FWIW:
An old standard carriage house width in the 1920's & 1930's was 12'-0" out-to-out for a horse drawn carriage which was later used for a single vintage car garage.
Four inches were allowed on each side for exterior studs, about 5'-8" to maneuver the carriage or car & 2'-6" maneuver space on both sides which was also used to hang buggy harness.
By today's standard, this 12 feet would be considered tight because of no shelf space on either side; plus, male & female waist measurements back then were often times under 36" which meant the car door did not have to open very wide. LOL