Buildings or uses which are customarily accessory to a use permitted in one district shall not be permitted in a district of a higher classification.

For any single-family dwelling, there shall be permitted one (1) detached private garage, provided that such garage shall be located not less than sixty (60) feet from the front lot line, not less than six (6) feet from any side lot line, nor less than one (1) foot from any alley line, except that when the rear lot line is common to a side or rear lot line of another lot, such outbuilding must be a minimum of three (3) feet from said rear lot line and in the case of corner lots not less than the distance required for dwellings from side streets.

In any district, a detached accessory building not exceeding twenty-four (24) feet or two (2) stories in height or, in any case, not higher than the main building, may occupy not more than thirty (30) percent of a rear yard. In District “R-2” through “M” inclusive, if such building is not more than one (1) story or sixteen (16) feet high, it may occupy forty (40) percent of the rear yard. No part of a detached accessory building may be connected with the main building [except] by a lightly constructed, covered passage, open on each side and not more than six (6) feet wide inside, the roof of which is not more than twelve (12) feet high at its highest point and is not an extension of the roof or main building.

A barn may be built in any district if placed on a tract of land three (3) acres or larger without having a main building provided the bar [barn] does not exceed two stories or twenty-four (24) feet in height.