Existing single-family dwellings on legal nonconforming lots of record, which are substandard as to minimum building site area, lot width, and/or density requirements, may be replaced with new single-family dwellings, provided all other development standards set forth in this title, such as building height, setbacks, lot coverage, and other similar standards, are met and the new structure conforms to all current city codes. No use permit shall be required for such replacement, unless a use permit would otherwise be required for construction of a single-family dwelling in the district in which it is located.