Carriage House
They once held horse-drawn carriages, but carriage houses today hold mainly people
Carriage houses, also called coach houses, are detached structures that were once used to house horse-drawn carriages or coaches. Today carriage houses are often garages with secondary, smaller apartments built (typically) above the space for cars. In some cases the whole structure is transformed into a separate residential unit, eliminating vehicle storage.
Most carriage houses were built at the same time as the main houses and are like pared-down versions of them.
Carriage houses in the late 19th and early 20th centuries, such as at the Martin House, designed by Frank Lloyd Wright, literally stored carriages and had stables for horses.
Carriage houses tend to be behind a house, near the rear of its lot. But their location depends on the layout on the driveway.
Given the physical remove of carriage houses from the main houses, some of them, like this newly built one in British Columbia, are accessible directly from alleys.
In some contexts, such as Toronto, where the Millworker House is located, carriage houses are called laneway houses, referring to their locations on lanes or alleys.