "building": the word "person" shall include a corporation as well as an individual; the word "lot" shall include the word "plot"; the word "occupies" shall include the words "designed or intended to be occupied"; the word "used" shall include the words "arranged, designed, constructed, altered, converted, rented, leased or intended to be used"; the word "shall" is mandatory and not optional, and the word "may" is permissive.