Materials Specifications to Reduce EC - what are you doing?

Good morning, again, CLF Structures forum!

As we seek to reduce the EC content of our buildings and structures, one of the target areas that structural engineers must work with the whole design team to address is that of materials specifications. There is much we can do to leverage the way we specify materials sourcing, refining, and manufacturing to make a big impact. This, of course, requires ‘buy-in’ from other members of the process - manufacturers, contractors, and Owners among others.

How are you specifying your materials to reduce carbon content? Are you, for instance, requiring steel from EAF’s as opposed to, say, Blast Furnaces. What about SCM’s in grout for CMU?

Are you finding the supply chain and other design and construction team members are responsive? What challenges have you encountered in changing your specifications and/or making them more stringent?

The first step towards reduction is measurement, so short of getting material reductions (more optimized spans to reduce total material, specify maximum cement content for concrete, hot-rolled steel from EAFs rather than HSS’s from BOFs, FSC certified wood), structural engineers can track material quantities and ask for product-specific EPDs of the structural materials.

EPDs: Even if the material supplier is unable to produce an EPD, it’s at least worth bringing up. I’m currently in a policy-focused role where I’m talking to suppliers about EPDs and they’re hesitant about the importance of EPDs because nobody’s asking for them! Structural engineers can ask for EPDs in their specs, and if they can’t be produced then ask for a letter explicitly saying they cannot produce an EPD. Gotta start the conversation somewhere

Quantities: If you’re tracking quantities, you’re a hop, skip, and a jump away from an LCA. But with just quantities you can get (rough) embodied carbon assessments with something like SE 2050’s ECOM tool. This is often more internally focused, but it’s a great step in the right direction.