18.20.100: DENSITY OF DEVELOPMENT:
In the A-1 district, population density shall be one dwelling unit per two and one-half (21/2) acres. For lots existing at the time of the adoption hereof, not more than one dwelling unit shall be located on any lot containing less than two and one-half (21/2) acres. (Ord. 1000 § 12.20(C), 1955)