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 an extension,
modification or addition; 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 an open deck that does
not exceed 200 square feet in area 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.