Flipping the Script: From EPD To Community LCA
Recently, I set out on a slightly unconventional project: I took a public Environmental Product Declaration (EPD) for a chair and used it to create a community LCA model in CarbonGraph. The goal? To share a ready-to-use foundation so that anyone wanting to perform an LCA on furniture (or a similar product) can start with a working model rather than a blank canvas.
Why This Matters
1. Accelerating LCA AdoptionLife Cycle Assessment (LCA) is often seen as expensive, time-consuming, and reliant on specialized software. By recreating a group of Community Models from publicly available data, we’re working to give the community a head start. Instead of reinventing the wheel, users can begin their own LCAs from a solid baseline.
2. More Transparency & CollaborationWe’ve all run into the dreaded “black box” problem, where an LCA’s results are shown, but the underlying assumptions and data remain hidden. By sharing models openly, we demystify the process. Teams can see exactly how each piece of data was used and how key parameters (like steel weight or energy use) were defined.
3. A Springboard for Scenario TestingOnce a baseline model exists, you can easily adjust parameters to explore “what if” scenarios. Want to see how lightweighting the product impacts specific environmental dimensions? Need to test different energy inputs or packaging options? By dropping in new data, you can quickly compare scenarios side by side.
The Process in a Nutshell
- Gathering the DataWe started with Kielhauer’s chair EPD (I should mention that this is simply a public EPD and Kielhauer is not affiliated with CarbonGraph), which details various manufacturing inputs and outputs. This gave us an inventory of raw materials (steel, plywood, plastics, packaging), along with specific processes from the EcoInvent database. While we don’t have perfect information on some areas of the product, we’ve got a great starting point.
- Building the GraphUsing CarbonGraph, we mapped out each part of the chair’s lifecycle, from sourcing materials to final assembly. We converted units, added density parameters, and then connected the dots between manufacturing steps, energy use, and transport.
- Parameterizing Key InputsWhere possible, we used parameters to represent variable factors like how much wood goes into the frame, steel into the hardware, and how efficient the manufacturing process is. This makes it easy to pull levers in the model and see how changes ripple through the overall impact.
- Comparing to the EPDOur recreated model was within about 7% of the EPD’s Global Warming Potential value. Perfect alignment isn’t always possible because public EPDs don’t share every assumption or detail. But getting this close validates that our approach (and data) are solid enough to serve as a reliable foundation for others.
- Running ScenariosAfter the baseline calculation, we looked at how changes in energy efficiency or material use affected impacts. CarbonGraph lets you stack multiple changes at once, providing a clear view of the cumulative effect of different design or manufacturing decisions.
What You Can Do With This Model
- Kickstart Your Own LCA: If you’re building a chair, a table, or any similar product, you can adapt this model to match your specific process. You’ll save hours of set-up work.
- Experiment With Design Changes: Want to see if switching to post-consumer recycled steel or changing the plywood supplier reduces impacts? Simply adjust the parameter in the model and rerun the calculations.
- Collaborate and Share: The biggest benefit of a community model is that you can share it with colleagues, other manufacturers, or even customers. It fosters a more open dialogue about environmental performance and trade-offs.
- Educate Stakeholders: If you’re a designer, manufacturer, or sustainability consultant, this model can help you communicate the potential impacts of various decisions to non-technical team members or external stakeholders.
Next Steps
- Explore the Model: Sign up for a free CarbonGraph account (or log in) and visit the Community Models section. Look for the Chair Community model to copy and adjust.
- Share Your Feedback: Found an interesting result or a suggestion for improvement? Let us know! The beauty of community models is that they’re never finished—each project that builds on the last makes for a richer, more informed LCA library.
- Propose a New Model: If there’s a specific product category you’d like to see next, or if you have data from another EPD, we’d love to hear about it.
Final Thoughts
Building this LCA model from a publicly available EPD isn’t just a technical exercise—it’s a move toward greater openness in the LCA community. By replicating someone else’s study, making our assumptions explicit, and inviting others to experiment, we hope to speed up learning and improve the quality of LCA work overall.
Just like the syringe model we shared last time, this new chair model is meant to be a living resource. Use it as a reference, a starting point, or even just a curiosity to see how a real-life LCA unfolds behind the scenes. The more we share, the more we all grow—and that’s got to be good news for anyone aiming to design more sustainable products.
If you're ready to build on this model, check it out: