Any lot or parcel of land under one ownership and of record on the day of incorporation of the city may be used as a building site, even when of less area or width than that required by the regulations for the zoning district in which it is located. Such lot or parcel shall be subject to the setbacks and all other regulations applying to standard-size lots in the zoning district where the lot or parcel is located, unless a variance or waiver has been approved. [Res. 21-09; Ord. 21-05 § 2; Res. 14-36 § 401.07; Ord. 14-12 § 1.]