by By Kenneth Freeman — The international fiscal nightmare, which adds untold stress to our lives, is an ideal time to take ownership of our interior environment to ensure a sensory experience that evokes harmony and tranquility. Who can fail to be charmed by the graceful arch of palm leaves or the exotic beauty of orchids? However, research has shown that the value of plants goes far beyond the purely aesthetic. Plants are actually good for the building and its occupants in a number of subtle ways. They are an important element in providing a pleasant, tranquil environment where people can work or relax. As the financial markets go through a roller coaster ride filled with bumps and scares, it is more important than ever to ensure that the elements you can control provide sensory satisfaction.
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As humans, we are consciously and sub-consciously affected by everything that touches our five senses. Our moods and behaviors are altered by the aromas that surround us—the artwork we gaze at and the plants that populate our interior spaces. Our environments are multi-layered and there is no better time than now to ensure that each layer of our interior world speaks to our soul and enhances our well-being. Improving one’s environment is not frivolous as it has bottom-line results for both personal health and work performance. Research studies provide concrete data to support an enhanced environment.
Plants improve the environment
Tests carried out by Rentokil Initial’s research and development department suggest that interior plants can absorb, diffract or reflect background noise in buildings—thereby making the environment more comfortable for the occupants. The effect appears to be dependent on plant type, planting density, location and sound frequency.
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To investigate the potential acoustic benefits of interior plants in more detail, further research was carried out by post-graduate student Peter Costa at South Bank University, London. To quantify the acoustic effect, the sound absorption coefficients of a number of plant species were measured and compared with other building materials. The higher the absorption coefficient, the better the material is at absorbing sound—a coefficient of 0.25 means that a quarter of the sound is absorbed; 0.50 refers to half the sound and so on. The study indicates that plants are generally more efficient at absorbing high sound frequencies than low ones.
Good examples of plants that are efficient at absorbing high sounds are Spathiphyllum wallisii (Peace Lily), Philodendron scandens (Sweetheart Plant), Dracaena marginata (Madagascan Dragon Tree) and Ficus benjamina (Weeping Fig). High frequencies cause the most irritation to building occupants, so the benefit of having plants becomes clear.
Green buildings beat sick buildings
There is general agreement within the scientific community that plants improve the indoor environment and may be useful weapons in the fight against the modern phenomenon known as sick building syndrome. No specific cause of sick building syndrome has been identified, but poor air quality, excessive background noise and inadequate temperature and light control are thought to be important factors. Because plants have a large surface area and exchange water and gases with their surroundings, they have a unique ability to tackle many environmental problems.
In particular, plants can reduce levels of carbon dioxide, which can accumulate in buildings from the breathing of its occupants and the by-products of heating systems and electrical equipment. Plants increase relative humidity (RH), which should be between 40 percent and 60 percent RH for maximum human comfort, and reduce levels of certain pollutant gases, such as formaldehyde, benzene and nitrogen dioxide. They also reduce airborne dust levels, air temperatures and background noise levels. In short, every plant is a miniature air-conditioning and purification system.
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| Well-maintained plants promote a sense of well-being at the office. |
Plants as stress relievers
The relationship between a person’s psychological well-being and the presence of plants has always been somewhat speculative. Many people instinctively feel that plants have positive effects, although there has been very little proof—until recently. Scientific reports from researchers at universities in the United States, the Netherlands and the United Kingdom shed new light on the effect plants can have on the stress levels and productivity of office workers.
Virginia Lohr and her colleagues at the Department of Horticulture and Landscape Architecture, Washington State University looked at the benefits of adding plants to a windowless workplace—in this instance, a college computer laboratory. Participants’ blood pressure and emotions were monitored while completing a simple, timed computer task in the presence or absence of plants.
“When plants were added to this interior space, the participants were more productive (12 percent quicker reaction time on the computer task) and less stressed (systolic blood pressure readings lowered by one to four units),” reported Lohr. “Immediately after completing the task, participants in the room with plants present reported feeling more attentive (an increase of 0.5 on a self-reported scale from one to five) than people in the room with no plants.”
Further evidence for productivity improvement with plants is highlighted in a review of “the effect of healthy workplaces on the well-being and productivity of office workers” by John Bergs in the Netherlands. Bergs cites both Tøve Fjeld and a study carried out in the Netherlands, at the Winterswijk Tax Office, where the influence of plants on productivity was closely monitored. The study was carried out using a control group (without plants) and a test group (with plants) in comparable areas of the building. The most significant findings of the study included improvements in air quality (both measured and perceived by the employees) and improvements in productivity. Berg found that productivity improved and concentration was enhanced with the strongest link found for those working at computer terminals.
Additional evidence that plants help to reduce stress is provided by Helen Russell, in her dissertation, “The effect of interior planting on stress.” Russell’s study, carried out at The University of Surrey [Guildford, Surrey, England], tested whether the presence of plants in a room affected the stress levels of people undertaking a complex task. Participants were invited to an office that had no plants or one that was heavily planted. Sensors were attached to the skin of the participants to record skin conductivity, heart rate and blood pressure. The participant was allowed to get used to the surroundings for 10 minutes, during which time a base line recording of their stress level was recorded. After this 10-minute period, the participant was asked to add up a list of 78 numbers without using their fingers or counting aloud. Distractions such as the sound of a ringing telephone or traffic noise were played to them at random intervals. After the test, a further 10-minute period of rest was allowed.
Of the three types of measurements made, skin conductivity showed the greatest differences between planted and unplanted surroundings. In the planted office, not only were stress levels lower, but people recovered from their stress more quickly than those in the unplanted office during the 10 minute post-test rest period.
The power of scent
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Do you feel more relaxed as you enter a hotel spa lobby when greeted by subtle notes of lavender? The power of subliminal smells with its ability to alter moods and buying decisions is growing around the world. Even the famed Davos Global Economic Forum isn’t turning up their nose at the power of olfactory—manipulation having hired a scientist to present a range of odors geared at helping delegates tackle the financial meltdown at this year’s event.
Researchers have found a strong correlation between smell and memory. Some businesses are using manufactured scents to elicit positive memories and induce a sense of well-being for shoppers. When in a good mood, a customer may stay in the store for a longer time which leads to greater buyer opportunities for the retailer. Retailers use scent branding to keep customers contentedly shopping. Home fragrance, whether distributed by spray cans, atomizers or candles, establishes the mood and feeling of a residence. Aromatherapists have long used essential oils for healing, emotion and mood. For example, scents such as lavender, vanilla and bergamot have a calming effect while cinnamon and spearmint energize.
Avert bare walls syndrome
Many of us now spend most of our waking lives at work in an office. It is simply no longer a case of wanting it to be a more pleasant place. We need to make our offices happy, inspiring and attractive places to be. While gazing at an original Monet or Matisse in our home or office is unattainable for most of us, we can still gain the psychic and emotional benefits from art with minor investments in fine art posters, prints, photography and limited edition art which work overtime to enliven our workplaces and inspire creativity and communication.
The outside world may be chaotic and unstable but we can control the elements of our interior worlds. By surrounding yourself in an environment that nourishes your senses, you will become fortified. Your tools of survival will be productivity, tranquility and creativity. Take a few moments to explore the possibilities.
About the author
Kenneth Freeman is the international technical director for Ambius, the premier creator of ambience for businesses. An expert in interior landscaping, he has been directly involved in all aspects of research into the benefits of interior plants as well as the development of horticultural best practices. Freeman has developed a wide range of education and training programs and is the author of continuing education programs for architects as part of the Royal Institute of British Architects Continuing Professional Development Core Curriculum, and in the U.S. as part of the American Institute of Architects Continuing Education System. He is based in London, England and may be reached at kenneth.freeman@ambius.com.