The U.S. Secretary of the Interior's Standards for the Treatment of Historic Properties and the D.C. Historic Preservation Office's Window Standards maintain that the repair of original windows in designated historic buildings is preferable to their replacement. Keeping these windows promotes the long-term preservation of the physical fabric, historic integrity, and appearance of the building. The Old Georgetown Board (OGB) supports this position.
There are other benefits to preserving historic windows. For example, historic windows are typically made with significantly higher quality naturally grown old-growth wood, where the wood matured slowly and incorporates dense and compacted growth rings. New wood windows, on the other hand, must rely on preservative coatings that do not endure over time. Original glass represents historic character due to its reflective patterns of unique individual panes. New glass has a flat, plate-glass appearance, and insulated glass also takes on a mirrored look. The insulation function, moreover, only remains as long as the seal holds. A new window unit or sash that requires additional trim to fill a gap between it and the existing window opening or frame is not considered an acceptable replacement.
Sash Replacements:
A permit review submission for the replacement of window sashes must include, in addition to the basic requirements for a permit review submission, the following documents:
- a survey of each existing window to be replaced, with photographic documentation, a written description of the present condition, and detailed drawings of the profile of the sash and muntins
- information about the proposed replacement sashes, with manufacturer's literature on the specific product proposed, and drawings of the new window at each site-specific installation
Frame, Jamb, and Sash Replacements:
A permit review submission for the replacement of windows must include, in addition to the basic requirements for a permit review submission, the following documents:
- A survey of each existing window, with photographic documentation, a written description of the present condition, and detailed drawings of the existing sill, head, jamb, sash, frame, muntin, mullion, shutter, trim, brick mold, and any other distinctive feature for each window proposed for replacement.
- Information on the proposed replacement window units, with manufacturer's literature on the specific product proposed, and drawings of the new window and its site-specific installation, including dimensioned and detailed drawings of the sill, head, jamb, sash, frame, muntin, mullion, shutter, trim, brick mold, and any other distinctive feature for comparison.
Please Note: The applicant or applicant's agent must present the proposal at the OGB meeting. The OGB reviews all proposals on a case-by-case basis, beginning with the premise that historic windows should be retained and repaired where possible.