Biological and medical research offer rigorous techniques and scientific methodologies to explore how features of the built environment influence human health, performance, and well-being. Practice guidelines from evidence-based medicine and translational science provide models for translating biomedical information into design principles applicable to healthcare environments. Examples from recent scientific discoveries highlight how scientific evidence may inform healthcare design. The interaction between stress and environmental stimuli such as light, sound, and location are relevant to patients, visitors, and staff, influencing cardiac and stress responses as well as cognitive functions such as memory and navigation abilities. Research demonstrating the pervasive influence of light on human biological systems includes epidemiological and laboratory studies that suggest an association between light exposure and increased cardiac or cancer risk. Advances in laboratory research and the development of wearable devices that may be used on-site in healthcare settings facilitate more precise measurement of the environmental features that influence healthcare users and providers. The data derived may serve as the foundation for new evidence-based performance criteria, supporting the use of existing materials and methods, as well as the creation of new design solutions to meet health needs in addition to operational outcomes.