The Building Inspector shall examine or cause to be examined every building or structure or portion thereof reported as dangerous or damaged and, if such is found to be an unsafe building, the Building Inspector shall give to the owner of such building or structure written notice stating the defects therein. This notice may require the owner or person in charge of the building or premises, within 48 hours, to commence either the required repairs or improvements or demolition and removal of the building or structure or portions thereof, and all such work shall be completed within 90 days from the date of notice, unless otherwise stipulated by the Building Inspector. If necessary, such notice also shall require the building, structure, or portion thereof to be vacated forthwith and not reoccupied until the required repairs and improvements are completed, inspected, and approved by the Building Inspector. Proper service of such notice shall be by personal service upon the owner of record, if he shall be found within the city. If he is not found therein such service may be made upon said owner by registered mail or certified mail, provided, that if such notice is by registered mail or certified mail, the designated period within which the owner or person in charge is required to comply with the order of the Building Inspector shall begin as of the date he receives such notice.
(1975 Code, § 4.09, Subd. 2)