The Effect of Panelized Single Family Residential Construction on the Environment

Abstract

12 pagesThe construction of single family housing in the U.S. 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 a greater or a reduced impact on the environment? This paper analyzes the 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 or stressed skin insulating core panels, in terms of material use, waste generation in construction, and energy use in operation. One experiment measured the energy consumption of 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 indicated that the more completely components are factory fabricated, the less energy a house built from these components will consume, resulting in reduced CO2 emissions from burning fossil fuels. The units built with more industrialized panels had a more complete insulation envelope and half the air changes per hour. Another test compared conventional on site construction (wood frame) to stressed skin insulating core panel construction. Stressed skin insulating core panel construction used 5% less total wood and 50% less framing lumber, indicating the consumption of fewer trees. A similar experiment comparing the side by side construction of a wood frame house to a panelized house showed less solid sawn lumber used and less waste generated on site by the panelized house construction. A recent prototype panelized floor/foundation system showed promise as a lower cost alternative to concrete slab construction with its high embodied energy. The on-grade panel floor system has a better thermal performance than a typical slab floor, and the panels can be reused upon demolition. These examples show that high levels of industrialization can potentially result in less environmental impact from construction, operation, and demolition