The same provisions shall apply as for extensions into required front and rear yards, except that no porch, terrace or outside stairway shall project more than four feet into any required side setback and an outside stairway may extend into any required side yard only if same is unroofed and unenclosed above and below the steps thereof.

Fire escapes, which are not stairways, shall end at least eight feet above the ground with a device for lowering in case of emergency.