No commercial signs shall be permitted upon private properties
not otherwise authorized to display the same as part of a zoning approved
use, unless to identify a contractor actively engaged in performing
construction work at the property. Such signs shall be no more than
three square feet in area and shall be removed within 30 days of the
completion of work at the property. In any event, no such signs shall
be left upon any property for longer than 90 days, except in the case
of new construction, in which event the sign shall be removed no later
than 30 days after issuance of a certificate of occupancy.
The penalties for violation of this chapter shall be as prescribed in Chapter
103 of this Code.