Following the effective date of this chapter,
no building or land shall be used or occupied and no building or part
thereof shall be erected, moved or altered unless in conformity with
the regulations specified for the zoning district in which it is located
or applicable special regulations.
Notwithstanding the limitations imposed by any
other provisions of the chapter, the Zoning Hearing Board may permit
erection of a dwelling on any lot (in a district where permitted by
this chapter) separately owned, or under contract of sale, and containing
at the time of the passage of this chapter an area or width smaller
than that required for a single-family dwelling.