The following provisions shall apply to all
buildings, structures and uses lawfully existing on the effective
date of this article, to all buildings and uses that may become nonconforming
or noncomplying by reason of any subsequent amendment to this article
and the Zoning Map and to all complying buildings housing nonconforming
uses.
Nothing herein contained shall require any change
in plans, construction or designated use of a building for which lawful
construction has commenced prior to the effective date of this chapter.