Just as our definition of green building has expanded with time so has our understanding of human health expanded to include not only our physical condition but also our psychological well-being. We have known intuitively for a long time that humans have an affinity for nature, and being in a natural environment—a forest, a park or simply our own garden—can make us feel more relaxed.

The term ‘biophilia’ has been coined to refer to this phenomenon. Scientists have now confirmed that this sensation of relaxation in the presence of nature is the result of a physiological change, a reduction in the level of stress-related hormones produced by our body’s sympathetic nervous system (SNS). Using an approach known as ‘evidence-based design’ (in which detailed analyses of occupant responses to a building’s physical characteristics are used to inform the design of future projects), healthcare architects have begun to explore the physiological benefits of biophilia in the design of indoor environments. This has led to the greater use of natural daylight, access to views of nature, and the introduction of wood and other natural materials into healthcare facilities.

Wood in particular is visually warm and contributes to a socially positive experience for building occupants. People respond emotionally to wood and are attracted to its visual variety and natural expressiveness. A study carried out by the University of British Columbia and FPInnovations1 confirms the value of these attributes. The joint research project found that the visual presence of wood in a room lowers SNS activation in occupants, further establishing the positive link between wood and human health.