The interlinked crises of climate breakdown, biodiversity loss, and societal inequity are the most serious issues of our time. Buildings and construction play a major part, accounting for nearly 40% of energy-related carbon dioxide (C02) emissions while also having a significant impact on deforestation, habitat destruction, and species extinction. Meeting the needs of our society without breaching the earth's ecological boundaries demands a paradigm shift in our behavior in the building sector. Together with our clients and collaborators, we must design buildings, cities, and infrastructures as indivisible components of a larger, constantly regenerating, and self-sustaining system. The knowledge exists to begin that transformation now, but what has been lacking is collective will. As a sector, we must work together to reshape our approach to architecture and urbanism at the speed and scale the crises demand.