ACAN is a network of individuals within architecture and related built environment professions taking action to address the twin crises of climate and ecological breakdown. We are in a state of climate and ecological emergency. There is a compelling body of scientific work indicating our present trajectory will lead to catastrophe if we do not make ambitious and radical changes as a matter of urgency. We also acknowledge that the construction industry and the existing built environment are major contributing factors to the crises and as such both require complete and rapid transformation. In the UK, the built environment as a whole is responsible for 42% of national emissions. The manner in which we produce, operate and renew our built environment continues to curtail biodiversity, pollute ecosystems and encourage unsustainable lifestyles. This state of emergency calls for a new kind of professionalism. We can no longer remain secluded within our personal and professional silos. Instead we are harnessing our collective agency; as citizens with a shared professional background and a common goal, mobilising to bring about necessary changes to our industry. We welcome anyone that shares in this vision for change