Session: Green Buildings I

Model-Based LCA on Stanford’s Green Dorm
Jennifer Tobias,^*   Stanford University
John Haymaker,   Stanford University

Architecture, Engineering and Construction (AEC) professionals want to use Life Cycle Assessment (LCA) as an integral part of design, but are hampered by a complex process, limited data, and insufficient tools. Model-based tools, such as LCADesign developed by the Australian Cooperative Research Centre for Construction Innovation, promise to help AEC professionals more easily perform and communicate LCA. The prototype LCADesign calculates the embodied environmental impacts from a 3D building information model represented in the global standards-based Industry Foundation Classes (IFC) format. Industry case studies are being conducted to evaluate whether such model-based LCA helps make environmental analyses a more integral part of AEC design.

This paper describes the application of LCADesign to determine the impacts of the Stanford Green Dorm, a 47-student residence and living laboratory. Of key interest are the impacts arising from the choice of wood or innovative steel rocking frame structural systems. We explain the analyses of these two design options, including the modeling of 3D geometry, and customization of local supply chains to improve the accuracy of the data. Our initial analyses found wood to be the environmentally preferred choice. However, with the high likelihood of earthquakes in the region, the design team broadened the scope to include likely seismic impacts. The Blume Center for Earthquake Engineering at Stanford University provided the required data to estimate the damages from an earthquake. We modeled the replacement materials, and performed a second assessment. In this iteration, contribution results showed steel to be the environmentally preferred choice. In subsequent design phases, the design team will investigate steel-wood hybrid systems to maximize the contributions from the durability of steel and the low environmental impacts of wood.

We discuss the strengths and weaknesses of the model-based process from the AEC designer's perspective. LCADesign easily allows the modification of building geometry and calculation and visualization of results. This iteration and real-time information enables LCA to become a more integral part of the design process. We address data quality and transparency issues that otherwise would remain an issue that reduces designers' confidence.

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