The side yard regulations for dwellings are the same as in the "B" multiple dwelling district. In all other cases a side yard is not required except:
A. On the side of a lot adjoining a dwelling district in which case there shall be a side yard of not less than five feet; and
B. On the street side of a corner lot rearing upon a dwelling district in which case there shall be a side yard of not less than five feet (Prior code § 11-3-4 (d) (2))