Abstract

New windows are rated based on their energy performance during the use phase and neglect the overall environmental impacts caused by manufacturing, maintenance, and disposal. Due to the number of residential window replacements occurring today in the United States, there is a growing need to quantify the sustainability of window preservation as an alternative to window replacement. This study assesses the environmental impact of wood window restoration versus replacement with vinyl windows, aluminum-clad wood windows, and wood windows for the entire “cradle to grave” life cycle of the window assembly. Modeling a historic house located in a Philadelphia suburb, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts of historic wood window restoration versus window replacement for a building service life of 75 years. The life cycles were modeled using GaBi Software and inventories were analyzed using TRACI 2.1 which translates the environmental consequences of the LCA processes into quantifiable environmental impacts. The results indicate that wood window restoration has less overall environmental impact when compared to replacement windows. Window lifespan and building service life assumptions impacts the results and demonstrates the importance of proper wood window maintenance.