Pie charts and other types of data visualization help make potentially difficult or confusing conversations about embodied carbon in building design much easier. iStock photo
With new regulations like Boston’s Net Zero Carbon Zoning Proposal for new construction and the accelerated emissions limits set by BERDO, there is a new urgency for the design community to not only find low-carbon solutions for existing buildings but also translate the implications of those decisions for building owners and the public in ways that are both compelling and actionable.
The tallest hurdle for design firms to tackle embodied carbon is to first start measuring. The fun begins after that with analyzing colorful pie charts and graphs! Architects tend to love diagrams after all.
Building nothing or building less, is the best way to reduce or, more importantly, avoid carbon emissions. But if you must build new, let’s talk pie – specifically pie charts and how to use them for owner engagement, carbon avoidance and making an impact where it matters most.
Hotspot Comparisons
Software such as Tally LCA is used to conduct whole-building life cycle assessments and will auto-generate a few comparison graphs to illustrate the global warming potential of building materials as a percentage of the project’s total carbon. It is a useful starting point to highlight hotspots at a high level.
Take one recent Finegold Alexander project illustrated in the graph here: No one building material had significantly higher emissions than the others, but organized by component type, the data starts to highlight carbon hotspots in the wall and floor assemblies.
Wall assemblies here were responsible for more than 50 percent of the embodied carbon. By utilizing the raw Tally data in Excel, the project took a deeper dive into the carbon breakdown of the specific wall materials.
The three largest carbon contributors in the walls were painted gypsum board, masonry and insulation. This analysis provided the design team with a direction to focus their research on low-carbon CMU, different facade systems and greener insulation.
In a recent Finegold Alexander project, pie charts helped identify an easy and inexpensive way to create a greener project. Image courtesy of Finegold Alexander Architects
These lower-carbon swaps do not always mean a cost increase. The low-hanging fruit on this project was the acoustic insulation in interior partitions. It was a simple swap to use wood fiber insulation rather than mineral wool, and given the high number of acoustic partitions in this particular design, that one change made a significant difference.
The power of the pie chart lies in highlighting anomalies and hot spots and targeting efforts. It is an excellent tool for comparing data to projects, but other graphics can illustrate the broader impact, which leads us to bar charts.
Make it Relatable
Stacked bar charts are a useful visualization tool to transition from comparative pie charts to actual carbon quantities.
These are particularly helpful when comparing against a baseline. For green building certifications or zoning code requirements, a percent reduction from baseline is mandated.
That requires analysis of two separate models: One with business-as-usual construction materials and one with the proposed lower-carbon design. Stacked bar charts can show the holistic impact of design decisions with real values of CO2.
While pie charts and bar charts are useful for highlighting hotspots and showcasing improvement, the data is not always digestible to building owners.
What does 40,000 kilograms of CO2 really mean? What is the real-life impact of selecting a certain structural system over another, or paying a 5 percent cost increase for lower-carbon concrete?
Megan Brown
To understand this, make the data relatable.
That’s where visual comparisons come in – translating carbon quantities into more familiar terms: number of gas-powered cars, home energy use, or trees planted. These reframes ground abstract metrics in real-life impact.
If we can do anything to demystify embodied carbon, promote avoidance and celebrate the small victories, we’re moving the needle. Similar to Boston, Cambridge and Newton are also advancing embodied carbon standards of their own and momentum is building across the region.
Keep the momentum going and we hope to see embodied carbon language embedded in more codes, incentive programs and conversations in general. We need more pie [charts] and diagrams!
Megan Brown is an associate at Finegold Alexander Architects.
