and Productivity - CEC PIER
MAHONE GROUP's recently completed study on
daylighting and productivity has been summarized and reported by many in print, internet,
radio, and televised media. Newspapers reporting on the study include The Washington Post,
The Seattle Times, The Sacramento Bee, The London Daily Mail, The Christian Science
Monitor, and many more. Over fifty newspapers, international and national, have issued an
article on the study. The newswires of Scripps Howard News, Knight-Ridder Tribune News,
and UPI also issued reports. Lisa Heschong has been interviewed by CBS and National Public
Radio. Below are a few articles.
Study Says Natural Classroom Lighting Can Aid Achievement
By Kenneth J. Cooper
Washington Post Staff Writer
Friday, November 26, 1999; Page A14
© Copyright 1999 The Washington Post Company
School districts across the nation have scrambled to find a solution to dismal
student performance on standardized tests, trying alternative curricula, different
teaching methods, new textbooks, better trained teachers, smaller classes, tutors after
school, Saturday sessions, even longer school years.
But for the most part, school officials have yet to take a close look at the physical
space where learning takes place: the classroom. Could a partial solution to the
achievement problem be to improve the lighting there?
A California architecture consulting firm thinks so, based on its study on the effect
of classroom lighting on achievement levels. The study by the Heschong Mahone Group based
near Sacramento found that students who took their lessons in classrooms with more natural
light scored as much as 25 percent higher on standardized tests than other students in the
same school district.
The study, billed as the first rigorous one of its kind, appears to confirm what some
school designers have asserted based on anecdotal evidence: children learn better under
illumination from skylights or windows, rather than bulbs. The main theory for why this
might be the case is that "daylighting" enhances learning by boosting the
eyesight, mood and/or health of students and their teachers.
John B. Lyons, an Education Department official who monitors school construction, was
briefed on the study last month. "It's one of the first studies that shows a clear
correlation" between daylight and achievement, he said. "I don't discount that
Joseph Villani, associate director of the National School Boards Association, said the
study focused on the kind of "human engineering" issues that boards should
consider in awarding design contracts.
"It's almost common sense if you look at what people prefer," Villani said.
"Most people prefer to have some daylight."
While the Heschong Mahone study is the first to evaluate daylight's impact on learning,
earlier research in Canada found student achievement gains were "significantly
greater" in classrooms where artificial lighting most closely approximated sunlight.
The 1991 study conducted for Alberta's Education Department, subtitled, "A Case of
Daylight Robbery," examined the impact of different artificial lighting systems on
elementary students' test scores, health and school attendance.
The new daylight study, commissioned by the Pacific Gas and Electric Co. out of an
interest in potential energy savings, comes as the nation is on a school construction
spree--spending $20.5 billion this year--to accommodate record enrollments. Its central
finding runs counter to a theory of school design popular in the 1970s: eliminating
classroom windows so that students would not be distracted by goings-on outside.
Test results were analyzed for 21,000 students in Seattle, Fort Collins, Colo., and
Orange County, Calif., areas with divergent weather patterns. Within each of the three
school districts, the results of students in classrooms that let in varying amounts of
daylight were compared.
More daylight appeared to have the greatest effect in the Capistrano district in Orange
County. "We found that students with the most daylighting in their classrooms
progressed 20 percent faster on math tests and 26 percent [faster] on reading tests in one
year than those with the least," the researchers concluded. "Similarly, students
in classrooms with the largest window areas were found to progress 15 percent faster in
math and 23 percent faster in reading."
In Seattle and Fort Collins, the impact of daylight was smaller, raising scores from 7
to 18 percent. The study used a sophisticated statistical method called regression
analysis to control for the social characteristics of students, variations in class size
and other factors known to affect learning.
"We were completely taken aback at the magnitude of these findings. . . . I would
have been delighted to find a 5 percent effect," said Lisa Heschong, one of the
study's authors. "It's an eye opener."
The study did not attempt to explain why students in classrooms with daylight scored
higher. Heschong, an architect, said the theories of other researchers that make the most
sense to her are better vision--artificial light cannot exactly duplicate sunlight--and
"Kids see better, or teachers see better," she said. "It
may be that teachers feel better, are more motivated by daylighting."
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Gets A Good Grade
- Studies: Natural Light Improves Productivity
- Energy Researchers Looked At Schools, Stores
- Body Chemical Melatonin May Be A Factor
Tuesday, June 29,1999 - 01:12 PM ET
© Copyright 1999, CBS Worldwide Inc., All Rights Reserved
New York (CBS) A new study suggests that natural light actually helps
children do better in school and helps stores sell more merchandise. The findings may
change the way many buildings are designed, reports CBS News Health Correspondent Dr.
The authors of the studies in California were not doctors, but architectural researchers
who study buildings.
The research was conducted by an energy consulting firm for the California state Board for
Energy Efficiency and Pacific Gas and Electric Co. The state utility's goal was to save on
energy costs and determine whether sunlight increases human productivity. They were
surprised at how strong the correlation was between daylight and productivity.
First, they examined student test scores and classrooms at three school districts in
California, Colorado, and Washington state. They found that students in classrooms with
the most daylight did 20 percent better on math tests and 26 percent better on reading
tests than students at the same school in classrooms with the least amount of natural
In a companion study, the researchers looked at 108 stores that were part of a large
chain. The stores were virtually identical in layout, except that two-thirds of the stores
had skylights. They then looked at the sales figures for the various stores and determined
that a skylight system increased sales by 40 percent.
The reports are the first large studies of this kind, and were not done by doctors or
peer-reviewed by other experts. But the researchers were careful to control other factors
such as how affluent a community was or where stores and schools were located. They found
that the association between sunlight and productivity were strong regardless of location.
It is not known why daylight might affect human productivity, but one possibility is that
light has an effect on melatonin, a brain chemical that helps regulate sleepiness and
alertness. Sunlight suppresses melatonin, making us more alert and full of energy.
Conversely, too much of the chemical can make people drowsy or depressed.
Doctors suspect that melatonin plays a part in the "winter blues," when people
feel more sleepy and depressed during the winter season. Some doctors use light therapy on
patients who are depressed, having them sit in front of strong lights for a few hours each
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By Carrie Peyton, Bee Staff Writer
(Copyright Sacramento Bee, published June 28, 1999)
Can a few beams of sunshine help lessons soak in?
A new study, one of the largest ever done on natural light in schools, suggests
children learn faster and do better on standardized tests in classrooms with more
Learning rates were 26 percent higher in reading and 20 percent higher in math in rooms
with the most natural light, researchers found.
A companion study found that sales were 40 percent higher in stores with skylights,
compared with almost identical stores in the same chain without skylights.
Psychologists and energy efficiency experts alike have long suspected that something as
simple as sunshine may help people work more efficiently, learn more, call in sick less
often and sell more.
The research, conducted by a Fair Oaks energy consulting firm for the state Board for
Energy Efficiency and Pacific Gas and Electric Co., is one of the largest and most
rigorous attempts to test those suspicions.
"My guess is this will make a huge impact on school design in the next few
years," said Arthur Rosenfeld, a senior adviser for energy efficiency for the U.S.
While stressing he hadn't yet read the studies, Rosenfeld described the review team
that evaluated them as "a star group," and said their level of certainty is
"very, very impressive."
Rosenfeld heads a subcommittee of the National Science and Technology Council that will
be reviewing hundreds of reports on the issue this summer, in an effort to separate
hunches from evidence.
"Until fairly recently, the papers just haven't been convincing," he said.
What tidbits there were, were tantalizing.
A Wal-Mart store improved sales in areas lit by skylights, no matter what merchandise
it put there. Wal-Mart never released any statistics for researchers to analyze, but
within the past year it decided to build all its new stores with more natural light.
Costco and HomeBase both have begun designing new stores with skylights, and Target has
been studying their effect on energy use and sales.
"In retail there's been much more attention to this because of the
economics," said Judith Heerwagen, a Seattle environmental psychologist who helped
review the school data gathered by Fair Oaks architect Lisa Heschong.
"It's absolutely intriguing work," Heerwagen said. "Her results were
pretty consistent across the sites, which suggests there clearly is something going on
The Heschong-Mahone Group brought in statisticians to analyze test scores of more than
21,000 elementary school students in three Western school districts.
In the Capistrano Unified School District in Orange County, where children were tested
at the beginning and end of each school year, a comparison of 750 classrooms showed more
improvement in those with the most daylight.
In those classrooms, students scored 2.3 points higher in reading and 2.5 points higher
in math than students in the rooms with the least daylight.
Over the course of the school year, in all lighting situations, the district's students
on average increased their scores 8.8 points in reading and 12.5 points in math.
In the Seattle Public School District, where students were tested only once a year,
those in rooms with the most daylight had 13 percent higher reading scores and 9 percent
higher math scores than those in the least. Similar testing in Fort Collins, Colo., showed
7 percent higher scores in reading and math.
Heschong said she didn't know what might be causing the effect.
"Daylight is a very complex thing. It affects how we see, and it also affects us
biochemically" in ways that alter alertness, she said.
People also just plain like windows.
"I know I work better when things are open and bright," said teacher Kelly
She said her fourth-graders seemed more attentive and better focused after they moved
from a nearly windowless portable to a bright, newly remodeled classroom at John Holst
Elementary School in Fair Oaks.
The workplace preference for windows is so strong that in Europe, "you're not
allowed not to have access to daylight. It's considered inhumane," said Eleanor Lee,
a specialist in building technologies at the Lawrence Berkeley National Laboratory.
The new daylight research, detailed in twin reports finalized last week, is "one
of the better recent studies that indicates there are effects here worth looking at,"
said Steve Selkowitz, who coordinated the scholarly review of the findings.
"People have tried to study it on a smaller scale, but doing it on a larger scale
with more data sets is important," he said.
Selkowitz, head of the building technologies department of the Environmental Energy
Technologies Division at the Lawrence Berkeley lab, cautioned that there is "a
complicated set of pathways between a cause and an effect."
Virtually everyone, he said, would agree that "the single most important parameter
affecting student scores is the teacher."
Steve Looper, a computer teacher at James McKee Elementary in Elk Grove, said he has
worked in a range of classrooms and never seen a daylight effect.
"There are a lot of other factors that would improve student performance a whole
lot more," he said, such as "getting kids to have enough sleep the night before
or to have breakfast in the morning."
Still, those interested in energy savings from the building technique called
"daylighting" are expecting more research as fascination with the subject
continues to grow.
Interested parties include utilities, which have long advocated buildings that use
skylights, well-placed windows, reflecting surfaces and other designs that let people
conserve energy by turning off electric lights.
The Sacramento Municipal Utility District's light-drenched customer service center
saves SMUD the equivalent of about $56,000 a year in electric bills, an independent study
While the energy conserved by daylighting makes a big difference, nationwide, that's
not as exciting to builders or building owners as its effects on people inside, said
"Very generally, if you look at costs in very round numbers, energy costs about $2
per square foot per year, and people cost about $200 per square foot" in an office
So even a tiny improvement in productivity or sick time will pay off far more quickly
than energy savings, he said.
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