A sign may be temporarily located on a site where construction is underway. There can be a maximum of three such signs per site. Each residential construction signs can be no more than 6 square feet in size, while a non-residential construction sign may be up to 12 square feet. These signs cannot be illuminated and are only permitted through the duration of construction and shall be removed no later than ten days following completion of construction. 

Link to the complete construction sign section of the Sign Ordinance.