For many years, the idea of a green building was one that used less energy. Now, as once-fringe elements such as solar panels and double-paned windows have become commonplace and the climate crisis has become widely acknowledged, energy-efficient buildings with low or no carbon emissions are becoming the rule, not the exception.
And rightly so. Buildings are responsible for 74% of electricity consumption and a third of greenhouse gas emissions in the United States alone. But as buildings get more efficient, it’s no longer enough to worry about how much energy a building uses. Today, and in the years ahead, the building industry will need to think about not just a building’s operational emissions but all the energy that goes into creating it—from the harvesting and manufacturing of building materials to the energy used in construction to the energy required to eventually demolish and dispose of construction materials when the building is no longer needed.
This footprint, known as embodied carbon, is estimated to account for 11% of global carbon emissions and 75% of a building’s emissions over its entire lifecycle. For the building industry, reducing embodied carbon is the next big challenge.
That’s the reasoning behind a new campaign aiming to put embodied carbon on the agenda of lawmakers and to start putting an upper limit on how much embodied carbon a building can have. The campaign is an effort of the Architects Climate Action Network, a grassroots industry group founded by a few designers in 2019 that has rapidly grown to include more than 1,000 supporters across the U.K.
“We know now that embodied carbon emissions can account for up to 75% of a building’s total emissions over its whole lifespan,” says ACAN’s Joe Giddings. He says the total embodied carbon emissions of new buildings and infrastructure in the U.K. amounts to 50 million tons of CO2, or more than 10% of national emissions. “There are 149 countries whose entire national carbon footprint is smaller than that of the U.K. construction sector,” he says.
Globally, the problem is enormous. The nonprofit organization Architecture 2030 estimates that new construction creates more than 3.7 billion metric tons of embodied carbon emissions annually, the equivalent of the annual emissions from 950 coal-fired power plants.
“I think there’s a realization definitely in the last two years that construction industry has been too slow to change the way that it works and to change the way that we build, coupled with continuous revelations from climate scientists about how vast the climate emergency is already,” Giddings says.
ACAN’s campaign calls on the U.K. parliament to amend its building and planning rules to require whole lifecycle carbon assessments for building projects and to put an upper limit on how much embodied carbon a project can have. The campaign is currently collecting signatures and asking concerned architects, designers, and builders, along with the general public, to send emails to their elected officials calling for policy change. Though the campaign is U.K.-focused, its aims would be just as relevant in the United States, another major embodied carbon contributor.
And it could work. The young organization has successfully used this approach in the past. In 2020, ACAN called on its supporters to challenge proposed policy changes that would reduce energy efficiency requirements in buildings, leading to more than 3,000 responses arguing against the moves. Giddings says this led to changes in the proposed policy. “We can see that this kind of people power can really make a difference, because we managed to get some concessions on what the government was proposing,” Giddings says.
The group is also calling for change within the architecture industry. They led a campaign against architecture firms taking on airport projects with large carbon footprints while claiming to be focused on sustainability—an effort that resulted in hundreds of paper airplanes being mailed to the office of Foster and Partners, one of the U.K.’s biggest architecture firms and a repeat airport designer.
“We drew a bit of criticism for that because people say well that’s not the big issue, and I can sympathize with that,” Giddings says. “But what we wanted to try to do and what we continue to try to do is start a conversation about what architects do and what we’re involved in when we talk about development. We’re involved in this big economic framework around the world that has devastating consequences.”
The embodied carbon campaign is much more rooted in research, with a detailed report on embodied carbon and construction, and focused on implementing specific policy changes.
There are precedents to follow. The Netherlands has had a policy in place since 2013 requiring an assessment of the environmental impact of materials used in most buildings. And France is set to institute a new policy this year that will require developers to measure and report embodied carbon emissions in order to receive building permits, with the goal of setting limits on embodied carbon in new buildings. In the United States, California instituted a new policy in 2020 that requires embodied carbon declarations for certain building materials used in state building projects.
For now, these policies are incremental steps. Recognizing and accounting for embodied carbon is a beginning, but actually changing practices in the building industry to bring embodied carbon emissions down will be a much bigger effort.
Giddings says now is the time to act, and not just because the climate crisis is out of control. Later this year, the U.K. will be the cohost of COP26, the United Nations Climate Conference. “The U.K. is going to want to be seen as leading, and the construction industry is just one of those tough areas that only a handful of countries have been bold enough to tackle,” he says. “The first win really will just be the government acknowledging the problem. So that’s what we’re focusing on. I think there is an opportunity this year to make some progress.”