After several years of phasing in Buy Clean California, the GWP limits that will come into effect on July 1 2021 have been published! These limits are for:
I am new to the legislation aspect of embodied carbon! Is there a reason why concrete mix designs are not included in this Act?
Hi Alexis. Originally cement was targetted for inclusion, but industry pushed back making the argument that the product is ātrade-exposedā meaning that purchasers could easily change to buying lower-carbon imported cement only and the local California-based cement industry could collapse. The validity of the argument, and if itās applicable to other included materials too, can be challenged. However, their argument won the day and it was excluded from this initial version of the Act. The state has said that they intend to expand the list of eligible materials covered in the future, which would presumably include cement in the future.
Note that Portland, Oregon has a Low Carbon Concrete procurement policy which is effectively Buy Clean only for concrete.
Ryan, I appreciate the response. And thank you for pointing me to the Portland requirements.
Hopefully the cement / concrete suppliers will be more open in the future and evolve mix designs alongside engineers.
Great question on Concrete! In addition to the Portland policy that Ryan shared, I would also mention the Low Carbon Concrete Project - County of Marin and the new bill HB 1103 introduced in Washington State Legislature, which includes concrete, steel, and wood. Similar bills are being considered in other states as well - check out our new map to track!
Iām reading the notes and it seems they took industry averages and then added 15-35% to set an upper limit. So this is aimed at excluding worst performers. I suppose itās a first step but doesnāt seem like it will push things a lot. Do you know if it will be reassessed as the industry average changes?
In terms of updating, the current legislation requires that Beginning on January 1, 2024, and every three years thereafter, DGS will review the maximum acceptable GWP for each material and may adjust the limit downward to reflect industry improvements."
The legislation also prohibits the limits from moving upward if the average gets worse (letās hope not!!) but there is no required trajectory to lower the limits towards net-zero.
The FAQ section in the same DGS page where these limits were published is great! Answer to lots of questions like this: Buy Clean California Act
Question: why mineral wool? Why not XPS, for instance?
Has anyone experienced push back from steel suppliers that they canāt meet GWP limits specifically for HR sections? We have started to put GWP limits on our general notes and in our specifications based off of median CLF baseline values (1.16) and the suppliers are saying that they canāt meet that and average around 1.25. Note, the project is in CA but does not fall under the BCCA.
Our thinking is that if we want to see a change in the materials we have to request/go after more aggressive GWP targets. However, when suppliers are coming back to us and saying itās not possible/ very difficult to achieve and thus left wondering was the data and/or the low/median/high values appropriate in the first place ?
Furthermore, when we are looking at a baseline we are trying to hone in on an appropriate steel EPD to use that has a GWP of around 1.7 (high per CLF). Does anyone have an EPD they can share? I am using OneClick LCA and canāt seem to find one in their database. Itās either too high at 2.11 or too low at 1.36.
@zoe.kaufman I was thinking the same thing. Mineral has such a terrible carbon footprint. They have done an excellent job marketing it as a āgreenā product.
Did you try EC3? These are the results I get by looking up Structural Steel HR sections, with USA as a location (no results when I try California). The results are in kg/lbs but seem consistent with the CLF baseline, with options both better and worse than the baseline value you give (assuming your unit is in kg CO2eq/kg steel).
Iām not a steel specialist so I wouldnāt know if the products described in these EPDs are applicable to your situation.
My apologies for resurrecting an old comment - the topic came through as a recent one due to the replies below and I was reading through what was already said. I think thereās an opportunity to clarify some things here, and also to offer some new information on this aspect of Buy Clean in California.
There were a handful of reasons that cement and concrete were removed from the original Buy Clean act:
Some more recent developments:
Question for both you and @zoe.kaufman - Can you go into this comment on mineral wool vs XPS? My understanding was that even the next gen XPS like foamular ngx had higher impacts than a similar rockwool product. Ec3 has mineral wool maxed out at 0.6691 kgco2e per 1ft^2, and which only a few of the XPS options meet or exceed.
Looking at EC3ā¦ Iām seeing:
XPS:
Polyiso:
EPS:
Mineral Wool:
If we go back to the original comment/post and look at the requirement for Mineral Wool Board (9.79 kgCO2e/m2 @ RSI-1), this value is NOT aggressive at all if you expand it to all rigid insulation types. It would really only exclude HFC blown XPS/Spray foam products.
That said, if you are comparing XPS vs Mineral Wool, the best rigid mineral wool product out there has similar carbon performance to the best XPS product out there, while EPS and Polyiso are about 2-3x less carbon intensive.
Does anyone know how does this limits work if I am using other product that is not Mineral wool? would I measure my insulation against 400kgCo2eq req?
