Windows are a character-defining feature of buildings in Georgetown, serving both functional and aesthetic purposes. The type, size, location, material, glazing, and trim of windows help define a building’s architectural style and changes to them can have a dramatic impact on a buildings appearance. Collectively, windows define the historic aesthetic and character of Georgetown and preservation of historic windows is key to maintaining this character.
The Old Georgetown Board (OGB) is committed to preserving historic windows, especially those that are difficult or impossible to replace with old growth wood, hand-blown glass, or unique details. It is the Board’s policy that windows installed prior to 1950 be restored where possible. Old Georgetown Board staff will make a determination on the age, condition, and type of windows in question, supported by appropriate documentation supplied by the applicant.
Where historic windows to do not exist, or are deteriorated beyond repair, the OGB supports replacement windows that are in keeping with the style of the building and in materials compatible with the historic district. Generally, this means wood, single-glazed, true-divided light windows on street-facing elevations. The Board is committed to sustainability and supports simulated divided light replacement wood windows on non-street facing elevations. Interior storm windows or energy panels are acceptable where insulated glazing is not appropriate. High-quality fiberglass, aluminum-clad wood, and metal replacement windows are generally acceptable on non-street facing elevations of buildings or additions constructed after 1975, when these materials came into more widespread use.
The OGB recommends that replacement windows be compatible with the style of the building. Unfortunately, the windows on many buildings in Georgetown have been replaced with stylistically inappropriate windows in an attempt to make the building appear older than it actually it is. A typical example are Victorian-era buildings that originally were constructed with large two-over-two or one-over-one windows that have since been replaced with six-over-six Federal style windows, typically in the mid-twentieth century. In these instances, the OGB prefers that windows be replaced to match the original design, however, sometimes the facade has been altered so greatly or the context of the alterations is significant enough that the OGB may recommend restoration or replacement in-kind of the multi-light windows.
• Visible vinyl jamb liners are discouraged. If your window manufacturer does not offer authentic wood jambs, consider a single-hung window without the lower jamb liner or wood jamb liner covers.
• If historic wood frames and brickmold exist, the OGB will require these be retained and restored in place. If the sashes are not historic or deteriorated beyond repair, the OGB typically prefers to see replacement sash kits that do not contain a sub-frame. The use of a sub-frame (often called “insert” or “pocket” windows) decreases the total glazing area, thus altering the style and aesthetic of the house. High-quality, paintable fiberglass insert windows are acceptable on buildings or additions constructed after 1975, if it can be shown the jamb tolerances are minimal.
• Interior screens are preferred, however if exterior screens are desired, half-screens with a highly transparent mesh are acceptable, whereas full screens are not permitted.
• Muntins should always have a putty profile. Staff can help you determine the appropriate muntin width and light configuration for replacements. If simulated divided light and double-glazed replacement windows are proposed, the window must have an internal spacer bar in a mid-tone color. Between-the-glass or “sandwich” muntins are never appropriate.
• All replacement glazing should be clear and untinted without reflective coatings. If using Lo-emissivity (LoE) coatings, the OGB recommends a lower emissivity coating be used to avoid tinted hues or reflectivity; glass designated with LoE 100 or 200 series generally meets this requirement.
The Board recommends regular maintenance of windows to increase their longevity. This includes regular painting, caulking, and weather-strip replacement, as necessary. If your windows are historic, it is recommended that you seek the services of a qualified window restoration specialist with the skills and knowledge to work with historic glass and mortise-and-tenon joinery. Qualified restoration specialists are also often equipped to deal with lead paint and other hazardous materials sometimes encountered with historic building materials.
• The Secretary of the Interior Standards for Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, & Reconstructing Historic Buildings
• District of Columbia Historic Preservation Office Window Repair and Replacement Preservation and Design Guidelines
• Submission Requirements for Old Georgetown Board