Based in California, Siegel & Strain Architects is an award-winning design firm that specializes in architecture, sustainability, historic preservation, and research. Though the firm has had a strong environmental focus for many years, it has only recently begun to use BIM-integrated life-cycle analysis tools to gain a better sense of its projects’ environmental impact, specifically carbon emissions. “We have been working to understand embodied carbon emissions since 2009,” says the firm’s founding partner Larry Strain. “We think that this LCA tool will help us achieve this understanding with a higher degree of accuracy.”
Siegel & Strain’s most complete LCA analysis was conducted on a highly insulated, high-performance research facility at the University of California, Davis. The 8,500-square-foot, zero-net-energy building was completed in 2013, but the design team decided to use BIM-integrated LCA as part of a post-building assessment to understand the global warming potential of its materials. In addition to evaluating the embodied environmental impacts of the steel and concrete that were primarily used in the building’s construction, the team also wanted to examine the long-term implications of the large amounts of polyisocyanurate foam insulation that made the building so thermally efficient and helped it achieve its zero-net-energy status. While this foam was successful in increasing the facility’s operational efficiency, the LCA report revealed a huge embodied carbon impact associated with its manufacturing process. “Looking at the project’s life-cycle tradeoffs, we are now questioning the use of such large amounts of foam to achieve net-zero-energy status,” Strain said.
Though working with a BIM-integrated life-cycle analysis tool was not Siegel & Strain’s first experience with LCA, other methods the firm used in the past came with some disadvantages. “In 1997, we hired a consulting firm to conduct an LCA of an affordable housing project we were designing,” Strain says, but he notes that “we were somewhat overwhelmed by the amount of data we received, and it was difficult to draw conclusions from the results.” To simplify the process, the firm conducted its own LCA of a town center project using the Inventory of Carbon and Energy (ICE) database. While this LCA was much more straightforward and easier to understand, Strain says that it was also “very labor intensive compared to using a BIM-integrated life-cycle analysis tool.”
In contrast, Strain explains, this automated tool provided the simplicity of an in-house LCA but with even greater utility to design than an LCA consultant. “The interface was surprisingly comprehensive and simple to use,” Strain says. “It enabled us to quickly identify objects and subsystems within our Revit model that we wished to include in our analysis and made the process of assessing the LCA data very palatable.” Strain also adds that the functionality “extends beyond merely providing a tool for itemizing building components and has proven to be a valuable design and analytical resource.”
Having used a BIM-integrated life-cycle analysis tool for a post-building assessment, Siegel & Strain now looks forward to using it during the design phase of future projects in order to make better material choices in its projects, such as a new 50-unit net-zero housing development project. Strain says, “The client has expressed an interest in having us track the embodied global warming potential for the development so that we can work toward net-zero-energy status for the full life cycle of the project, instead of just the occupancy and operations phase. This tool will help us to better understand and lower the embodied carbon emissions of our projects, and also disseminate what we learn to the design and construction industry.”
Source: Larry Strain, Siegel & Strain Architects
Walter P Moore is an award-winning structural engineering firm headquartered in Houston. Understanding that creating sustainable designs is one of the foremost challenges of the building sciences today, the firm values sustainable solutions that can be integrated for high-performance buildings and infrastructure. It is this commitment that led its team to incorporate a BIM-integrated life-cycle analysis tool into the structural design process of a two-story, 18,000-square-foot office building for an independent research hub.
Located in The Woodlands north of Houston, this research facility was designed by Gensler to be the headquarters for the Houston Advanced Research Center (HARC). Because HARC works to illuminate and address problems surrounding air quality, clean energy, and water quality and supply, it’s important that its headquarters not only provide office space but also exemplify the sustainable technologies to which the research hub dedicates itself. To meet its client’s sustainability goals while also targeting a LEED Platinum rating, Walter P Moore used a BIM-integrated life-cycle analysis tool to conduct a whole-building LCA that both minimized the research facility’s embodied impacts and earned the building LEED Whole Building LCA credits.
Beginning in the project’s schematic phase and continuing throughout the design development phase, the structural design team used the LCA tool to compare different structural systems and investigate which assemblies and subassemblies were the most environmentally impactful. “Because ‘steel’ buildings contain a significant amount of concrete and ‘concrete’ buildings contain a significant amount of steel, we found that the most effective reductions occurred within subassembly optimizations,” says Dirk Kestner, Walter P Moore’s director of sustainable design. This focus led the team to an early realization that concrete and, more specifically, the Portland cement in concrete contributed most significantly to the entire building’s embodied environmental impacts. With this information in mind, the team reduced the use of concrete overall and specified that the remaining concrete should more efficiently use Portland cement. Doing so achieved more than 15 percent, 20 percent, and 25 percent reductions in the LEED categories of Smog Formation Potential, Global Warming Potential, and Acidification Potential respectively.
In addition to reducing embodied environmental impacts, the software also facilitated communication between the various groups within the project’s team. “It’s important for the full design team and the contractor to understand the LCA goals for the project prior to beginning the Construction Administration phase,” Kestner notes. Because the results are output directly into clear and legible graphs, there’s very little translation needed between different project groups. This in turn allows each of a project’s groups to have more input during the design and construction process. “It was very helpful to have a contractor involved in the schematic LCA discussions,” Kestner says, adding that its contractor’s involvement helped the entire project team “understand possible cost and scheduling ramifications.” Additionally, involving the full project team in an LCA conducted as early as possible in the design phase allows the LCA to be “routinely monitored and refined as the design progresses,” says Kestner, who also notes that contractors specifically can “ensure that the material assumptions made in a whole-building LCA are followed during procurement.”
Source: Dirk Kestner, Walter P Moore