Whenever the mayor and city council shall order any sidewalk constructed, as provided in section 12.04.020 of this chapter, it shall be the duty of the city engineer within five (5) days after the passage of such order, to serve a written or printed notice to construct such sidewalks within thirty (30) days upon the owner or his agent of all of the property in front of which such sidewalk has been ordered laid. If the owner resides out of the city and his address is known, such notice shall be sent by registered mail, and if he cannot be found, and his address is unknown, such notice shall be published at least once a week for two (2) consecutive weeks in a newspaper published in the city. (Prior code §24-18)