In the case of a protest against such change
signed by the owners of 20% or more either of the area of the lots
or lands included in such proposed change or of the lots or the land
in the rear thereof extending 100 feet therefrom, or of the lots or
land on either side thereof or directly opposite thereto extending
100 feet therefrom (exclusive of street space), such change shall
not become effective except by the favorable vote of 2/3 of the
members of the governing body.