The conversion of any building into a dwelling or the conversion of any dwelling so as to accommodate an increased number of dwelling units or families, shall be permitted only within a district in which a new building for similar occupancy would be permitted under this title, and only when the resulting occupancy will comply with other requirements governing new construction in such district with respect to minimum lot size, lot area per dwelling unit, percentage of lot coverage, dimensions of yards and other open spaces, and off-street parking. The aforesaid requirements with respect to lot coverage, yards and other open spaces, shall not apply if:
(A) No major exterior structural changes are made,
(B) Any shortage as to coverage, yards and open spaces will not be more than 10% of the required dimensions or areas, and
(C) The conversion will result in a lot area per dwelling unit not more than 20% less than the requirement for new buildings in the district.
('69 Code, § 7-15.06) Penalty, see § 155.999