Energy Consumption and Greenhouse Gas Emissions Related to the Use, Maintenance, and Disposal of a Residential Structure

Virtual residential houses in Atlanta, Georgia, and Minneapolis, Minnesota, were analyzed to determine energy consumption and greenhouse gas emission during the building use, maintenance, and demolition phases of their life cycle. An analysis of Census data on housing stocks provided estimates for the useful life of a house. Home Energy Saver, an internet tool for energy analysis sponsored by the Department of Energy and available from the Lawrence Berkeley National Laboratory, was the primary tool used in assessing energy consumption for heating and cooling during the use phase of the buildings. A survey on the life span of house components by the National Association of Home Builders (NAHB) was used to estimate a maintenance/replacement schedule. Emissions during demolition and transport to the landfill were estimated based on the initial bill of materials in the house and distance to the landfill. The energy consumption over a 75-year life was estimated to be 4,575 GJ for the Atlanta wood frame, 4,725 GJ for the Atlanta concrete block structure, and 7,800 GJ for the Minneapolis wood frame. A steel-framed Home Energy Saver model was not available, but since the steel-framed house was designed to code for equal thermal properties with the wood frame house, we assume no difference. Energy consumption related to structural/exterior maintenance was estimated at 110.5 GJ for the Atlanta location and 73.3 GJ for Minneapolis, only 1–2% as large as used for heating and cooling. The energy needed for demolition and waste removal was even smaller. Carbon dioxide (CO2) emissions from the consumed energy were estimated using the regional energy grids in SimaPro at 227,000 kg (501,000 lbs) for the Atlanta wood frame, 235,000 kg (519,000 lbs) for the concrete frame, and 338,000 kg (856,000 lbs) for the Minneapolis wood frame. CO2 emissions related Wood and Fiber Science, 37 Corrim Special Issue, 2005, pp. 128 – 139 © 2006 by the Society of Wood Science and Technology to structural (primarily exterior) maintenance were 4143 kg and 3468 kg, respectively, for Atlanta and Minneapolis. The emissions from deconstruction and waste removal were roughly 1/10 that of maintenance. Reducing energy consumption during building use provides a major opportunity to reduce environmental burdens. When time-valued discounting over the building life is considered, reducing the burdens associated with product use and construction is equally important.