The recent adoption of the term additive manufacturing (AM) to describe a broad range of digital ‘layer by layer’ fabrication techniques comes 20 years since its inception and more than 10 years since architectural practices engaged with the technology for making prototypes and models. Soon this technology will join existing CNC subtractive and formative processes within the volume and mass-market sectors, where design complexity and increased functionality result in competitive advantage. It is also about a decade since researchers proposed additive manufacturing for construction. Rupert Soar and David Andreen introduce here the different construction-scale additive manufacturing systems currently in development. If linked to physiomimetic computational design strategies, these technologies provide novel possibilities for addressing architecture's manufacturing challenges in the face of energy expenditure, material resources and environmental impact. Copyright © 2012 John Wiley & Sons, Ltd.