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Whenever possible, repair a historic window, rather than replace it. In most cases it is in fact easier, and more economical, to repair an existing window rather than to replace it, because the original materials contribute to the historic character of the building. Even when replaced with an exact duplicate window, a portion of the historic building fabric is lost and therefore such treatment should be avoided. When considering whether to repair or replace a historic window, consider the following:

Architectural Significance

First, determine the window’s architectural significance. Is it a key character-defining element of the building? Typically, windows on the front of the building and on sides designed to be visible from the street, are key character-defining elements. A window in an obscure location, or on the rear of a structure may not be. Greater flexibility in the treatment or replacement of such secondary windows may be considered.



Second, inspect the window to determine its condition. Distinguish superficial signs of deterioration from actual failure of window components. Peeling paint and dried wood, for example, are serious problems, but often do not indicate that a window is beyond repair. What constitutes a deteriorated window? A rotted sill may dictate its replacement, but it does not indicate the need for an entire new window. Determining window condition must occur on a case-by-case basis, however as a general rule, a window merits preservation, with perhaps selective replacement of components, when more than 50 percent of the window components can be repaired.

Appropriate Treatment


Third, determine the appropriate treatment for the window. Surfaces may require cleaning and patching. Some components may be deteriorated beyond repair. Patching and splicing in new material for only those portions that are decayed should be considered in such a case, rather than replacing the entire window. If the entire window must be replaced, the new one should match the original in appearance.

3.0 Windows, Design Guidelines for Residential Historic Districts in Salt Lake City, Salt Lake City Historic Landmark Commission, Salt Lake City Corporation, 1999.

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