How to set carbon targets at concept design
Goals give structure to decisions and help teams evaluate tradeoffs. Early goals are guides toward a better project, before things get lost in the weeds.
What happens when goals come late?
Most projects start with an ambition. The client wants a low-carbon building, or the firm has a climate commitment, or a city requires a number. If the team first measures carbon in design development, deep in the weeds, the ambition meets a design that is already set. The team can document the result, swap a few products, and buy offsets to close the gap.
What does an early goal do?
An early goal gives structure to design decisions. At concept the goal can still decide whether to reuse the building, how much to build, and which systems to use. The team can write a baseline, set a target against it, and weigh the tradeoffs between schemes against the target the same way it weighs budget and program. C.Scale is built for that moment. You can set targets before there’s BIM and test material choices while they’re still open.
What did that look like on the AIA headquarters?
When EHDD competed to renovate the AIA’s national headquarters, our team modeled the building’s whole life carbon to 2050 in the proposal and showed the client three paths. Energy efficiency alone left operational emissions climbing to about 18,000 tCO₂e. Clean electrification with 170 kW of rooftop solar held net emissions near 5,000 tCO₂e. Adding local carbon offsets brought the project to net zero by 2040.
With the paths on the table from the proposal, the AIA could weigh carbon as one tradeoff among everything it wanted from the building. It chose to offset the renovation’s embodied carbon by paying for solar arrays on local affordable housing, a decision that works because embodied and operational carbon were counted together over the life of the building.
Why do goals need the whole life?
The big early moves change embodied and operational carbon at the same time. Glazing changes the facade’s materials and the building’s energy use. More insulation adds material and cuts heating. Electrification removes gas combustion and adds refrigerant. A goal that covers only one side can push the team toward a move that makes the project worse overall. C.Scale models both sides together over 30 or 60 years, including refrigerant leakage and upstream methane, so an ambitious target is tested against the whole picture.
What does a team need to start?
All it takes to do a preliminary assessment in C.Scale is ten minutes and a curious attitude. You can generate preliminary data immediately and start asking questions about how to improve the design and set actionable goals.