Healthy Buildings has become the marketing focus, if not the goal, for an increasing number of projects and organizations in the past five years. The current COVID-19 pandemic has placed a new and compelling spotlight directly onto buildings of all types, whether offices, homes, retail, restaurants, hotels, or schools. The issues are no longer limited to the functional parameters of the building design, construction, maintenance, and use. Neither do the concerns remain within the legacy boundaries of the expansion from indoor air quality (IAQ) to indoor environmental quality (IEQ). The driving concern now is how the parameters of building functioning affect the occupants. To do so requires measurements for assessment followed by measurements for verification. Those measurements do not exist. The public health risk to occupants of buildings, prioritized by the COVID-19 pandemic and climate change, needs complex metrics, both theoretical and practical. The committee discussion and recommendations highlight why there is no operational definition of health, challenges in moving forward, and points to a conceptual and practical direction.