At first glance, those original wood windows in your pre-1940s house may seem like a significant source of air leaks and heat loss. Maybe you think the best way to save energy and money would be to replace your original windows? Look again.
Studies have shown that most homes lose more heat through the roof and un-insulated walls than through windows. The payback on your energy bill for your “investment” in new windows can be in terms of decades (that’s assuming your new windows actually last that long – they won’t). Original wooden windows in the northwest were constructed of individual components of old-growth fir, which makes them easy to repair and generally less prone to rot and warping than modern pine windows. And vinyl replacements, even a high-quality vinyl window, still can’t hide the fact that it’s made from… well vinyl (PVC) – a material known for its toxic lifecycle.
Original windows are often a character-defining feature for many older Portland homes and some replacement windows may not be able to meet design guidelines for historic properties. To overcome the limitations of the single-pane wood window such as sound or heat loss, consider storm windows (interior or exterior). Adding a storm window to a single pane window system can lower heat loss by 50%. And don’t forget the embodied energy of your existing windows - the energy required to extract, manufacture, transport, and install. This embodied energy is lost when you remove your original windows and the cycle starts all over for new ones.
So, if you really want to save energy, money, and the integrity of your home’s character, stop looking at your windows… and start looking through them. For more information, visit “The Window Replacement Dilemma” section of our Sustainable Preservation web page or call the Regional Green Building Hotline at 503-823-5431.