It shall be unlawful to alter or in any way modify plans that have been stamped as approved by the director of public works, as provided by this article. If, during the progress of such work, it is desired to deviate, in any manner affecting the construction or other essentials of the building, from the terms of the application, or drawing, notice of such intention to alter or deviate shall be given to the director of public works, and his or her written assent shall first be obtained before such alteration or deviation may be made; but alterations in buildings which do not involve any change in their structural parts or of their stairways, elevators, fire escapes or other means of communication or ingress or egress, or in lighting or ventilation or in plumbing or electric wiring, and that are not in violation of any of the provisions of this chapter, may be made without the permission of the director of public works.