The 21st-century city is a crucible of innovation and challenge, a complex organism where the imperatives of growth, sustainability, and human welfare perpetually intersect. Today, the Architecture, Engineering, and Construction (AEC) industry—the very skeleton and circulatory system of our urban environments—stands at the precipice of its most profound transformation since the Industrial Revolution.1, 2 The catalyst is Artificial Intelligence (AI), a force not merely of incremental improvement but of paradigmatic shift. As AI reconfigures the processes of designing, building, and maintaining our cities, it presents a powerful duality: it is both a transformative engine for urban development and a potent tool for its own regulation. This duality frames a critical discourse around two intertwined concepts: AI Governance (the rules, ethics, and frameworks for developing and deploying AI) and Governance in AI (the active, operational use of AI systems to enhance the oversight, transparency, and regulation of the AEC sector itself). Navigating this duality is not an academic exercise but a practical imperative to harness AI's potential for urban resilience and equity while erecting robust safeguards against its systemic and malicious risks.