“There is an epidemic spreading across the country. In the name of energy efficiency and environmental responsibility, replacement window manufacturers are convincing people to replace their historic wood windows. The result is the rapid erosion of a building’s character, the waste of a historic resource, and a potential net loss in energy conservation. Typically replacement windows are vinyl, aluminum, or a composite with wood, and none will last as long as the original window. Repairing, rather than replacing, wood windows is most likely to be the “greener option” and a more sustainable building practice.”
So begins the introduction to a new Tip Sheet available on-line from the National Trust for Historic Preservation entitled “Historic Wood Windows”. The four-page publication has information ranging from why retaining wood windows is more cost- and energy-efficient than modern replacements, maintenance information, lead paint concerns, and references great resources for additional, in-depth information. To download your free copy go to: http://www.preservationnation.org/issues/sustainability/additional-resources/July2008WindowsTipSheet.pdf
Windows are a primary character defining feature of a historic home, yet are at the most risk for wholesale replacement during home renovation projects because homeowners don’t know how easy they are to repair. The result is often a costly project that diminishes the historic character of the home and actually increases long term maintenance and replacement costs. This is because most modern windows touted as “maintenance free” are actually better described as “unable to be maintained”. Unlike historic wood windows that can be repaired to function indefinitely, most modern windows have an anticipated life span of twenty years. After this time, the spring mechanisms give way and the seals around the glass fail, often causing condensation or fogging on the panes. Added to this, if the glass and/ or frame of a modern window is damaged by a projectile, the unit generally requires a factory repair or total replacement. Compare this to a historic wood window that can be repaired by a handy homeowner or a local woodworker when the weights let loose, a pane is broken or sash rots.
Another common fallacy about replacement windows is that they will save dramatically on energy costs. While most modern replacement windows offer a higher R-value than traditional windows, the resulting energy savings do not cover the costs of the replacement windows within their twenty year service-life. Other energy savings projects such as insulating the attic, adding weatherstripping around windows and doors, adding shading devices such as awnings and installing solar powered attic fans are better energy saving investments that don’t result in the loss of historic fabric of the home.