While environmentally responsible design and sustainable building practices have become increasingly prevalent in the design and construction industry, decision-making for building products and materials have historically focused on single attributes such as regional manufacturing, recycled content, or consisting of renewable materials or certified wood.
It use to frustrate me that there was not an efficient way to make holistic decisions about building products and materials that incorporated a range of factors, much like we can do regarding building operational energy and water usage. Until relatively recently, the industry has lacked an easily-accessible platform for whole-building life cycle assessment (LCA) – a tool that could integrate into a design team’s workflow and not require esoteric knowledge.
This is starting to change. We are now at the cusp of being able to leverage design performance modeling to conduct environmental impact assessments on whole buildings, manufactured building products, and material assemblies. Thanks to an emerging marketplace of user-friendly analysis tools, architects, engineers, and contractors can now leverage in-depth LCA analyses to compare building materials that both minimize a project’s environmental impact and are more efficient, durable, and valuable to building design and construction. Additionally, because LCA can now be used to earn the LEEDv4 Building Life-Cycle Impact Reduction credit (via Option 4: Whole-Building Life-Cycle Assessment), it is increasingly being adopted and required by clients and project teams pursuing LEED certification.
There are a handful of platforms currently available. The two most popular are:
A joint development project from KT Innovations, thinkstep, and Autodesk, Tally is the first LCA application that allows users to calculate the environmental impacts of a project's building material selections directly in an Autodesk Revit model. Because Tally is Revit-integrated, it integrates seamlessly into the workflow of a project team, making it uniquely positioned to generate data and provide feedback at every design phase.
Learn more at choosetally.com
Athena Impact Estimator for Buildings
Developed by the Athena Sustainable Materials Institute, the Impact Estimator for Buildings allows users to quickly describe building assemblies through dialogue boxes that request simple information such as bay sizes and loads - then the software does the rest. It calculates a bill of materials and the associated environmental impacts. Users have flexibility to add materials as needed. Alternatively, users can import their own bill of materials from any CAD program.
Learn more at athenasmi.org
Both tools can be used to pursue the LEEDv4 Building Life-Cycle Impact Reduction credit.
Using life cycle assessment (LCA) tools such as Tally, design teams can leverage iterative LCA modeling as decision-making tool throughout the design process.
Illustration courtesy of KT Innovations.
A New Kind of Design Performance Modeling
Like any design performance modeling tool, LCA analysis programs will require a learning curve – both in terms of software functionality as well as the technical content being utilized. Of course, these tools are only as reliable as their inputs. Ill-conceived inputs will yield unreliable results. The emerging whole-building LCA tools also support an integrative process, requiring input from multiple disciplines to ascertain specificity with regard to the nuance of the building structure and envelope.
In application, comparing design options in terms of environmental impacts may be a bit confounding. The units of measure may not be familiar to many designers. However, a deep level of understanding with regard to LCA is not essential. Relative comparisons of environmental impact categories from various design options will suffice for documenting improvements for, say, the aforementioned LEEDv4 credit.
This emerging marketplace of accessible LCA tools exemplify the next step in a more substantive dialog about whole-building life cycle impacts. It represents a real shift away from single attribute-based decision-making when it comes to environmentally responsible choices for building products and materials. These tools will only become more robust and they will eventually take on human health considerations and also account for additional impacts, such as on-site energy and water consumption directly attributed to construction.
Let’s boldly move forward to understand the life cycle impacts of our building projects and then improve them in a measurable way.
Excerpt from a whole-building life cycle assessment (LCA) study for a branch library in Indianapolis, Indiana, using the Tally plug-in for Revit developed by KT Innovations, thinkstep, and Autodesk.
Illustration provided by of Browning Day Mullins Dierdorf.