Bringing carbon into the first design charrette
A good design balances multiple competing ideas. By grounding sustainability strategy in data instead of vibes, tradeoffs become apparent and clarity on the right approach becomes possible.
Why is carbon hard to balance in a charrette?
In the first design charrette, each discipline sees its own part. The structural engineer knows the frame, the facade consultant knows the curtain wall, the MEP engineer knows the equipment, and the architect is trying to hold all of it alongside cost, program, and the client’s wishes. Without a shared model, every conversation about carbon starts from a different number, or from vibes.
When EHDD launched the first version of our model, the launch post described its job plainly. “EPIC, as an early phase tool, opens conversation within a project.” That conversation is where the tradeoffs get worked out.
What does a shared baseline change?
A shared baseline grounds the conversation in data. The baseline is the project designed to business-as-usual assumptions, and every scenario is measured against it. When the team agrees on the baseline, it can spend its time weighing the tradeoffs between options.
The data also shows where to spend effort. Structure gets attention because it is big and easy to picture, and on many projects the facade, the interiors, or the landscape can matter as much. The question for the team is how to focus effort where it matters most. A breakdown by element answers it, and tells each discipline whether its decisions are the ones that matter most for the project.
How should a team talk about an uncertain number?
Early numbers are ranges, and the team should talk about them that way. At concept most inputs are defaults, and an honest model says so. Unmodified C.Scale results have landed within about 5 to 30 percent of whole building LCA. When two options overlap, the carbon difference between them is small, and the tradeoff can turn on cost, program, or design. When they separate, the team knows the choice matters. Reading results as ranges brings clarity on the right approach without a fight about precision.
Where does the team do this work?
The work happens in the same tools as the design. C.Scale projects can be shared with collaborators, including guests outside the firm. In Autodesk Forma, the embodied carbon analysis C.Scale powers runs inside the massing model, so the hotspots show up while the building is still a set of extrusions. Keith Hempel, president of LPA Design Studios, puts the result simply. “C.Scale gives us the ability to make informed decisions earlier in the design process.”