The contribution of buildings to climate change has become widely acknowledged. On 3 December 2015, the United Nations Environment Programme (UNEP) held the first ‘buildings day’ at COP 21 (the UN Climate Change Conference) devoted to the decarbonization of the building stock. There are several forms of negative contributions that buildings make to climate change, but high on the list are embodied and operational energy demands, which largely depend on fossil fuels and result in greenhouse gas emissions. Given the urgency of the risks associated with climate change, the mandate to contain global warming to 1.5–2.0°C and the urgency to reduce energy demand and decarbonize radically, a key challenge is what actions can be taken across a whole suite of areas relating to the building stock. Over the past 18 years, there have been several Building Research & Information special issues exploring this theme in terms of technical, social, environmental and economic aspects as well as numerous papers in regular issues.