To limit carbon output going forward, most climate models agree that we need to create more of a circular economy, particularly in the building sector. But how do you do it an industry as inherently materials- and energy-intensive as construction?
Experts speaking on Dec. 5 at a panel discussion at the COP28 climate summit in Dubai pointed to two ways in which the industry is already improving its environmental performance: first, by renovating more, and second, by using building materials with more recycled content.
Panelists speaking in the Buildings Pavilion of the Global Alliance for Buildings and Construction said that renovations are becoming more popular.
For example, U.S. architects billed more last year for renovations than for new projects, according to Lori Ferriss, a senior fellow at Architecture 2030, an NGO established in 2002 to encourage the reduction of CO2 emissions and the building of sustainable buildings.
The choice matters because not-building tends to be an eco-friendly choice than even the most efficient new building. Ferris estimated that for one project she worked on, the reuse and retrofit of a single building, she avoided carbon emissions of about 4 million kg (4,409 tons).
The 10 Percent Solution
Despite such advantages, fewer than 1 percent of all the building projects in the world are renovations. Globally, Ferriss noted, the most recent Intergovernmental Panel on Climate Change estimated that to meet climate targets, this number needs to rise to 5 or 10 percent of the total.
Several panelists noted initiatives that their firms were undertaking to encourage more climate-savvy decisions. For example, Eva Hinkers, Europe Region Chair and member of the management board of Arup, the global design and engineering firm, pointed to a circular building benchmark that her firm had developed in collaboration with the Ellen MacArthur Foundation.
Based on a detailed analysis of carbon measurements in 1,400 buildings, the new toolkit makes it much easier for builders to make better decisions about their carbon use, according to Hinkers. “Because without knowing what your carbon in the building is, and being able to compare the different building options, how do you know what good looks like?” she asked.
Architecture 2030 has also introduced software to make building decisions easier. The agency’s CARE Tool, a carbon retrofit estimator, which makes it much easier to decide whether to build or renovate. Ferriss said that retrofitting the buildings on one small liberal arts campus rather than building new buildings could keep the college from adding 115 million kg (126,766 tons) of carbon dioxide to the atmosphere between now and 2037. “To put that into perspective, if they planted a forest over their entire 100-acre (40.5 ha) arboretum campus, that forest would have to grow for more than 1,300 years to draw down that amount of carbon dioxide,” she said.
Reducing Renovation Risk
However, although panelists agreed that the tools are getting better and clients are more enthusiastic, policies need to be changed to encourage more renovation. One key: better building codes. “One of the challenges we see in reusing buildings and materials is that they aren’t often governed by the same codes and standards that we have for new construction, and so there’s a certain element of risk for building owners in some jurisdictions,” Ferriss said.
Once recovered materials can be tested, analyzed, and certified, Ferriss said, renovations will be easier. “I think this will really de-risk the whole process and enable an acceleration of circularity, both at the materials and building scale,” she said.
Panelists also noted that regulators can also encourage renovation by raising landfill fees for demolished materials. Ferriss said that laws in Vancouver, Washington, and Pittsburgh have shown that this approach can have a positive impact in encouraging more reuse.
Ultimately, panelists agree that designing building in a circular economy is going to require an entirely new way of looking at construction and remodeling. “It’s a very different mindset to designing buildings than we’re used to,” Hinkers said. “It’s not just making it more efficient—it’s really a completely new approach.”
