About Dormers

History

• Dormer-style windows have a long history in American architecture. The earliest instances date to the 17th century and Francois Mansart (1598-1666), a French architect known for pioneering Mansard-style hip roofs. Such structures have four sides that angle downward to the walls. Each side has two slopes, the lower of which is much steeper to allow more space inside the attic. Dormer windows extend the functionality of the attic area by permitting light and ventilation as needed.

Function

• The first dormer windows played an essential role in increasing the amount of living space within buildings while respecting height restrictions in Paris. Once the windows were constructed within sloping roofs, it became easier to use attics outside of their traditional function as storage space by repurposing them as extra sleeping quarters. Hence, the name "dormer" from the French verb "dormir," which means "to sleep."

Types

• Dormers come in numerous shapes, sizes and styles, all capable of enhancing a building's visual appearance while augmenting the functionality of attic space. The types range from the fairly simple and common gable style, which has two sloping roofs that meet at a central peak above the window, to intricate polygonal dormers, notable for the multiple openings that allow views in five directions. Other variants include arched, eyebrow, hipped, inset or recessed, pedimented, pyramidal, shed, wall and composite dormers.

Benefits

• Given their broad incorporation across countries and time periods, dormer windows often help define and identify the architectural classification and history of the attached building. The windows also visibly enhance the outer appearance of structures.
  The advantages of adding dormers to a building exceed their typological function and aesthetic appeal, however. In addition, the windows allow light and air to enter a room, which makes the space better suited for habitation.

Considerations

• Dormer windows are an obvious choice to simultaneously increase the attractiveness of a building and the practical usage of attic space. They are essentially an extension of a structure's roof, however, which can create issues if they're situated incorrectly or constructed poorly. If situated incorrectly, this can make the roof of a building look awkward if the windows are either too prominent or not prominent enough. If constructed poorly, it can exacerbate problems related to proper ventilation and lighting.