No modifications or additions to a nonconforming use or structure
shall be permitted unless they comply with this chapter. The words
"modification" and "addition" include, but are not limited to, any
alteration, addition, modification, structural repair, rebuilding
or replacement of any such existing use, structure or accessory structure
or use. Ordinary maintenance repairs are not considered modifications
or additions; these include painting, decorating, paneling and the
replacement of doors, windows and other nonstructural components and
the maintenance, repair or replacement of existing private sewage
or water supply systems or connections to public utilities. Ordinary
maintenance repairs do not include any costs associated with the repair
of a damaged structure. The construction of a deck that does not exceed
200 square feet and that is adjacent to the exterior wall of a principal
structure is not an extension, modification or addition. The roof
of the structure may extend over a portion of the deck in order to
provide safe ingress and egress to the principal structure;