Windows serve as more than functional components of a building that provide light, ventilation and view. Windows are a character- defining detail of an historic building. Windows are also one of the most important aspects of a building’s material fabric and historic appearance. The design of a window is as important as any other decorative element. Windows provide insight to the age of the house, demonstrate architectural styles or construction techniques of a region or period, reflect changes to the building, and are often exceptional examples of craftsmanship or design.

The reasons listed above may be good cause for preservationists to advocate for keeping them, but may not be good enough reasons for everyone else. The number one reason building owners consider replacing their windows is because of energy efficiency. While energy savings is “green,” the vehicle toward its achievement is often the antithesis of “green.” Consider the following if you are thinking about replacing your windows:

• Windows account for only 10-20% of heat loss in a building. The majority of heat loss is through attics, floors, and chimneys.
• The average return on investment for replacement windows is 30-40 years. Insulating the attic, floors and walls has a return on investment is 3-5 years.
• A single-pane window with a storm window is as energy efficient as a replacement window. There are many different types of storm windows available and laminated glass is a great alternative to insulated glass.
• Energy efficiency is related to more than energy consumption; it is related to many other ways of using energy.
• The typical life cycle of a replacement window is between 10-15 years. The life cycle of original wood windows, if property maintained, can last hundreds of years.
• Many of the materials that are used in manufacturing replacement windows—aluminum, vinyl, and glass—are among the greediest in terms of energy consumption, resource depletion, inability to recycle, and require significant energy to transport since many are not made locally.
• All of the original wood windows that are being replaced end up taking up space in a landfill.
• Vinyl windows are made with PVC, a plastic that many consider one of the most toxic in the environment.
• Windows built before 1950 were most likely constructed of milled heartwood or old-growth wood, which is more dense and durable than wood available today. If properly maintained, an original wood window can far outlast any replacement.
• Historic wood windows are designed to allow a single component to be repaired when it fails whereas modern replacements are not. The cost of repair is often just as expensive as replacing the entire unit.
• Most people can do window repairs themselves and the supplies are available at local hardware stores. If you are interested in learning how to do repairs look for our Windows Workshop later this Spring!Replacing glazing putty, glass, sash cords and weather- stripping can be done at a cost equal to or less than $1 per linear foot.
• It is less expensive to restore all of a building’s windows than to replace them. It is extremely rare that ALL windows of a single building fail at the same time. Repairing and maintaining individual windows as they need work is most cost-effective. The advantage of repair is that it can be easily phased to spread the work and cost over time, as permitted by weather and budget. It is far easier to repair a few windows than it is to replace the windows of an entire building.
• Lead paint on the windows does not mean they are unsafe or that they should be replaced. There are effective protective measures available that can be taken.
• Hiring a local craftsman helps to support your community’s local economy.

If you are interested in resources or more information, please contact the Foundation (518) 587-5030.