On the route to a carbon neutral world, construction can’t be bypassed.
Knowing that, we have to go down the rabbit hole to find the drivers of CO2 emissions and identify ways to avoid these emissions. Spoiler alert: it’s not as easy as plugging out conventionally generated electricity and plugging in renewables.
1/ Yonsei University conducted a study in which they measured CO2 emissions during the construction phase of a building. According to their research, 2.4% of CO2 resulted from material transportation while 4.2% of CO2 was produced during on-site construction. However, the majority of emissions — 93.4% — was coming from the production of building materials used to build.
2/ Ergo: Optimizing supply chains and operations on-site is advisable from an economic point of view. But: it doesn’t move the needle on emissions. The main lever to reduce emissions in the construction industry are building materials.
3/ And: Within the subset of building materials, steel, cement, and other mineral materials have the largest impact, making up more than 50% of the CO2 emissions in the construction industry
The impact becomes even more tangible when looking at absolute numbers: the production of one ton of steel emits ~1.8 tons of CO2 while the production of one ton of cement releases ~0.58 tons of CO2. And: in 2018 ~4bn tonnes of cement and ~900mn tonnes of steel were used in the construction industry.
4/ And: There are 3 ways to cut down these emissions:
5/ Ergo: When assuming that we can’t scale down the use of cement and steel to zero, we have to find ways to decarbonize their production processes.
6/ And: Both production processes have similar key characteristics.
7/ And: These key characteristics make it particularly difficult to decarbonize the production processes.
8/ Ergo: Decarbonizing the production of building materials is highly challenging but technically achievable through a combination of different solutions.
9/ But: the most promising solutions (such as CCS or the use of hydrogen) are currently in pilot stage and not available at industrial scale.
10/ Ergo: Turning today’s building materials carbon neutral isn’t a plug & play game. It’s a complex challenge that forces us to think of more than just a carbon neutral version of what we do today. We have to rethink use-case specific choices of building materials and ways to use materials more efficiently than we currently do.
The good part of this is that we already have one or two ideas on how we can make it work. → stay tuned for Foundamental’s next article.