The Approachable Green: Integrating Living Walls in Biophilic Interior Spaces
Sourced from the ASLA’s The Field
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” [1]. 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 [2]. 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 [3]. Unfortunately, most of the world’s population now lives in urban environments, with up to 95% of their lives spent on indoor activities [4]. Luckily, there are ways to establish nature connectedness from interior spaces, such as via indoor plants and nature views [5].
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 [6]. 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 [7].
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 [12].