Lot Area and Width. A lot area of not less than 11,250 square feet per family shall be provided for every building hereafter erected or used in whole or in part as a dwelling, provided that where lots are recorded at the effective date of the Zoning Ordinance which are less than 150 feet in depth, the lot area per family required may be reduced to not less than 9,400 square feet. Each lot shall have width at the building line of not less than 75 feet, subject to the provisions of Subsection 35-24.1.