A gambrel garage is a popular building design that references the shape of the garage's roof. Traditional A-frame roof designs, often referred to as gable roofs, feature two side panes peaked at the center to form an “A” shape, hence the term “A-framed.” Alternatively, gambrel roofs feature four side panes for a hexed profile and added space under the roof. Viewing a gambrel roof from the long side, instead of a continuous solid pane, the roof panes “break” horizontally along the middle and drop at a steeper angle, similar to a piece of paper creased along the center. Looking from either short side of the building, the hex-like shape of a gambrel garage roof is most noticeable.
The uppermost panes of a gambrel roof are typically situated at a wider angle than traditional gable two-pane roofs. Lower panes are situated at a steeper and therefore longer slope to provide a wider opening underneath. From a distance, the roof line on a gambrel garage can almost appear rounded. Several gambrel garage designs also feature an elongated eave at the peak of the roof, commonly known as a Dutch kick. While the origins of a Dutch kick trace back to barns that needed an extra overhang to protect hay doors, modern gambrel garages feature similar eaves for aesthetic appeal.
Historically, the design was adapted from English and Dutch structures common in rural agricultural areas. In farm communities along the Atlantic coast of the United States, the roof design enjoyed immense popularity during the 17th century. Many homes, barns, and carriage houses featured a gambrel roof, which added substantial living and storage space compared to a minimal increase in building cost.
Owing to the increased headroom and storage space in the attic area of the building, such garages, sheds, and barns have enjoyed popularity in the United States, England, Holland, and other countries for centuries. Numerous Dutch Colonial style homes in the U.S., dating back to the 17th and 18th centuries, have gambrel roofs that allowed attic space to serve as additional bedrooms. Builders, farm owners, and ranchers still use similar designs in modern homes, although gambrel garages, storage sheds, outbuildings, carriage houses, and barns are now the most common buildings to use gambrel roofs in the United States.
Building a traditional gambrel garage from scratch involves more complex roof rafter requirements than gable roofs, with additional purlin beams and dovetail joints where the lower panes fit to the top panes. Simple designs using trusses and steel joiners are available. Some gambrel garage or outbuilding designs can be purchased in prefabricated kits for easier assembly by homeowners. Regardless of the method of construction, gambrel garages are favored for the extra storage space gained in comparison to the minimal extra cost of additional lumber and supplies.