The Field

by Shan Jiang, Ph.D.

While part 2 below covers a few case studies, please see part 1 of this post, published last week, for more on the scientific underpinnings of living walls. 

Living Walls in Workplaces

For corporate workplaces where people spend a significant amount of time inside, living walls could vitalize the working environment, add aesthetic pleasure, and play important roles in positively impacting people’s health. According to a scientific report published by Nature, urbanization in Western cities has resulted in a lack of exposure to environmental microbes due to the increased level of hygiene, loss of biodiversity, and irregular contact with soil, which has been linked to many immune mediated diseases. Indoor green walls in urban offices can affect health-associated commensal skin microbiota and enhance immune regulation among  employees [1]. Indoor plants in the workplace were found to correlate with less sick leave, better task performance, and quicker restoration from mental fatigue [2-3].

Workplaces are embracing the idea of bringing nature inside through living walls that maximize space utilization and provide numerous biophilic features. Living walls help to achieve many goals as required by the WELL Building Standard—Air, Water, Nourishment, Light, Fitness, Comfort, & Mind [4]. Duolingo, a leading tech company in the language education industry, has recently integrated several green walls that have become new attractions in their Pittsburgh, Pennsylvania headquarters.

Recent technology development makes living wall structures more flexible and designable beyond “just a green wall.” GBBN Architects’ Cincinnati office experimented with digital fabrication and augmented reality (AR) technology in their living wall design and installation. According to an interview with the living wall designers Mandy Woltjer and Troy Malmstrom, the design concept was to encourage plants to grow out of an irregular trellis that increases multi-dimensional volumes. Therefore, the plants were installed first in an AR space where the designer could precisely locate the plants in the designated position.

Living Walls in Healthcare Environments

A series of interior living walls could serve as micro-greeneries that are easily accessible by occupants from different units of the building, particularly for large facilities with deep footprints in which traveling long distances could constrain people’s use of centralized green spaces. For patients and staff members in large hospitals, interior green walls could offer a “get away” opportunity for respite and recovery from stress.

The TriHealth Baldwin Tower in Cincinnati houses corporate administrative offices for their healthcare workers. Five living walls, each 8 feet tall by 10 feet wide, were installed across different floors in the building as vertical gardens. The living walls feature over 1,000 tropical plants from 20 different species, making it “one of the most extensive living office projects in the entire country” and one that transformed TriHealth’s administrative offices into biophilic environments [5].

Incorporating indoor plants in healthcare environments can enhance patient recovery from surgeries and reduce patient stress. A controlled random trial study found that ornamental indoor plants in patient rooms were associated with higher satisfaction, lower stress and fatigue, lower systolic blood pressure, and lower ratings of pain for patients during postoperative recovery periods [6]. Another experimental study found that participants exposed to the hospital room with indoor plants reported significantly less stress than those in the control condition [7].

Following the success of living walls at the TriHealth Baldwin Tower, a large-scale living wall (a 50-foot-tall installation) was installed in the atrium at the Harold M. and Eugenia S. Thomas Comprehensive Care Center, TriHealth’s new cancer and cardiac care center in Cincinnati, Ohio. Since the living wall is designed for oncology patients with compromised immune systems, the designer worked closely with the hospital’s disease control team to develop inorganic growing materials and an intensified maintenance plan to ensure a sterile living wall for safety and infection control. According to a recent interview with Dr. Tyler Wolf, the founder, designer, and environmental engineer at Urban Blooms, filtered water moves through the living wall following monitored time intervals to retain moisture without leaving standing water, which significantly reduced Legionella bacterium—previously a big concern in healthcare environments when standing water is present. Out of the 2,500 plants grown on the living wall at TriHealth’s Thomas Comprehensive Care Center, only about 40 plants were replaced during the first year of maintenance. The sterile growing material and irrigation system helped achieved a 98% first-year success rate, significantly higher than the 90% first-year success rate for most living walls.

Technologies and the designers’ talents have been pushing the boundaries of living walls in interior spaces. More diversified species including woody plants and fruit trees, such as fig trees and even banana trees, thrived on vertical walls. Adding sensors and intelligent control systems into the living wall could enable remote monitoring and maintenance.

For more, see ASLA’ s article about increasing energy efficiency by using green walls in residential environments, including a list of sources around this topic.

References

[1] Soininen, L., Roslund, M. I., Nurminen, N., Puhakka, R., Laitinen, O. H., Hyöty, H., & Sinkkonen, A. (2022). Indoor green wall affects health-associated commensal skin microbiota and enhances immune regulation: a randomized trial among urban office workers. Scientific Reports, 12(1), 1-9.

[2] Adamson, K., & Thatcher, A. (2018, August). Do indoor plants improve performance outcomes?: using the attention restoration theory. Congress of the International Ergonomics Association (pp. 591-604). Springer, Cham.

[3] Bringslimark, T., Hartig, T., & Patil, G. G. (2007). Psychological benefits of indoor plants in workplaces: Putting experimental results into context. HortScience, 42(3), 581-587.

[4] Suite Plants. (December 20, 2018). WELL Building Standard: Green Walls & Sustainability.

[5] Urban Blooms. (n.d.). Bethesda North – TriHealth Cancer Center.

[6] Park, S. H., & Mattson, R. H. (2009). Ornamental indoor plants in hospital rooms enhanced health outcomes of patients recovering from surgery. The Journal of Alternative and Complementary Medicine, 15(9), 975-980.

[7] Dijkstra, K., Pieterse, M. E., & Pruyn, A. (2008). Stress-reducing effects of indoor plants in the built healthcare environment: The mediating role of perceived attractiveness. Preventive Medicine, 47(3), 279-283.

Shan Jiang, Ph.D., is Director of Research at GBBN Architects and Chair of ASLA’s Healthcare & Therapeutic Design Professional Practice Network (PPN).