A RICS-backed coalition is pushing sustainable construction into a stricter era of measurable performance. CLEAR aims to standardise whole life carbon reporting across the built environment, giving developers, investors and regulators consistent data on embodied carbon, embodied carbon in materials and the carbon footprint of construction. That creates a stronger basis for whole life carbon assessment, lifecycle assessment and life cycle cost decisions, all central to sustainable building design, low carbon design and the delivery of net zero whole life carbon and net zero carbon buildings. Comparable data is making life cycle thinking in construction a commercial requirement, not a niche exercise. Fresh analysis showing £22.1tn of annual value lost through poor resource use is sharpening the case for the circular economy in construction. Reuse tools, design for disassembly and end-of-life reuse in construction are pushing resource efficiency in construction, sustainable material specification, low embodied carbon materials and low carbon construction materials closer to mainstream sustainable design. The UK’s expected acceleration of the Warm Homes Plan shows that decarbonising the built environment depends on mass retrofit of existing homes into energy-efficient buildings and a broader low carbon building stock. The next phase of environmental sustainability in construction will be defined by eco-design for buildings, sustainable building practices and building lifecycle performance, with far greater emphasis on carbon footprint reduction across everyday assets than on isolated showcases of green construction.