If eyes are the windows to the soul, then windows must be the eyes of the home. They are key to the face – or façade – of a historic home as much as eyes are to the face of a person.
Repairing or replacing windows while keeping their historic character is key to maintaining your historic home. It’s also the law. In the historic district, a window replacement may need District approval.
The Capitol Hill Restoration Society (CHRS) and the DC Historic Preservation Office (HPO) both begin discussion of historic windows with the same question: is replacement actually necessary? CHRS says complete replacement is a last resort, while HPO says historic windows should be repaired unless an owner can document that repair is not reasonable.
It’s a complicated matter, as you can see from the wealth of information out there. CHRS has guidelines on their Capitol Hill Historic District Guidelines page and two linked booklets, Windows: The Eyes of a Building and Replacement Windows. That series, available at chrs.org/history-and-preservation/chrs-historic-district-guidelines/ was developed to explain the District’s important characteristics and advise owners about maintenance, CHRS said.
So how to repair a window that could be a century old? When is it necessary to replace the window? For an owner who has reached that threshold, how does one replace the window without changing the proportions, depth and details that make it part of the character of the house?
Look at Each Window
It might be a relief to know that it’s likely not every window in the house needs the same treatment.
The window sash is the structure holding the window glass inside the window frame. Sometimes there are two, one capable of sliding behind the other; the sash may also open out, or have separations called muntins that hold smaller panes of glass. 
Examine each sash, frame, sill, pane, joint and piece of hardware. Note where paint is loose, glazing putty is missing, wood is soft, glass is cracked, sash cords are broken or the sash no longer fits its opening. Just as when brick or plaster is damaged, if a wood frame or sash shows water damage, find the source of water before repairing damaged wood. Otherwise a leaking gutter, failed sill joint or missing paint could ruin a costly repair.
HPO’s illustrated Window Repair and Replacement Guidelines make a distinction between deterioration and total failure. Like CHRS, HPO recommends owners keep and repair historic windows, replacing only when the condition of the window makes repair impossible. A replacement can reproduce some of the original appearance, but it cannot preserve the original fabric, CHRS argues.
A practical assessment should answer three separate questions: Can the problem be repaired? Can a deteriorated sash be replicated while the frame remains? Has the frame or the entire window assembly failed? You can ask a restoration contractor to price those options separately. VITMAR Restoration (vitmarrestoration.com), a Rockville contractor serving DC’s historic neighborhoods for more than twenty years, offers repairs to glass, glazing, hardware, weatherstripping and mechanical systems. They can also fabricate a replica sash when the original is beyond repair. Their lengthy menu illustrates why a faulty component does not automatically require a whole-window replacement.
Window Repair Can Solve Problems
Reglazing, caulking, weatherstripping, consolidating deteriorated elements and installing new hardware are routine window repair according to HPO. These ordinary repairs, along with replacing a broken pane, do not require a building permit or preservation review according to agency guidance.
Replacement is different and generally requires a permit on designated historic property. Owners should confirm the scope with HPO and the Department of Buildings (DOB) before work begins.
A repair should address the defect rather than merely cover it. A stuck double-hung sash may need paint carefully removed from its joints and channels. A sash that will not stay open may need new cords or chains connected to its counterweights. Loose or missing glazing putty can be removed and renewed so glass is secured. Cracked panes can be replaced but good historic glass left in place. Local and DMV restoration firms also describe repairing minor decay with wood consolidation or fitted wood repairs,. They can also renew failed paint, restoring locks and pulleys, and adding weatherstripping.
The finished work should leave the sash operating smoothly and protect exterior wood with compatible primer, paint and glazing. Many window drafts are due to space around the window rather than to faults with the window itself. HPO’s 2025 Sustainability Guide recommends maintaining and weatherstripping historic windows and considering compatible interior or exterior storm windows. That approach can improve comfort without discarding the sash. If work disturbs paint in a pre-1978 house, the US Environmental Protection Agency (EPA) requires contractors to follow its lead-safe renovation, repair and painting rules.
When to Replace
Replacement may be justified when deterioration is so extensive that the sash or frame cannot provide a sound repair, when important pieces are missing, or when a previous replacement is itself inappropriate. Alex Szopa, owner of Windows Craft Inc. www.windowscraft.com), has been working on Capitol Hill for over 25 years, and his specialty is historic windows and doors. Originally from Poland, he brings a knowledge of Europe’s centuries-old buildings to the Hill’s hundred-year-old homes. “I work with Capitol Hill residents to preserve the beauty and historical nature of their home,” says Szopa. “Often replacement, when done by experts, is a better investment than refurbishing the window.”
Szopa is happy to explain the difference in cost and effect on your project. You should require the contractor to document the condition with close photographs and explain why partial repair or sash-only replication will not work. HPO may ask for that evidence, particularly for a window on a historic building that is visible from public space.
Divided-light windows, those with multiple panes of glass held in place by muntins would ideally actually be separate panes of glass. Simulated divisions with permanently applied muntins on both the exterior and interior are permitted. But District standards do not accept removable snap-in grids or grids sealed only between panes as substitutes for historic divided windows. CHRS advises against vinyl or aluminum replacements in the Capitol Hill Historic District and recommends replicating seriously deteriorated elements in their original materials. The relevant question is not whether a material is universally allowed, but whether the window unit is appropriate for that building and location.
Cross Your Muntins
Check the address in the District’s Scout property database or contact HPO to determine whether the house is designated as historic. For replacement on historic property, consult HPO before ordering a new window –review before you order! Submit photographs of the window and full elevation along with drawings or product information showing dimensions and profiles. HPO can clear compatible replacements through staff review. Proposals that do not meet the standards may go to the Historic Preservation Review Board (HPRB).
A contract should identify each window and state whether the work is maintenance, sash repair, sash replication, insert replacement or removal of the complete frame. It should assign responsibility for permits, glass, hardware, trim, plaster, paint, lead precautions and weather protection. VITMAR cautions that some restoration specialists work only on the sash and leave surrounding casing, plaster and paint to someone else, so define the terms before signing or paying.
In a 2021 Hill Rag article, longtime Capitol Hill homeowner Rindy O’Brien advised residents to make a maintenance plan and noted the value of vendors who understand Capitol Hill and its historic rules. That principle is especially useful. Seek bids from contractors experienced in historic sash, not only companies selling replacement units; check licensing, insurance and references; and compare the approved drawings with the delivered work before installation. Repairing first, and replacing only what cannot be saved, protects both the house and the homeowner’s options and prevents your repair or replacement from disfiguring the eyes into –and out of –your home.
