(a) Any sidewalk heretofore laid shall not be raised or lowered without the approval of the Commissioner of Engineering and Construction. All sidewalks hereafter laid shall be in accordance with the provisions of this chapter and under the supervision of the Commissioner.
(b) No curb line or grade for curb shall be changed, except by the direction and the written consent of the Director of Public Service or Commissioner.
(c) Any sidewalk laid on any public street or highway within the City in a manner inconsistent with the provisions of this chapter shall, upon the recommendation of the Director, be ordered relaid to the proper grade, upon the failure of the property owner to make the change so ordered within the time specified in the notice.