Sustainable Design for Schools
Sustainable Design and Student Performance
"The environment of a given educational facility has a considerable effect on the daily activities of those using the facility. Students, teachers and staff can’t always verbalize what they like about the physical details of a building but they recognize the effect the building has on them. Research has shown that the condition of a school building definitely affects student achievement and student behavior and that there are elements of facility design that are perceived to improve the learning climate (Maiden, 1998, p.40)."
Increasingly, research is demonstrating that the quality of a building, the materials used, indoor air quality, interest-grabbing design features, use of daylighting, acoustic designs and more, impact the performance of those who use a school building. The conclusions seem self-evident. Would we want to work in an environment that was dark, unevenly heated or poorly ventilated?
It is critically important that the design, planning and construction of any school be based on the understanding that the physical facility influences the learning climate. A convincing argument may be made for the use of sustainable design practices in planning for new school construction precisely because that practice is so intimately tied to the whole design of a school and its siting both within a community and on a particular piece of land. By using a holistic approach to design, a sustainable design process is able to more fully consider the needs of all stakeholders who will be using the school. This approach to new school design and building stands in contrast to the more traditional emphasis on cost containment - a primary responsibility of administrators - and on technical design - a primary responsibility of architects and builders. Under a traditional scenario, the idea of building to create a learning environment would most likely be stated as the goal, but the process used to meet that goal could preclude achieving it.
We have invested enormous amounts of time and money in building schools. We have a vested interest in keeping those who attend school for work, learning and play productive and healthy. Investments in sustainable design will pay off in improvements in performance, productivity and attitudes. Those investments are rewarded by meeting needs on a number of different levels.
Health is multi-dimensional and includes not only physical factors but also psychological and social well–being. We have, as humans, basic instincts for both "survival needs" and "well-being needs." Survival needs include environmental health factors such as air, water and acoustic levels. Well-being needs include factors that affect both social and psychological health.
There are several design features that are becoming recognized as important contributors to enhanced student performance and to a sense of well-being on the part of students, teachers and staff. The premise behind inclusion of those features is that the better people feel about their personal health and their work environment, the more able they will be to work productively. The following discussion explores the features that translate into positive results for school occupants. Those features include daylighting (use of natural lighting), acoustic design, attention to materials and mechanical systems that affect air quality, and incorporation of natural environment features to enhance well-being.
Adequate lighting is an important feature of any learning environment. If lighting is insufficient, students will be less able to perform "visual learning tasks" (Maiden, 1996, p. 42). On the other hand, lighting that is too intense may interfere with the learning environment by creating excessive glare and/or heat. Considerations of lighting, therefore, become not just an issue of how much, but also of quality. Quality of light is related to brightness, width of spectrum and glare (CAE: Does Design Make a Difference?, 1997). Quality is affected by both the source of lighting and the finishes of interior spaces. For example, how is the quality of the light affected by wall painting and other interior finishes such as flooring and furniture?
In an article entitled "School Sense," Üllik Rouk states that: "The effect of lighting in a learning environment has to do with a lot more than students’ visual comfort. There is mounting evidence that lighting also affects student behavior, health, and academic performance" (Probe, 1997, p. 41). This attitude toward lighting, and in particular daylighting, did not always prevail. For many years, particularly during the energy crunch in the 1970s, schools were designed without windows. The goal behind this design was to save energy, reduce vandalism and remove outside distractions. Districts reasoned that windowless buildings would stay cooler in warm climates, demand less energy for cooling and, thereby, translate into budget savings.
Subsequent studies showed that windowless classrooms were more of a deterrent than a benefit to student learning. For example, rather than being a distraction to students, "transitory window gazing" actually offers benefits from what is described as "soft" attention. Without windows to provide a "soft attention" break, students will seek a break from attentive listening by perhaps doodling in a notebook. This is considered a "fixed focus activity." According to Rouk, it is much easier for students to refocus their attention on the teacher after a few moments of soft attention than it is after engaging in activities that require a more pointed focus (Probe, 1997).
The first research on the positive effects of light occurred in the early 1980s. More recent research by the Alberta Department of Education, from 1987 to 1991, considered the effect of different lighting types on the children's health. The study compared differences in children's health in rooms with full-spectrum fluorescent light, full-spectrum fluorescent with ultra-violet enhancement, cool-white fluorescent, and high-pressure sodium vapor (HPSV). Full-spectrum light, although still artificial, has all the spectrum characteristics provided by daylight, including activation of the skin's precursors for vitamin D, an essential nutrient. Because the other types are less than full-spectrum, their benefits are reduced.
The text of the Alberta study did not specify the controls used to insure the validity of the study’s conclusions. However, the results that were put forth indicate a benefit of full-spectrum lighting over other, more limited spectrum types and, in particular, HPSV. Under full-spectrum light, students attended school 3.2 more days per year, had less tooth decay, showed more growth gain in height over a two-year period, and achieved better academic performance than students attending schools with other types of lighting (Hathaway et al., 1992).
Rouk describes another study conducted in the latter part of the 1990s by Michael Nicklas and Gary Bailey of Innovative Design. They compared student achievement in three middle schools they had designed for a county in North Carolina to achievement scores in other schools in the same county. Achievement was measured by using two different standardized test scores from the years 1987/88 to 1991/92 for one test and 1992/3-1994/5 for a second test. Results between the two testing systems were not compared. In addition the authors noted that, to minimize the problem of false comparisons, relative (percentage) improvement within each school was used for significant comparison, not the actual average scores between schools. Nicklas and Bailey found that students in classrooms with large windows and skylights that let in natural light outperformed other students in their school district by 5 to 14 percent on end-of-grade tests. (Nicklas and Bailey, 1995).
The Innovative Design study looked at the benefits of daylighting because more people are coming to the conclusion that natural light is an important part of school design. It has two benefits that are significant to the management of a school district: it helps to minimize energy use and increase performance and productivity. In a separate study of the daylit schools’ energy performance, Nicklas and Bailey concluded that the daylit schools used 22 to 64 percent less energy than non-daylit schools. They also noted that the payback on all the new daylit schools was below three years, a significant benefit to the school district (Nicklas and Bailey, 1995).
Additional research continues to document these benefits. The CAE article entitled "Does Design Make a Difference?" (1997), describes the results of a study conducted by Paul Grocoff, Ph.D., to measure impacts of different lighting environments on student behavior and perceived behavior. The description of his results does not include any detail about the size of the study, the parameters and controls, or a clear definition of the terms used to describe student and teacher behavior and reactions to the varied lighting environments. The summary description does, however, indicate how students and teachers may respond to varying levels and qualities of light intensity.
Grocoff found that under the lighting systems he tested the students felt "the worst" under the traditional classroom lights – those with warm white fluorescent lamps at a power of 3000 kilowatts. The teachers also felt their behavior was "not at its best." The students felt "the best," and the teachers felt they behaved at their best, under skylights, or natural lighting. The students found the natural light to be "comfortable," and the teachers appreciated the low glare, good color rendition, and good behavior demonstrated under the conditions created by skylights (CAE, 1997, p.16).
Daylighting, allowing natural light into buildings through use of windows and skylights or other specially designed means, offers many benefits to schools. Research documents improved student performance and significant energy savings – up to 50 percent according to Barbara Erwine formerly with the Lighting Design Lab (Ohrenshall, 1999). Daylighting helps fulfill emotional needs for a connection to natural environments by allowing visual viewing. It enhances colors, renders them more "naturally" to the human eye. By paying attention to lighting, provisions for daylighting and glare control, school districts will be more successful in designing a school that, through conscientious design decisions, supports and enhances the learning environment.
In August 1999, a rigorously documented study looking at the effect of daylighting on human performance was made public. The study, entitled "Daylighing and Productivity Study," was sponsored by Pacific Gas and Electric Company and conducted by the Heschong Mahone Group. The study looked at "the effect of daylighting on human performance and focused on skylighting as a way to isolate illumination effects from other qualities associated with daylighting from windows, such as view and ventilation" (Heschong Mahone Group: Condensed Report, 1999, p. 4). Rigorous controls were used to insure the quality of the data collected. Careful analysis was conducted to select the grade levels and schools to use for the study. Elementary schools were chosen from three school districts in different regions of the western United States. Math and reading test scores were analyzed for over 21,000 students from those districts. In Seattle and Fort Collins, Colorado school districts, scores from the end of the school year were measured. Scores for a third district, in San Juan Capistrano, California, were measured over a school year to track the amount of change from the beginning of the year. A summary of the findings follows:
"Controlling for all other influences (in the Capistrano school district), we found that students with the most daylighting in their classrooms progressed 20% faster on math tests and 26 % on reading tests in one year than those with the least. Similarly, students in classrooms with the largest window areas were found to progress 15% faster in math and 23% faster in reading than those with the least. And students that had a well-designed skylight in their room, one that diffused the daylight throughout the room and which allowed teachers to control the amount of daylight entering the room, also improved 19-20% faster than those without a skylight. …students in classrooms where windows could be opened were found to progress 7-8% faster than those in rooms with fixed windows.
"Students (in Seattle and Fort Collins) in classrooms with the most daylighting were found to have 7% to 18% higher scores than those in rooms with the least.
"The three districts have different curricula and teaching styles, different school building designs and very different climates. Yet the results of the studies show consistently positive and highly significant effects. This consistency supports the proposition that there is a valid and predictable effect of daylighting on student performance (Heschong Mahone Group, 1999, p.2)."
The reason why natural lighting improves student performance has not been ascertained. What is it about daylighting that might cause such an effect? The authors of the "Daylighting in Schools" study offered a number of informed guesses. They are listed below.
- Improved visibility due to higher illumination levels
- Improved visibility due to improved light quality, including better distribution of light, better color rendition, absence of flicker and sparkle or highlights on three-dimensional objects
- Improved health
- Positive occupant response due to decreased daylight deprivation
- Improved mood
- Higher levels of alertness
- Improved behavior
In the past, schools have often used a standard layout of artificial lighting to illuminate classrooms and other areas of school use. Now, in keeping with the principles of sustainable design, it is important to create lighting plans that are suited to individual schools, sites and locale. Lighting requirements will vary significantly across the nation depending on the hours of direct available daily sunlight and the intensity of that sunlight in each different locale. The influence of daylighting and artificial lighting has been documented. The challenge for school districts is to take that information and fit the design to meet the needs of their school sites.
Another design feature that impacts student learning is acoustics. Because younger children learn language through hearing sounds, it is important that acoustics designs account for this need by designing spaces that will meet noise level standards. This need is also relevant in environments with hearing impaired children. For those children, poor acoustic design that results in noisy, reverberant classrooms may create barriers to learning. Major sources of noise levels are heating, ventilation and air conditioning (HVAC) systems and insufficient or poor use of sound-absorbing materials.
A report by the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE), April 1999, includes summaries from three people who spoke at a conference about the effect of acoustical barriers in the classroom. Peggy Nelson noted that typical classrooms often have background noise levels between 35-45 decibels. The high/low range corresponds to whether the HVAC system is on (high) or off (low). When the rooms are occupied, the decibel numbers rise to 58-62. Based on acoustical studies this range is considered to result in poor hearing conditions. For comparative purposes, and to better understand the impact of the higher decibel numbers, it is interesting to note that the City of Seattle sets a noise standard of 60 decibels for commercial use areas (Saperstein, 2000).
Nelson also notes that a study of an acoustics condition rating index shows that the age of listeners has little impact on score results when acoustics are within an acceptable decibel range. However, when conditions swing to the higher noise levels, the ratings index drops for younger children compared to adults in the same space. This suggests that younger children have a harder time comprehending and listening when background noise levels are too high.
Another speaker, Sigfrid Soli, supported Nelson's information by concluding that low-background-noise environments provide a "level playing field" for many (if not all) students. In contrast, high-background-noise classrooms impose barriers to hearing for a range of students. Because a child’s ability to sort "signals" from among noises is not fully developed until teenage years, the ability to learn is compromised by ambient background noise. Soli listed a number of factors that, through a calculation of decibel "penalties," create poor hearing conditions for children. Those factors are age, hearing status, lack of language proficiency, ranges of individual differences in hearing and excessive reverberance in a room. For any one of those factors, higher noise levels exacerbate the ability of children to learn. Combine those factors into one room and the result is to severely compromise a child’s ability to learn.
According to the ASHRAE report, new federal rules are likely to be developed in 2001 in response to complaints regarding poor classroom acoustics and the obstacles to learning those classrooms present for hearing-impaired students. The article suggests that those regulations, if implemented, are likely to change design approaches to HVAC systems. Interestingly and particularly relevant to sustainable design practices, one of the speakers, Jerry Lilly, spoke directly about the contribution of HVAC systems to classroom noise. He was quite clear in stating that low-first-cost HVAC systems will result in problems. The implication, then, is that if HVAC systems are to be used, consideration of the impact on all school operations must be weighed against the purchase and installation costs.
Between the ages of 5 and 18, a student may spend 14,000 hours inside a school building (Environmental Defense Fund, 1999). In consideration of the amount of time children spend indoors, it is important that the air quality in schools be good. In addition, according to the American Academy of Pediatrics, children are more severely affected by air pollution than adults. "Air pollution affects children more than adults because of their narrow airways, more rapid rate of respiration, and the fact that they inhale more pollutants per pound of body weight" (Environmental Defense Fund, 1999, p. 1). Air quality, then, is another factor for the school community to consider in order to create a school with a healthy environment for the children and adults who will use the facility.
Similar to the 1970s decision to eliminate windows as one means to reduce energy costs, school officials also sealed the buildings tightly to reduce air flow that might increase the need for energy expenditures. This decision resulted in air quality problems for schools because ventilation was reduced and pollutants sealed in. The U.S. General Accounting Office acknowledged this problem by reporting in 1995 that more than half the nation’s schools had experienced indoor air quality problems (Environmental Defense Fund, 1999).
Any new school building must be designed with careful consideration to assure a high level of air quality. Problems that are not anticipated can result in expensive repairs for school districts. The Bainbridge Island School District, for example, experienced air quality problems in some of its schools and, as a result, specifically included air quality performance standards for a new school building in order to avoid similar problems. Their experience is described in the case studies section.
In an Environmental Defense Fund article entitled "Making Our Children’s Schools Safer and Healthier" (1999) several steps are suggested for achieving better air quality in schools. They include minimizing exposure to toxic materials through careful selection of furniture, paint, adhesives, floor coverings and supplies, and providing high quality systems for ventilation.
An article in School Planning & Management (1999) warns about the national escalation of allergies and asthma among children. The article describes the problem as a "national crisis." Although the article points primarily to old and decaying schools as the major source of the problem, it also points out that, although outdoor pollution has improved over the last 20 years, pollution levels indoors have increased. These factors make it imperative for schools to pay careful attention to the design and use of HVAC systems.
Up to this point, the discussion has centered on particular environmental hazards that, if not addressed in planning for new school construction, can reduce the quality of a building’s environment. Because communities and the schools within them are so intensely invested in the children and adults that use the facilities, it makes sense to create a building that keeps people productive and healthy. In a paper entitled "Toward a General Theory of the Human Factors of Sustainability," Heerwagen, Winn and Hase (1999) argue that those features are necessary but not totally sufficient to generate...
"the kinds of positive impacts envisioned in the green building community….we argue that successful green buildings will integrate sustainable technologies with design features that sustain human emotional, social and cognitive needs (p. 1)."
The authors use the terms "well-being needs" as opposed to "survival needs" to frame their argument. They borrow the terms from a 1971 article by S. Boyden entitled "Biological Determinants of Optimal Health." Survival needs deal with aspects of the environment that directly affect human health, such as clean air and water. Well-being needs relate to quality of life and psychological health. Because so much attention has been given to environmental factors that affect survival needs, the authors focus their attention on the benefits of incorporating the "psycho-social components of health" into building design. Although their study is not specifically centered on schools, its arguments are easily transferred to a school environment.
The authors argue that if sustainable building practices are aimed at influencing health in a comprehensive way, then the notion of health as multi-dimensional must be recognized. Sustainable design and green-building discussions have centered most commonly on the physical components of health. The authors document research from a diversity of sources and note the importance of "biophilia." Biophilia refers to "humanity’s innate attraction to and affiliation with nature. Taken as a whole, this diverse body of research suggests that buildings which incorporate features of preferred natural settings will be more supportive of human well being than settings which lack these features" (Heerwagen et al., 1999, p.2).
If we consider that buildings are habitats for people, then, by extension, it makes sense that people will choose the "habitat" that is most suitable to their survival. They will gravitate towards a "preferred environment." The authors, using references to support their argument, provide a table that lists habitat and natural feature attributes of preferred environments. It includes "key dimensions" such as "prospect" or the ability to see into the distance, "refuge" or a sense of enclosure or shelter, and "vegetation" that includes large trees with spreading canopies for refuge and shade, flowers and shrubbery (p. 4).
The authors’ argument makes a link between nature and preferred environments and the resulting outcome of "positively toned emotions" on the part of people who work in buildings with preferred environmental attributes. In other words, sustainably designed buildings, if they take into consideration natural habitat attributes along with attributes that promote physical health, can positively influence well-being and productivity.
"A significant body of research compiled by Alice Isen and her colleagues at Cornell University (Isen 1990; Isen et. al., 1987) have found that positively toned emotions can have surprisingly strong impacts on cognitive performance. Positive moods facilitate creative problem solving, decision strategies on complex tasks, discriminative learning, and memory. Although the exact mechanisms by which these cognitive effects occur are not known, Isen and others (LeDoux 1996) suggest that positive moods:
- generate neural patterns associated with broad searching
- promote novel juxtapositions of ideas, concepts, and memories’
- enable people to "break set" more readily and see additional features and associations
- create a more complex cognitive context associated with a broadened focus of attention and greater access to materials store in memory (p. 6)."
The paper presented by Heerwagen et al. argues that sustainably-designed buildings that incorporate features and attributes of preferred natural settings and nature stimuli can have a significant impact on human well-being and productivity. The authors call for further research to more specifically document the beneficial links. The studies cited and the arguments made by the authors are not school-specific so any design needs to be modified to take into account the special needs of schools and children. The benefits, however, to linking physical health and well-being to design outcomes is clear. Schools need to address the health of the whole child as well as the health of adult employees. Believing that health is multi-dimensional, physical, emotional and social health are all factors that need to be included in making design choices for a school building.
The next section features case studies that illustrate sustainable design and its application in school settings.