Advancing Sustainability in Buildings through the Water–Energy–Quality Nexus

In the United States, over 125 million buildings make up a complex and resource-intensive built environment, particularly in rapidly urbanizing regions. These buildings are major consumers of both water and energy, and their operations significantly influence water quality within internal systems such as premise plumbing and cooling towers. Understanding these interconnections is critical because efforts to conserve energy and water can unintentionally compromise water quality and public health. This state-of-the-art review synthesizes research and technological advances from the last 15 years (2010–2025) at the intersection of water, energy, and water quality (WEQ) in buildings. As the interactions among these domains grow increasingly interdependent, a systems-level approach to the WEQ Nexus is essential to achieving sustainable, resilient, and health-protective building environments. This paper identifies key sustainability challenges, regulatory gaps, and emerging strategies, and outlines future research and policy directions to support integrated WEQ management in buildings.