The environmental impact of panelized single family housing in the United States

The construction of single family housing in the United States is growing increasingly industrialized with panelization emerging as the dominant form of industrialization. Will this trend mean that housing construction, operation, and demolition will have more or less impact on the environment? This paper analyzes differences between low levels of industrialization, such as site built wood framing or open wood frame panels, with higher levels of industrialization, such as closed wood frame panels, in terms of material use and waste generation in construction, and energy use in operation. An example of industrialization's impact on operational resources such as energy was demonstrated in an experiment using six units of housing built using various forms of factory fabrication - open wood frame panels, closed wood frame panels, and stressed skin insulating core panels. The tests showed that the more completely components are factory fabricated the better energy performance they have. In another experiment in which we constructed a single family house, we compared conventional on site construction (wood frame) to stressed skin insulating core panel construction. We determined that stressed skin insulating core panel construction used 5% less total wood and 50% less framing lumber. These two examples show that high levels of industrialization can result in less environmental impact from construction and operation. However, in the case of panels, our survey of U.S. manufacturers indicates that there are a number of barriers to increasing the level of industrialization in panel manufacturing.