A dwelling designed and built for a household shall be classed as a residence if the rooms have not been altered to provide for the functions of more than one household and separate households are not maintained. It is the intent of this rule that a dwelling is not to be classed as commercial if one or more rooms are rented to a person or person who may sleep, but not prepare meals in the rooms. [Ord. 962 Art. II, § 15, 1959; Code 1970 § 13.04.050; Code 1954 § 4-3.28.]