Embodied Carbon / GWP Benchmark Data for Public Buildings?

Hi Misha, We have 14 projects in our embodied carbon database, and except for one that is an Aquarium with a very large water tank for animals, they are all between 16 and 45 kgCO2e/sf (so all below the 500 kgCO2e/m2 that ILFI uses). Of course these only include Structure, Envelope, and a moderate amount of interiors. If you include full interiors, FF+E, Landscape/Hardscape, and MEP we’d probably be around 1,000 for some of our projects. That said, projects with substantial amounts of structural piles, large foundations or small size sometimes have unusually large embodied carbon emissions. -Kjell F

Misha, For what it's worth, I took the CLF database of embodied carbon estimates for about 1000 projects and plotted them up as a histogram--see the attached diagram.  The median was about 398 kg CO2e /m2 (81 lb CO2/sf).  (For the real nerds in the audience, that red curve is fitting the histogram to a Rayleigh Distribution Function, which is a random walk when you don't have a negative value, and fits all kinds of interesting phenonemon including the distribution of wind speeds at a site over the course of the year.)  You can see that there are indeed some projects weighing in at 1000 kg CO2e /m2.   I could imagine that for a small project (say a 1-story project with a hefty foundation and thick concrete slab) that the embodied carbon per unit floor area would be larger than a mid-rise project where that foundation 'hit' is divided over multiple floors.

As part of our 2020 reporting for the AIA 2030 Commitment, we calculated the embodied carbon on a whole slew of projects (28 total) here at EskewDumezRipple, and then sorted them into new construction (16 projects) vs renovation (12 projects).  Those are the green+grey bars on the right of the attached diagram.  The median of our new construction projects matched pretty well the median in the CLF database (67 lbs/sf for structure+envelope+interiors + 10 lbs/sf for MEP).  Renovation projects, of course, kick ass.

Our database is just slightly smaller than Kjell's, with 11 projects.  Ten of them range between 19-50 kg CO2e/sf (214-547 kg CO2e/m2) but we have one outlier as well.  It's an arena that is built on micropiles and is extremely concrete intensive.  It came in well above the 1,000 kg CO2e/m2 mark.  So while it's not the same building type as yours, we had the same experience of needing to pause and really investigate what was going on.  I'm anxious for the industry to develop a wider set of benchmarks for all of us to be able to compare our work against.

Agree with Z’s post. I reviewed about 50 projects from 8 different sources. And we got a median of 250 kg/m2 for small wood frame, about 350 for medium steel/ concrete structures and 650 for carbon intensive projects. The carbon intensive projects ranged from 500 to over 1,200, so 1,000 is on the high end but not out of the question. Larry Strain Sent from my iPhone

Misha, I'll add a few more values to the mix. We have analyzed 17 core/shell and/or core/shell + interiors which run between 10 and 55 kg CO2e/ft2 (~100-600 kg CO2e/m2). Renovations are typically on the low end, new construction on the high end, which matches up with what others say. I also want to add a note to Z's point about the foundation 'hit' - the roof can be a not insignificant 'hit' (though less so compared ton the foundation) when applied to only 1 or 2 floors. Best, Jeremy

Hi Misha, In my experience if you're performing a WB Embodied Carbon calc and including interiors and building services it is not uncommon to get up to 1000kgCO2/m2. RIBA suggest the business as usual WB Embodied Carbon in the UK is between 1200 and 1400kgCO2e/m2 but this includes a scope which is fairly unrealistic to calculate on typical buildings. If you're only including the structure and envelope then 1000kgCO2/m2 is significant but not unheard of.  James