§ 13-5. Nonconforming structures and trees.

The limitation prescribed in this chapter shall not be construed to require the removal, lowering or other change or alteration of any structure or tree not conforming to these regulations as of the effective date thereof or otherwise interfere with the continuance of any such nonconforming use. Nothing herein contained shall be construed to permit any such nonconforming structure or tree to be substantially altered or repaired, rebuilt, allowed to grow or replanted so as to become a greater hazard to air navigation than it was on the effective date of this chapter.