By Sue Minichiello
A trend in “Going green” is on the rise in countless offices, schools, hospitals and high-end residential buildings. With multiple benefits—including a remarkable ROI—the addition of green walls (also known as living walls or vertical gardens) is becoming far more common, and for good reason. Years of research champions this type of “biophilic design” as a strategy to improve health and overall well-being. It reduces absenteeism and workplace stress; boosts worker productivity, student performance and patient recovery; improves indoor air quality; lowers energy costs and more.
“We’re not just a pretty face anymore. We’re a solid ROI,” said Bruce Crowle, co-owner of Atria, Inc., a corporate horticultural service company in Connecticut. “The value of green walls has long been misunderstood and underrated, but we’re seeing a huge shift in this thinking, because biophilic design has become a key element of architecture and design. And people now understand that it’s not just a nice amenity; it has profound economic benefits.”
Green walls are, as the name suggests, vertical wall-like structures that are covered in live vegetation. There are different types. Some include integrated hydroponics technology. Some are attached to the building’s HVAC/air-return system (known as “active” systems). Some are 100 percent water efficient, meaning there is zero water waste.
Biophilia is the scientific term for humankind’s innate biological connection with nature: that human beings have an inherent need and desire to affiliate with nature and living systems. Today, with about 80% of the US population living in urban and suburban areas and spending 90% of its time indoors, we are more disconnected than ever from nature. We simply aren’t getting what we instinctively need. This nature deficit has huge implications for physical and mental health and for practical workplace, academic and healthcare issues.
Examples of biophilic design include: landscape artwork and other nature-inspired decor, windows with a view, artificial skylights and green walls. Green walls are perhaps the perfect representation of biophilic design, as they provide:
- A visual connection to nature through real foliage that grows, flowers and changes as in the natural world
- Non-visual connections to nature like aroma, sound (such as rustling leaves and flowing irrigation), and humidity changes
- Natural ventilation and cleaner air because the plants act as natural air filters, and the green wall can be integrated into HVAC systems
According to environmental consultants Terrapin Bright Green, “Scientific studies have proved the physical, psychosocial and practical benefits of biophilia. Biophilic design is both a restorative design strategy and a competitive business opportunity, driving innovations in aesthetics, functionality and sustainability that lead to positive gains in productivity, increased healing rates and even enhanced learning comprehension.”
Increasing Employee Productivity, Health & Creativity
Simply put, biophilic design makes for a happier, healthier and more productive workforce. Here are a few examples:
- Today’s productivity costs are 112 times greater than energy costs in the workplace. Stress decreases productivity. Multiple studies have shown that the presence of plants lowers employee workplace stress. In one such study at Washington State University, participants working in an environment with plants proved 12% more productive than those in an environment without plants.
- A Texas A&M University study explored the impact of plants on creativity in the workplace. The study included male and female participants. All participants in the office environment with plants demonstrated more innovative thinking. The men generated 15% more ideas overall, while the women generated more creative and flexible solutions.
- According to a 2010 US Department of Labor report, the annual absenteeism rate in the US is 3% per employee in the private sector and 4% in the public sector, costing employers $2,074 and $2,502 per employee per year respectively. And, considering a 2011 study of an administrative office building at the University of Oregon proved that 10% of employee absences can be attributed to architecture with no connection to nature, an investment in biophilic design can yield a huge financial return.
- Elevated levels of carbon dioxide indoors negatively affect employee concentration and productivity. This is one of the reasons that, when people are working in a well-sealed building, they often become drowsy and lose focus over the course of the day. According to Green Plants for Green Buildings (GPGB), “It has been calculated that a minimum of 300g (10 oz) of carbon dioxide can be eliminated from an enclosed environment for every square meter of leaf surface in the area per year. Over a year’s time, this amounts to a removal of six cubic feet of Co2 gas.”
“The research confirming that biophilic design makes a workplace more productive cannot be denied, and that is key for businesses and institutions considering green walls,” Crowle said.
Improving Air Quality & Reducing Energy Costs
As buildings continue to be tightened up to increase energy efficiency, chemical contaminants have nowhere to go. They linger in the air, largely recirculated by HVAC systems. The top three culprits are trichloroethylene, benzene and formaldehyde. These Volatile Organic Compounds (VOCs) can be found in carpeting, furniture and building materials, like paints and varnishes. Other substances like carbon monoxide and nitrogen dioxide are also prevalent indoors. The presence of such toxins led to what became known as “sick building syndrome.” They contribute to lethargy and headaches, and exacerbate conditions like asthma, allergies and even the common cold.
“The more airtight we make buildings, the more VOCs increase. If we can reduce VOCs in a building environment, we reduce problems for workers like itchy eyes, sneezing, colds and respiratory distress,” said Crowle.
One of the greatest benefits of green walls is their role as natural air filters. The entire plant system—foliage, soil and roots—detoxifies the air. According to GPGB, “When plants transpire water vapor from their leaves, they pull air down around their roots. … The root microbes convert substances in the air, such as toxic chemicals, into a source of food and energy … and they become more effective at converting toxic chemicals into food the longer they are exposed to the chemicals.” Basically, plants take in harmful substances and churn out oxygen. What’s more, plants can reduce particle pollution like dust and pollen.
Green walls also produce significant energy cost savings. Through transpiration, plants cool their surroundings. Studies have shown that a green wall filled with hundreds of plants can reduce room temperatures by up to 45 degrees and cut electric costs by 20%. In winter, the extra layer of air between the wall of plants and the building wall acts as insulation and reduces escaping heat and incoming cold air.
The profound impact of green walls and other types of biophilic design on the health and well-being of individuals and the financial return for business and facility managers and owners is undeniable. There seems no doubt that the field will continue to grow.
“The industry continues to gain momentum and credibility as people catch up with the science and the proven financial benefits,” Crowle said. “Today, LEED offers points for green walls, you can get a degree in biophilic design, and its becoming part and parcel of new building environments. We’re getting there, and we have every confidence that one day, all indoor spaces will incorporate this type of design.”
(images courtesy of GLTi)