Sasaki’s Carbon Conscience App: Assessing Carbon Impact Early and at Multiple Scales
Interdisciplinary design firm Sasaki has introduced the Carbon Conscience App to help designers assess carbon-related impacts from the early stages of planning and encourage them to think holistically about carbon in their projects. Most standard carbon assessment tools available to designers are appropriate for projects already in advanced design stages. After reviewing several internal projects, Sasaki found that key decisions early in the master planning process have significant impacts on the embodied carbon of a project. The creators of the Carbon Conscience App felt that helping designers be critical of architectural and landscape land use decisions by revealing how early decisions can affect embodied carbon was essential, so they developed a tool to support designers in cultivating a “carbon conscience.”
The Carbon Conscience App informs preliminary planning decisions at an urban design scale by giving designers an early-stage understanding of carbon on their sites. Designers can test initial ideas by sketching on a digital interface, receiving feedback on how carbon emissions change as they sketch using an intuitive drawing format. While the Carbon Conscience App operates in a similar way to other carbon calculators, it is differentiated by the fact that it makes estimates of carbon impacts per given land use instead of relying on precise takeoff measurements for different materials. The tool is recommended for campus or neighborhood masterplan scale, but it has enough specificity for site-scale concept design, allowing it to be used for rapid iteration and testing of early concepts. To limit the scope of the app, the developers decided to focus “exclusively on embodied carbon costs, carbon sequestration at maturity, and carbon stored per land use area, rather than considering the myriad decisions that would influence a project’s operations energy usage and carbon cost.” The decision was made to focus on upfront (embodied) carbon considerations of projects, which have been relatively overlooked until the last decade even though embodied carbon often accounts for approximately half of the total operational carbon costs of a project over the course of its lifetime. At the same time, it is important to consider embodied and operational carbon as uncoupled, as a project can have net zero operational emissions while having high embodied carbon, and vice versa.
After creating a free account in the app, users first create a land use field and designate its area, land use type, and cost per square meter. They then describe each land use field by adding multiple material components from a pre-populated list. The material components include: 1) existing vegetation or materials to remain on site; 2) demolition and preparation activities including removal of vegetation and/or existing hardscape and its reuse; 3) addition of hardscape elements including paving, decking, and fencing; and 4) addition of softscape including reforestation, cultivated gardens, turf, and average tree cover. Users can specify details related to each component; for example, the type of turf used, the percentage of tree cover, or whether specific restored ecosystem typologies are present. Users can also add architectural land uses though specifying building program, structural system type, and envelope type, and they can define floors above and below ground as multipliers.
After creating and adding details for all land uses, users are directed to the painting tool to draw on a map, which populates the footprint area for each land use type. After drawing an area for each land use, the app offers estimates of embodied carbon, carbon sequestered, and carbon stored. The app provides low and high estimates for different land uses and material components to account for the variability of materials selection and other design elements—for instance, a designer could choose either a conventional concrete or a more sustainable option that has high amounts of cement substitutes like fly ash.
The development of the Carbon Conscience App was supported by an internal Sasaki research grant. The developers began their process by conducting a literature review, testing existing tools, and compiling peer-reviewed data sets related to carbon emissions, storage, and sequestration. Then they created a database of land uses and projected embodied carbon per unit area of land to compare multiple project types and design approaches. The team brought together embodied carbon, carbon sequestered, and carbon stored to encompass all key carbon impacts associated with construction in a way that previous tools specifically for landscape architects have not achieved—with the exception of Pathfinder, which accounts for carbon sequestration for living materials.
Read more about the Carbon Conscience App’s development in the creators’ white paper, and view Sasaki’s video about how to use the tool here. The new beta version of the tool is now live for designers to use, including an export function to extract graphics for presentations.
One of the Carbon Conscience App’s developers, Christopher Roth Hardy, Senior Associate at Sasaki, was named a 2022-2023 LAF Fellow to build upon previous research to further vet and refine existing tools to enable the design industry to make better decisions regarding carbon.