Within the R-40 and R-20 Residential Zones, no premises, building or structure shall be used and no building or structure shall be erected or altered to be used in whole or in part for any other than the following purposes:
A.
Single-family dwelling used as a residence by not more than one family.
B.
Extended family dwelling. An extended family dwelling unit within an extended family dwelling shall have separate cooking, sleeping, and sanitary facilities from the principal dwelling unit. However, an extended family dwelling unit shall be subject to the following restrictions:
(1)
An extended family dwelling unit shall not exceed 550 square feet and shall not exceed one bedroom.
(2)
An extended family dwelling unit shall share a common unseparated entranceway and exit way with the principal dwelling unit.
(3)
An extended family dwelling unit shall share common utility meters with the principal dwelling unit.
(4)
An extended family dwelling unit shall not be permitted in an two-family house.
(5)
Home occupations and professional offices shall not be permitted in an extended family dwelling.
(6)
A building permit for an extended family dwelling shall require evidence of a recordation of a restrictive covenant, running with the land, prohibiting occupancy by two families unrelated by blood or marriage in any extended family dwelling.
D.
Professional offices. The use of a portion of a dwelling as a professional office shall be permitted, provided that such use shall be restricted to the first floor of the building and shall not exceed 25% of the total floor area of the building.