Carbon Expert of the Month, November 2021
Judhajit (Jude) Chakraborty
Jude is a Senior Sustainability Consultant/ Associate at design and engineering giant Stantec.
Stantec provides professional consulting services in planning, engineering, architecture, interior design, landscape architecture, surveying, environmental sciences, project management, and project economics for infrastructure and facilities projects.
Watch the full interview
“We need to be more proactive in educating our clients and our peers and everyone in our industry. This cannot be tackled singularly by sustainability professionals. It’s a global movement; we are all in it.”
What led you to become a construction carbon expert?
I am trained as an architect in India for my undergraduate degree. The architectural education in India is very deeply embedded in sustainability and bioclimatic design and how those can be applied to the active and passive strategies in buildings. Till now, we looked at sustainability as a measure of energy performance or how we can design the building so that it consumes less energy. That was the story until recently.
It took us very long to understand that it’s the carbon dioxide or the CO2 emissions or the greenhouse gas emissions that holds the metric forearth’s stability. And buildings contribute to about 40% of greenhouse gas emissions. I think that was the pivotal moment which led me to think deeply about carbon and working to low carbon designs, both embodied and operational. I still remember May 9th 2013 which was the day when earth’s CO2 concentration first crossed 400ppm. That was another significant moment as well.
What is the current focus of your role?
I am an integral part of Stantec’s sustainability service line. We call it the Carbon Impact group. My role in the team has been to lead and grow the holistic part of the services that we offer. That includes the embodied carbon analysis, circular economy in design and certifications . We are also looking into doing triple bottom line analysis, a cost benefit analysis of different sustainability strategies that comes into play in projects.
I also work with our high-performance design and analytics team, because that’s how I started my sustainability journey, doing analytics. Usually our team gets involved pretty early in the design process, which should be the way.
In terms of projects, Stantec takes pride in providing design solutions in a wide array of project types, be it healthcare, commercial offices, hotels, transportation, science and technology, aviation facilities, affordable housing, master planning, et cetera, You name it and we probably do it.
Which projects and achievements are you the proudest of?
It’s a project with the University of California (UCSF) in San Francisco. We are fortunate enough to work with UCSF on one of their new clinic buildings. It’s a five storey-tall clinic of about 20,000 square meter. Embodied carbon was not looked at in the first place. So Stantec came in and we gave presentations about embodied carbon and how important it is and how UCSF can set a benchmark for other projects to follow suit.
That project was a concrete-heavy building, the design and the project costing was more or less done when we started looking into embodied carbon. But UCSF was also very progressive in terms of that they wanted to try low carbon concrete and see what implications and environmental impact it creates.
We looked into low carbon concrete. We started to talk to structural engineers and with the concrete company and we got to work with them very closely. We got to know what is important in terms of structure, and in terms of looks, because there has to be a balance between the environmental impact and the durability, the strength of the building, and aesthetics.
We looked into from increasing the fly ash content, to increasing the SCMs (the Supplementary Cementitious Materials), to reducing the water to cementitious materials ratio, in other words, the W/CM ratio. The concrete rep then made custom EPDs for those different types of concrete mixes. There were five different types of concrete mixes depending on their strengths that were used in that project. And we looked into each one of them. We also tried to see methods and ways to inject recycled CO2, to sequester carbon in the concrete.
All these things went on in the background, while in the foreground, we were doing the LCA analysis. With just the concrete, the project was saving around 33% on embodied carbon from the baseline to the proposed whole building design. We also looked very carefully into thebaseline design and questioned, “What is the regular design, what is the regular mix?” And so we looked into the various standard mix types, looked into their EPDs which helped in creating a baseline which was not vague. In the end, it was a very good study which our clients UCSF liked and hopefully this will set a precedent for other projects to follow.
“Don’t shy away from talking about embodied carbon.”
How does One Click LCA help you achieve your goals?
One Click LCA has been like a godsend to us with all the different types of databases and the graphic quality.
As architects, we like to see things visually: all the material flows, all the LCA stages and how the material flows inform the different life cycle stages. Those graphics are pretty amazing in One Click LCA.
The One Click LCA database was another big plus point, which not only had the TRACI database for the US centric projects, but also you had the EcoInvent, the Gabi, all the other databases that you use in Europe and other parts of the world. So that was a big plus, because we work globally on many different kinds of projects.
Of late, we are working on a lot of projects in the UK that require the GLA mandate to do LCA. So that has a different methodology as well. In the US or for LEED, you don’t have to consider the MEP (Mechanical Electrical Plumbing), the site impacts, or the interiors. But as per the GLA, the Greater London Authority, LCA mandate, you have to include everything in your LCA calculations. So when we spoke with One Click LCA and found that it already has developed that module, that was a huge help. It’s still developing, and continuous development is the way to go. But, just having that module to plug in the numbers, to have all the information that GLA requires us to put in, in itself is a huge improvement.
Lastly, have to mention about the Carbon Designer tool. That’s amazing. We can look into options in reducing carbon very early on in the design process when we don’t even know what the material profile would look like. So all these features makes it very handy and useful.
About ‘Carbon Expert of the Month’
Carbon Expert of the Month is One Click LCA’s way to showcase the expertise, inspiration and best practices of One Click LCA users. Each month, we feature experts who are passionate about reducing carbon in general and from materials in particular, who seek to push projects beyond the boundaries of common practice, and who wish to share from their personal experience.