The Materials Book

248 MaGIC: Marginal Gains in Construction John Orr Construction is a ten-trillion-dollar industry; in creating and maintaining our built environment, it underpins economies and worker productivity. Yet despite its importance, construction sector productivity has been flatlining for decades. Practices that have transformed other sectors, including automation and lean principles, have not yet been adopted. Limiting temperature rise to 1.5°C will require an 80 percent cut in greenhouse gas emissions by 2050. This is significant for buildings and construction, as these sectors account for 40 percent of energy- related CO 2 emissions. We also expect to add 2.5 billion people to our cities by 2050 and 230 billion square meters of new floor space by 2060—with just under half of this occurring in countries without mandatory building energy codes. So in parallel to cutting emissions, we must accommodate a growing, and increasingly urban, population. To effectively tackle climate change, historic practices of inefficient overdesign must be reversed. Success in reducing the energy required to operate buildings, and the introduction of strict targets for near-zero-energy buildings in Europe, now means that the energy associated with materials can approach 100 percent of total whole-life energy consumption. The importance of this is highlighted by our analysis, which found that embodied energy savings in the order of 50 percent are possible. The aggregation of small marginal gains that collectively deliver transformations