In 2010, a coalition of major U.S. health systems formed the Healthier Hospitals Initiative. Their aim was to improve sustainability and safety across the healthcare sector. Today, thousands of other health systems and hospitals have joined the effort by implementing sustainable operating practices, greening their supply chain, reducing their waste footprint, increasing their resiliency in the face of weather events driven by climate change, and pursuing sustainable building design and decarbonization. Despite this progress, many health systems lag in combining environmentally sustainable building design with what's known as "well building design" to create buildings that harm neither person or the planet. Hospitals and health systems can and must become better stewards of human health inside their buildings-and outside of them. This article briefly outlines the history and evolution of what are often called "healthy buildings," as well as the research-informed building-design interventions and operational protocols and policies that advance human health and well-being. A synthesis of best practices, it