SOM Unveils Carbon-Capturing Building at COP26

SOM’s Urban Sequoia is a vision for cities that suck in more carbon emissions than they create. And the practice is launching the proposal with the design of a prototype high-rise that could be built today and, SOM suggests, would be the tallest tree in a ‘forest’ and undergrowth of carbon-capturing buildings and infrastructure. The concept doesn’t suggest one big fix but demonstrates how a number of strategies and emerging technologies – from biomaterials and biomass to carbon-capture technologies – can be optimised and work together and at scale. The use of bio-brick, hempcrete, timber and bio-crete reduce the carbon impact of the concept building’s construction by 50 per cent compared to concrete and steel, says SOM. The building also includes materials and nature-based solutions and technologies that absorb carbon over time. SOM says ultimately the concept building could sequester up to 1,000 tons of carbon a year, equivalent to 48,500 trees. And after 60 years, the building would absorb 400 per cent more back carbon than was emitted during its construction. SOM imagines the building as the hub of a number of virtuous circles and value chains, the focus of a new economy for carbon and biomaterials. Biomass and algae on its façade could turn the building into a source of biofuel that powers heating systems and even cars and aeroplanes. It would also be a source of bioprotein. Captured carbon could also be used in various industrial processes.