Methodology for the integration of environmental and economic impacts used in the dynamic determination of the sustainability of residential building materials

Abstract

Substantial environmental impacts come from the construction and operation of buildings. As of 2006, the US Geological Survey found that more than 75% of the raw materials (by weight) consumed in the United States were used for construction. Additionally, home and commercial buildings consume 70% of electricity and emit 40% of the greenhouse gases in the US, according to the US Department of Energy. Improvements to buildings through more efficient materials could dramatically change the world's energy consumption.

The goal of this research is to conduct a Life Cycle Assessment (LCA) and a Life Cycle Costing (LCC) analysis on various components in homes to determine which materials selections are best in terms of the environment, cost, and overall sustainability performance for the lifetime of a home. All phases of the life of a product are considered; including resources, manufacturing, installation, end-of-life, and most notably, use. Housing components chosen for the study can be retrofitted in an existing home and can make a significant impact on the energy or material use of a home. The housing components studied include flooring, windows, roofing systems, and wall insulation. Energy use was modeled for the windows, roofing systems, and wall insulation studies for a standard single-family home in 17 different US cities, representing all of the climate zones in the US. The energy consumption information was used to determine how using different materials as well as efficiency increases for a material, such as increasing R-value, could affect the environmental impacts and economic impacts over the lifetime of a product and a home. Retrofitting windows, roofing systems, and wall insulation can greatly impact the energy demand of a home for heating, ventilation, and cooling, leading to lower environmental and economic impacts. While flooring does not directly impact the home's energy demand for heating and cooling, flooring's environmental impacts over a lifetime can be attributed primarily to flooring maintenance, particularly when the maintenance involves vacuuming.

This study asserts the crucial link between the use phase of housing components on the environmental, economic, and sustainability performance of a home. It establishes a sustainability metric which can be utilized by developers, homeowners, or manufacturers to understand the performance of a product employed in a home over the time frame the home is in operation. The developed framework can be employed to look at any components within a home. Additionally, the study investigates the importance of location and climate zone on these results.