Intelligent Sustainable Design: Integration of Carbon Accounting and Building Information Modeling

Buildings embody and consume among the largest fraction of energy within the built environment, and likewise they are responsible for large emissions of greenhouse gases (GHGs), often referred to as their carbon footprint. From smalland medium-sized buildings to the most energy intensive of structures, architects and engineers are faced with many new challenges in designing and retrofitting buildings for reduced energy and GHG intensity. Engineers and environmental scientists have been examining the embodied energy and related carbon emissions of buildings for more than 40 years (Baird and Chan 1983; Buchanan and Honey 1994; Cole 1998; Venkatarama Reddy and Jagadish 2003; Nassen et al. 2007; Kellenberger and Althaus 2009), yet arguably few undergraduates recognize this research as a basis for sustainable design. As sustainable and “green” design has become more prevalent in the architecture and engineering industries, college graduates must be prepared not only to follow environmental guidelines but also to understand the implications as well. After more than two decades of research into “greening” the design and construction of buildings, many new methods and tools have emerged to meet the energy challenges of the built environment. Residential and commercial buildings in the United States currently consume about 40% of the country’s primary energy and emit 20% of the national carbon dioxide budget (Yeang 1999; Yudelson 2007; Dimoudi and Tompa 2008; U.S. Department of Energy 2009; U.S. Energy Information Administration 2010). Thus, one major focus of sustainable building design is to reduce the carbon intensity of building components as well as lower operational energy demand (Kellenberger and Althaus 2009). Courses that focus on sustainability are becoming integral within higher education as part of greenand sustainable-engineering undergraduate programs (AASHE 2010). Within the civil engineering discipline, life-cycle assessment (LCA) has become an important analytical framework for evaluating the environmental sustainability of civil engineering infrastructure. Moreover, for architectural engineering specifically, building information modeling (BIM) is evolving as a valuable tool for meeting sustainability objectives in building programs. This paper discusses the experience of combining BIM and LCA methods in undergraduate and graduate engineering teaching at Drexel University and the application of commercial BIM and LCA software for teaching sustainable design of buildings.