There shall be no more than one (1) single family or two (2) family residential principal building erected on any lot.
b.
All principal buildings and required front yard areas must face on a dedicated public street, or on a private street or access driveway approved by the Planning Board.
c.
Exterior alterations which substantially change the character and nature of a building for the purpose of changing the use of the building from residential use shall not be permitted in any residential district.