By Stacy Smedley
Executive Director, Building Transparency
In November of 2019, the Embodied Carbon in Construction Calculator (EC3) tool was publicly launched at the Greenbuild Conference in Atlanta, Georgia. Just eighteen months earlier, the tool had started as a question of how to provide the building community with an easy and widely accessible mechanism to compare manufacturers of like building materials, and assess and select them based on the carbon footprints of their products.
The EC3 tool was co-conceived by Stacy Smedley of Skanska USA Building and Phil Northcott of C-Change Labs, and was incubated as a project of the University of Washington Carbon Leadership Forum with the support of the Charles Pankow Foundation, MKA Foundation, Skanska, Microsoft, Interface, Autodesk and over 50 industry partners in total. Post public launch, a new non profit, Building Transparency, was established to continue to manage, develop and scale the EC3 tool’s use and reach. Since its launch, the tool has steadily increased in number of registered users, currently at over 7,500.
One key item to note is that EC3 is not a whole building life cycle assessment tool and is meant to be a compliment to LCA tools already in use, filling the gap between early LCA design analysis and procurement of building materials, and enabling material manufacturers to compete on cost and carbon.
The process for developing the EC3 tool was and is unique, and continues to inform the tool’s development. Because EC3 is cloud-based, a new release of the tool is pushed out to users every week, with bug fixes, user interface improvements and the inclusion of additional features based on what EC3 users have requested via the UserSnap function built within the tool, as well as via bi weekly calls with EC3 pilot partners. EC3 pilot partners are the tool’s super users and provide deep feedback and guidance on improvements to the tool’s user interface.
The tool’s main features are currently: Find & Compare Materials; Plan & Compare Buildings; Import EPDs; and Manage Data all enabled by a digital database of third party verified Environmental Product Declarations (EPDs) for high impact building materials.
Find & Compare Materials
The Find & Compare Materials feature currently includes the ability to search and sort EPDs for 9 material categories in the public version of EC3. Each material category has distinct performance requirements to filter by, informed by manufacturers and industry organizations from that material sector as well as pilot users of the tool. There is also the ability to sort by location and Product Category Rule, to get a more specific data set of EPDs. There are a number of material categories in “pilot mode” and currently available only to pilot partners, where the EPDs have been digitized and are in the EPD database. The Building Transparency team is working through the process of setting the performance requirements and partnered with the Carbon Leadership Forum to refine material methodology for comparison and category baselines for reduction targets to be set. Once complete, those categories will also push to the public tool. The next categories to release will include Resilient Flooring and Data Cabling, as well as further ongoing refinements to Wood.
The result returned in a search are assimilated into a Boxlplot Diagram that allows a user to see the data aggregated, allowing assessment of their search against the CLF baseline, as well as give them an understanding of the conservative (80th percentile) and achievable (20th percentile) kgCO2e per unit currently available in the supply chain via EPDs.
Users can also then dig into the EPDs returned, and use the tool’s compare feature to view the results at manufacturer vs manufacturer, plant vs plant or product vs product level. This information and assessment can be used by users to inform product selection for specifications, cost estimating basis of design and procurement via sourcing from the lowest emitting manufacturer, indicating a basis of design product or setting a kgCO2e/unit limit that products must be under to meet requirements.
Plan & Compare Buildings
The Plan & Compare Buildings feature allows users to create a project in the EC3 tool, utilizing project specific quantities from cost estimates, Autodesk BIM models or Tally bills of materials. A user can start from scratch or utilize templates the Building Transparency team has created.
Users start by entering project specific data for reference and benchmarking.
Once quantities are entered, users can access the materials searches from within their project planner and assign collections of EPD data to apply. This allows users to start during the design phase and utilize the data to assess what reductions and selections are possible based on current available supply chain EPD data, based on their searches.
This information can be used to focus on highest impact material categories and/or set project level reduction targets against the Carbon Leadership Forum baseline.
Once procurement has happened, users can go back into their projects, and select the actual EPDs for the products used.
Once this has been done, the Selected vs Baseline view allows users to see their realized savings for the project.
This new feature allows any user to import up to 25 PDFs of EPDs at a time, to the EC3 database. The EC3 development team then uses scripts to machine read the EPDs into EC3’s digital format for use in the database. Users can see where their uploaded EPDs are in the process.
The Manage Data feature allows users to view the raw database of EPDs and PCRs and visualize how many EPDs are in the tool, and where they are coming from. Manufacturers can view their EPDs and edit product details like name, plant location and performance information. Program Operators can view their EPDs, and edit the environmental impacts if something was parsed incorrectly.
As stated previously, EC3 relies on user feedback and EPD data to continue to improve and support Building Transparency’s mission of providing the free, open access tools and data necessary to actionably reduce the embodied carbon emissions of construction materials. If you have not registered for the tool, you can do so at www.buildingtransparency.org. The more users we have digging into embodied carbon data and the tool’s functionality, and providing the EC3 team with suggestions for improvements or additional functionality, the better the tool becomes. When it comes to EPD data, asking for EPDs if the first step. There are downloadable EPD request letters on the Building Transparency website. The second step is to use the EPD data and the Project Planner to inform projects and begin, as an industry, to show that reductions are possible and being achieved. This sends a signal to material manufacturers that embodied carbon data and EPDs are a differentiator, and may become a requirement for competing on projects, as well as a business case for further investment in lower carbon materials and processes.
If you have any questions about the EC3 tool or Building Transparency’s other work in the embodied carbon space, please reach out to email@example.com.
 Carbon footprints of materials can be found in the form of a global warming potential (GWP) number in documents called Environmental Product Declarations (EPDs), as a row in tables of information that are comparable to nutrition labels on food items. These tables include the GWP of the material, alongside other environmental impacts with long names and descriptions, like eutrophication and acidification. According to the US Environmental Protection Agency, “GWPs provide a common unit of measure” (kg CO2 equivalent), “which allows analysts to add up emissions estimates of different gases (e.g., to compile a national GHG inventory), and allows policymakers to compare emissions reduction opportunities across sectors and gases.” CO2 has a GWP of 1 since it’s the reference gas being used. Others gases that are included in the GWP are assessed on the energy the emissions of one ton of that gas will absorb over a given time, relative to 1 ton of CO2. The material GWPs are assessed a GWP per unit of material, like tons for steel and cubic yard or meter for concrete.