Many of the residences in this category are difficult to distinguish without inspecting the interior, since all have symmetrical facades parallel to the ridgeline of the roof. You can generally recognize a double cell by its even number of door and window openings (in contrast to the single-cell and hall-parlor types), and central-passage houses are usually (but not always) larger than those with a hall-parlor plan. BUT—only the specific floor plans truly identify these types.
The remaining types, including the side-passage house with its distinctive offset door, can all be identified by their exterior appearance.
In an effort to demonstrate the stylistic and compositional variety found within each category, we offer several examples of each house type.