Windows are a principal character defining feature of a building and serve both functional and aesthetic purposes. Windows allow the interior of a building to receive natural light, provide a means to see from the inside of a building to the outside and allow ventilation of a building interior.
The size, location, type and trim of windows are a defining element of historic architectural styles. The proportion of a building facade made up of windows is also an important architectural design element. For example, early-19th century structures generally have a smaller amount of window area than do buildings from the 20th century. Muntin size is also an important indicator of the architectural heritage of a building. Thin muntins are associated with Federal style structures, while wider muntins generally indicate a later 19th century building.
Window trimwork or surrounds also help to define the historic architectural style of a building. For example, Italianate buildings often have deeply molded curved surrounds or hoods on upper story windows; Colonial Revival style buildings usually have relatively simple wood or brick sills and lintels.
In general, the windows on 18th century buildings in Alexandria were small with small sized panes of glass. By the middle of the 19th century, technology permitted the manufacture of large size panes of glass. This enabled windows on Victorian era structures to have large expanses of glass, some without muntins.
The popular Colonial Revival architectural styles in the 20th century employ multi-pane windows with small panes of glass often with a single light below. Bay windows were not used until the late-19th century; however, they are a well established part of the Colonial Revival design vocabulary.
Changes to windows can have a dramatic impact on the historic appearance of a structure. Many buildings in the historic districts have had the windows changed in an attempt to alter the historic period of the structure or to create the appearance of modernity. For example, the large paned one-over-one or two-over-two windows typical of wood vernacular Italianate row dwellings have been replaced with small paned six-over-six windows in an effort to Federalize a structure. Similarly in the late 19th-century, windows in many wood vernacular Federal style buildings were updated by the installation of large paned windows and Victorian era detailing on the window surrounds.
RETENTION OF HISTORIC MATERIALS
A central tenet of the philosophy of historic preservation is that original materials should be retained and repaired rather than replaced. An informed and careful analysis of the existing condition should be made before any decision to replace historic materials is made. It is often cheaper to keep historic materials and repair them rather than replace and item with new material. Storm windows or new weatherstripping will make a historic sash quite efficient without replacement.