Unless the context otherwise indicates, the following definitions shall be used in the interpretation and construction of the chapter. Words used in the present tense include the future; the singular number shall include the plural, and the plural the singular; the word "building" shall include the word "structure;" the word "person" includes a corporation as well as an individual; the word "lot" includes the word "plot," the word "occupied" includes 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.