If the written consent and a waiver of claims for damages against the City or the owners of property abutting upon the side of any proposed building or construction is first obtained and filed with the director of public works, the permission to occupy a street, alley, and sidewalk space may be extended beyond limitations of such building in front of the property for which the consent of the owner or lessee thereof has been secured upon the same terms and conditions as those fixed for the occupancy of sidewalk, street, and alley abutting upon a building site.