Barcelona’s push to scale affordable low carbon housing marks a turning point for sustainable construction, where sustainable building design is judged by delivery, whole life carbon, life cycle cost and the capacity to provide net zero carbon buildings that people can afford. The market is focusing on whole life carbon assessment, embodied carbon, embodied carbon in materials and low carbon design, with eco-design for buildings, sustainable design, lifecycle assessment and circular economy in construction shaping environmental sustainability in construction. At Tameside General Hospital, a £14m heat-pump retrofit expected to cut emissions by 2,000 tonnes a year shows that decarbonising the built environment now depends on energy-efficient buildings, electrified operations and strong building lifecycle performance. Approval of the Springwell solar project in Lincolnshire, billed as the UK’s largest solar scheme, connects housing, retrofit and green infrastructure in a financeable model for low carbon building, net zero whole life carbon and a lower carbon footprint of construction, driving carbon footprint reduction across sustainable urban development.