Bianca Wong, global head of sustainability at Kingspan Group (LSE:KGP), explains how the environmental impact of construction can be reduced by changing regulations, designs and materials.
- The built environment has a huge impact on climate as it is responsible for 39% of energy-related emissions globally.
- Its footprint can be addressed by reducing the embodied carbon of buildings, which encompasses all the CO2 generated across all phases, from design to dismantling.
- Sustainability currently comes at a premium for companies in the construction sector, but it will pay off in the long term.
Embodied carbon encompasses all the CO2 generated to make a building, such as the materials being used, the construction process itself, all the fixtures and fittings inside as well as from deconstructing and disposing of it at the end of its lifetime.
It is estimated from the energy used to extract and transport raw materials as well as emissions from manufacturing processes, usually by surveyors, architects or designers at the design stage and later by researchers and analysts to provide evidence for policymaking.
According to research from Preoptima, a cloud-based software platform for the construction industry, the world could avoid over 10 gigatonnes of CO2 equivalent by 2030 by acting early on embodied carbon emissions, as opposed to the business-as-usual approach of late-stage analysis. To calculate this, it used floor area estimates from the International Energy Agency (IEA) that over 40 billion square metres of new floor area will be erected globally by 2030.
Conversely, without action, embodied carbon could add up to 50 gigatonnes of CO2 equivalent by the end of the decade. Indeed, the built environment is responsible for 39% of energy-related emissions – 28% comes from the operational energy used to heat and light them, while the other 11% is generated by the materials and the construction phase.
According to Wong, as we start to power buildings with cleaner energy and improve their efficiency, the 28% will come down, but embodied carbon will become a bigger proportion of the equation if it is not addressed.
Supply chain woes
The built environment comes with an extremely complex supply chain, especially as many developments are bespoke. There can be repeat design for institutional projects such as schools and offices, but designs are mostly a one-off with hundreds if not thousands of people involved – from the architects to the consultants and contractors.
Materials are supplied by a huge range of companies, from primary and secondary structure to the tertiary, external facade of the building, plus all of the internal finishes. As such, trying to get everybody on the same page can be challenging, with sustainability concerns adding a whole new layer of complexity.
“I don’t envy people who are in charge of procurement of construction projects, because there’s just so many different items that they have to account for, and then also to understand the impact of each of those items,” says Wong. “Is it very necessary for the design, or is there a better solution to reduce the overall impact of the building moving forward? I think that’s where things can become very tricky.”
Equally, these considerations need to happen at the design stage, which needs to factor in the long-term impact of the building and how to best reduce it at the construction phase, instead of relying on refurbishments in the future.
“There has been a bit of a step change in the last one to two years in terms of people understanding the overall issue,” Wong explains. “People are mobilising together to try and do something about it and then trying to work towards bringing it into regulation as well and changing the way that we actually design buildings.”
Addressing embodied carbon
According to Wong, regulations are key in reducing the carbon footprint of the built environment. The authorities should impose sustainable designs for new buildings and retrofits for the existing ones as part of country or city climate goals.
In the EU, legislation has mostly focused on cutting greenhouse gas emissions associated with energy consumption, although embodied carbon is increasingly becoming a priority. Only five EU countries – Denmark, Finland, France, the Netherlands, and Sweden – have introduced regulation on whole-life carbon emissions, addressing both operational and embodied emissions.
This is driving better design, which includes optimising natural resources such as natural daylight, ventilation and energy. This not only reduces the operational carbon, but also the amount of materials being used – if a building has natural ventilation, it will not need a mechanical system for it.
Indeed, the architectural community is pushing manufacturers such as Kinsgpan to provide the information around embodied carbon, says Wong.
Some practical solutions
So, how do you make a building with low embodied carbon? According to Wong, it all starts at the design stage, with architects actively considering the impact of the different materials being chosen. This includes optimising natural resources such as light and solar energy, as well as boosting energy efficiency by making sure that the building is airtight.
To achieve this, Kingspan has been working with its own suppliers, which has led to the launch of a new range of insulated panels with 41% less embodied carbon compared to previous models. It has also invested in H2 Green Steel, which intends to produce steel with 95% less carbon content.
“That’s the kind of approach we’re taking with our suppliers: we’re talking to them about what we want to achieve, what we feel our customers are going to want moving forward, and ultimately trying to work collaboratively together to make that happen so we can bring lower embodied carbon solutions to market,” adds Wong.
“It’s not easy, and a lot of them aren’t on the sustainability journey or at the rapid trajectory that we are, but ultimately we need to address the emissions from the embodied carbon of materials that are made within buildings, and also then to be able to recirculate those materials ideally in a future state. It’s going to be very important to stop extracting materials from the earth.”
The future is circular
Ensuring that materials are circular will further reduce a building’s embodied carbon, as they will be reused instead of turning into waste. Wrecking ball demolition means that everything will be sent to landfill, with new developments using raw materials, which will require more resources and energy. Many product regulations, however, still require companies to use virgin materials in some cases, so they need to be updated.
“The way we think about the circular economy is that we have a product lifecycle framework and we are trying to embed circularity principles at each stage,” Wong explains.
“In design, we’re looking at: can we make the same high performance products but with less raw materials? Can we use materials that are from a recycled or a bio-based source but still maintain that same high level of performance factory processes? How can we eliminate actual waste creation so we’re not wasting any materials, or can we reincorporate that back into the manufacturing process? Then it’s extended life and reuse: can you extend the benefit of that product as long as possible?”
Recycling should be the second-last resort (before landfilling), only if the product cannot be reused in its current state. As such, the assembly and deconstruction of a building need to be factored into the initial phase of design.
What’s in it for sustainable companies?
Currently, these processes are not convenient from an economic standpoint, Wong admits, and many materials are not available yet at scale. There is no inherent value in waste, so using virgin materials remains the easiest option. As such, putting effort in the short term might seem counterproductive, but it will pay off in the long term.
“It’s not sustainable in the long run to continue with a linear approach, particularly if we want to keep global temperature rise of above 1.5°C. We do feel that it’s going to become more important to our customers as well, you know, higher levels of recycled content and materials. And for us to support them in terms of take back schemes and maybe leasing models, that kind of thing in the future,” Wong concludes.
“Very similar to what we see around wanting to build buildings in a more sustainable manner, we also feel that circularity will be a big part of that as well. We see them as two very parallel topics that need to be addressed together, but sometimes they overlap and sometimes they don’t, it depends on the specific requirements of projects and customers. But ultimately, we feel that it’s going to be a big topic that needs to be addressed.”