The Materials Book

214 Imposing Challenges, Disruptive Changes: Rethinking the Floor Slab Philippe Block, Cristián Calvo Barentin, Francesco Ranaudo, Noelle Paulson The United Nations Department of Economic and Social Affairs estimates that by 2050 the world’s population will have increased by over 2.1 billion people. 1 Providing housing and infrastructure for them would require building an amount equivalent to what currently exists. It is simply not possible to continue building the way we do today. Though the field and broader public have been slow to take notice of the building industry’s contribution to the environmental crisis, it is now finally receiving increased attention. Bill and Melinda Gates emphasized the problem succinctly in their foundation’s 2019 annual letter: “The world’s building stock is expected to double by 2060— the equivalent of adding another New York City monthly between now and then. That’s a lot of cement and steel. We need to find a way to make it all without worsening climate change.” 2 To appropriately confront this urgent environmental crisis, the building industry faces three grand challenges: (1) reducing pollution, specifically carbon dioxide emissions; (2) slowing the depletion of natural resources; and (3) minimizing waste production. The challenge of pollution refers first and foremost to embodied emissions, since efforts to reduce this lag behind what has already been achieved to reduce operational emissions. 3 According to the research of Catherine De Wolf, there are two main design approaches that may be applied to achieve the reduction of embodied carbon in a building: (i) build with less