by Shan Jiang, Ph.D.
Biophilia and Biophilic Design
The term biophilia was coined by German psychologist Erich Fromm to describe the physiological tendency towards all living-beings—the “passionate love of life and of all that is alive” . Later, E.O. Wilson and Stephen Kellert’s groundbreaking introduction of the Biophilia Hypothesis to the design disciplines helped reveal the mechanism of humans’ inherent inclination to nature and other lifelike processes from the biologistic and evolutionary perspectives . It is widely encouraged to have direct contact with nature in outdoor settings, such as roaming in the woods, gardening, or simply watching nature from a park bench. A recent scientific study found that visiting nature more than once a week was significantly associated with better health and higher quality of life . Unfortunately, most of the world’s population now lives in urban environments, with up to 95% of their lives spent on indoor activities . Luckily, there are ways to establish nature connectedness from interior spaces, such as via indoor plants and nature views .
The Multifaceted Benefits of Living Walls
According to Stephen Kellert and colleagues’ biophilic design framework, the integration of daylight, natural materials, and vegetation are the fundamental applications that reconnect people to nature. While incorporating a courtyard could be constrained by spatial programming or financial limitations, a vertical greening system could be a great substitute . A vertical greening system, also known as a vertical garden, a living wall, or simply a green wall, provides numerous benefits to the indoor occupants and the environment at large.
As outlined by Green Roofs for Healthy Cities (GRHC), there are different types of living wall systems. Green facades support climbing vines or cascading ground covers that are rooted in soil beds at the bottom or different levels of the structure. Living walls are pre-vegetated modules that are affixed to a vertical structure that support a much lusher mixture of plant species. Living walls can be broadly classified into three systems—the panel system, felt system, and container and/or trellis system .
Living walls that are external to the building envelope function as passive systems for energy savings on buildings or urban green infrastructure that reduce surface temperature, reduce urban heat island effect, and increase urban biodiversity and resilience [7-9]. The well-documented benefits of living walls include the improvement of indoor air quality and noise control [10-11]. A recent literature review study highlights the environmental benefits of living walls proven by empirical studies, including thermal comfort, moisture, wind flow, building energy consumption, carbon sequestration, improving air quality, acoustics, biodiversity, restorativeness, and well-being .
The positive outcomes associated with living walls are multifaceted and societal. A recent study found that installing living walls in classroom-learning environments could facilitate project-based curriculum development, connect students interactively with indoor nature, and have the potential to inspire real-world thinking related to science, technology, engineering, art, and mathematics . A living green wall mural, designed by ArtWorks, was created in the historic district of Cincinnati to brighten the neighborhood through creative placemaking. The living mural, named Looking to Tomorrow, incorporates a built-in irrigation system that supports the plants to grow and thrive, becoming a metaphor of “the literal and figurative growth of the community.”
To learn more, Green Roofs for Healthy Cities has detailed information about different systems of green walls and the environmental, social, and health benefits.
Today’s post covered the scientific underpinnings of living walls—stay tuned for part 2, which will cover a few case studies and will appear here on The Field next week!
 Fromm, E. (1973). The Anatomy of Human Destructiveness. New York: Fawcett Crest.
 Wilson, E. O. (1984). Biophilia. Harvard University Press.
 Martin, L., White, M. P., Hunt, A., Richardson, M., Pahl, S., & Burt, J. (2020). Nature contact, nature connectedness and associations with health, wellbeing and pro-environmental behaviours. Journal of Environmental Psychology, 68, 101389. DOI: https://doi.org/10.1016/j.jenvp.2020.101389.
 Spence, C. (2020). Using ambient scent to enhance well-being in the multisensory built environment. Frontiers in Psychology, 11, 598859. DOI: https://doi.org/10.3389/fpsyg.2020.598859
 Keniger, L. E., Gaston, K. J., Irvine, K. N., & Fuller, R. A. (2013). What are the benefits of interacting with nature?. International Journal of Environmental Research and Public Health, 10(3), 913-935. DOI: https://doi.org/10.3390/ijerph10030913
 Kellert, S. R., Heerwagen, J., & Mador, M. (2011). Biophilic Design: The Theory, Science and Practice of Bringing Buildings to Life. John Wiley & Sons.
 Loh, S. (2008). Living walls–a way to green the built environment. Environment Design Guide, 1-7.
 Coma, J., Pérez, G., Solé, C., Castell, A., & Cabeza, L. F. (2014). New green facades as passive systems for energy savings on buildings. Energy Procedia, 57, 1851-1859.
 Ling, T. Y., & Chiang, Y. C. (2018). Well-being, health and urban coherence-advancing vertical greening approach toward resilience: A design practice consideration. Journal of Cleaner Production, 182, 187-197.
 Shao, Y., Li, J., Zhou, Z., Zhang, F., & Cui, Y. (2021). The impact of indoor living wall system on air quality: a comparative monitoring test in building corridors. Sustainability, 13(14), 7884.
 Chang, L. T., & Chang, F. C. (2022). Study of Living Wall Systems (LWSs) Support system for improving LWSs Life cycle performance and noise reduction potential. Building and Environment, 216, 109007.
 Gunawardena, K., & Steemers, K. (2019). Living walls in indoor environments. Building and Environment, 148, 478-487.
 McCullough, M. B., Martin, M. D., & Sajady, M. A. (2018). Implementing green walls in schools. Frontiers in Psychology, 619. DOI: https://doi.org/10.3389/fpsyg.2018.00619
Shan Jiang, Ph.D., is Director of Research at GBBN Architects and Chair of ASLA’s Healthcare & Therapeutic Design Professional Practice Network (PPN).