The time allotted to complete the work for which a permit was issued or recommendation
made under this division shall be limited to the time stipulated on the permit, unless
the permittee requests the county engineering department to grant an extension of
time prior to the expiration thereof. In the event the permittee, as owner-contractor
or agent, is constructing or enlarging a structure on lands abutting or adjoining
the public property affected by a permit granted hereunder, the permit granted hereunder
shall be posted and displayed on such land in the same manner as building permits
are now required to be posted and displayed. No final inspection of such construction
shall be made by the building department, nor shall a certificate of occupancy be
issued, without the endorsement of the approval of the engineering inspector upon
such posted permit required hereunder.