A garrison is style of house

House

A house is a building or structure that has the ability to be occupied for dwelling by human beings or other creatures. The term house includes many kinds of different dwellings ranging from rudimentary huts of nomadic tribes to free standing individual structures...

, typically two stories

Storey

A storey or story is any level part of a building that could be used by people...

 with the second-story overhanging in the front. The traditional ornamentation is four carved drops (pineapple or acorn shape) below the overhang. Garrisons usually have an exterior chimney at the end. Older versions have casement window

Casement window

A casement window is a window that is attached to its frame by one or more hinges. Casement windows are hinged at the side. A casement window (or casement) is a window that is attached to its frame by one or more hinges. Casement windows are hinged at the side. A casement window (or casement) is a...

s with small panes of glass, while later versions have double-hung windows. The second-story windows often are smaller than those on the first floor. Dormer

Dormer

A dormer is a structural element of a building that protrudes from the plane of a sloping roof surface. Dormers are used, either in original construction or as later additions, to create usable space in the roof of a building by adding headroom and usually also by enabling addition of windows.Often...

s often break through the cornice line

Cornice

Cornice molding is generally any horizontal decorative molding that crowns any building or furniture element: the cornice over a door or window, for instance, or the cornice around the edge of a pedestal. A simple cornice may be formed just with a crown molding.The function of the projecting...

.