No display sign except tourists signs, church signs, institutional signs, real estate signs and home sale signs as permitted by City Ordinance shall be erected after the effective date of this chapter in any R- District, except as otherwise provided for in the chapters of this Zoning Code governing uses permitted in the several it-Districts, and except also that in the R-3 district, business signs attached to lawful business buildings may be authorized by the Zoning Inspector upon a finding that the same are reasonably required in connection with their proposed use and at the same time will comply with the provisions of this chapter. Such attached business signs shall be no more than two square feet in area. In addition, free standing signs may be permitted in the front yards of lawful business buildings in an R-3 area with the approval of the Zoning Inspector. Such free standing signs shall be no larger than three square feet in total area including both sides of the sign. Such authorization as may be granted hereunder is, however, subject to such conditions and restrictions as the Zoning Inspector may deem necessary for the protection of other property in or adjacent to such R-3 District. Each lawful business building in such R-3 District shall be limited to one business sign, either as attached to the building or as a free standing sign, in conformity with the provisions of this chapter for such signs.