Born out of the fundamental need for shelter, National-style homes, whose roots are set in Native American and pre-railroad dwellings, remain unadorned and utilitarian. The style is characterized by rectangular shapes with side gabled roofs or square layouts with pyramidal roofs. The gabled-front-and-wing style pictured here is the most prevalent type with a side-gabled wing attached at a right angle to the gabled front. Two subsets of the National style, known as "hall-and-parlor family" and "I-house," are characterized by layouts that are two rooms wide and one room deep. Massed plan styles, recognized by a layout more than one room deep, often sport side gables and shed-roofed porches. You'll find National homes throughout the country.

Source: National Association of Realtors