Research

The need for natural light, part III


Let’s see, which hospital room would you rather stay in? This one (A)?


Or this one (B)?

Carson Tahoe Regional Medical Center, Carson City, NV
As for me, I’d choose B. There are lots of reasons why I think B is better than the A, but high on the list is that B has lots of windows that not only look out onto a view that even homebuyers would pay good money for, but that let in copious natural light as well. 

And so we come to the Part III of “The need for natural light.” 

The benefits of natural light – at home, at work and school, and in the healthcare setting – have been well documented. People fare better when they have access to natural light. For example, a 1998 study found that sun exposure in the workplace environment increased worker satisfaction and performance, including lowering intention to quit and reducing fatigue (that same study, by Leather et al., found that providing views of nature also increased satisfaction, particularly in high-stress environments). A landmark “Daylighting in Schools” study found that students in classrooms with more natural light scored as much as 25% higher on standardized tests than other students in the same school district (see references below for full citation and to link to the condensed study). 

As for healthcare: Roger Ulrich and colleagues have found exposure to natural light to be an important factor in environments for healing. Exposure to sunlight can reduce depression, alleviate stress, and even reduce pain. In addition to providing essential dosages of Vitamin D, sunlight increases our levels of serotonin, which in turn inhibits pain. In their recent literature review of evidence-based healthcare design, Ulrich et al. cite a study by Walch and colleagues of post-operative spinal surgery patients. Patients with sunnier rooms reported less stress and took 22% less analgesic pain relief medication (see Ulrich et al, 2008, below). 

In her new, excellent book A Visual Reference for Evidence-Based Design, Jain Malkin lists daylight as one of the key ingredients in creating a successful Environment of Care: “There is a major focus on the importance of natural light and views, access to gardens, and clarity of wayfinding.” In Chapter 4, “Incorporating Research into Design Features,” lighting is first on the list: “Lighting–both natural and electric–is the most important component of an interior environment. Adequate exposure to natural light is essential for biological health and entrainment of circadian rhythm. Research indicates that patients in rooms that receive more sunlight are less depressed and have reduced length of stay.” Malkin also mentions benefits to staff members (pp. 63-65; see full citation below). 
So what does all of this have to do with therapeutic landscapes? 

Simple: Windows that let in natural light… 

The waiting room at Santa Fe Cancer Center at St. Vincent Hospital 
looks out onto the healing garden (Santa Fe, New Mexico)

…can also offer views to the outside world (even skylights can sometimes give us views of blue sky and/or clouds). As Ulrich et al. state in their most recent (2008) literature review, “Larger windows in patient rooms not only provide natural light, but they also have the potential benefit of offering views of nature and should be considered in the design process.” 

Healing garden at St. Vincent Hospital, Santa Fe, NM 
(note the mirrored windows – they provide privacy for those inside 
while also reflecting the garden to make it appear larger).

And as we know from Ulrich’s and other studies, window views to something more interesting than a brick wall, or the building’s air conditioning system, elicit better outcomes. And the research also suggests that more naturalistic the setting, the better the outcome (again, see Ulrich et al, 2008, below).


Lobby at Carson Tahoe Regional Medical Center, Carson City, NV



All of this research notwithstanding, there are times when natural light can be too much of or not enough of a good thing.

Too much of a good thing

1. When light = sun = heat. In hot climates, keeping light out is one important way of regulating the temperature. Whether inside the building or out, people seek shade when temperatures rise above the human comfort zone. Though it’s beautiful and exemplary in many ways, I’m actually not sure how I’d feel in the above Carson City lobby on a hot day in August…but maybe they’ve got it all figured out with awnings, blinds, or some other technology (besides just more AC). 

2. When light = glare. For example, as I write this, the sun is starting to stream into my office, which would be lovely if it didn’t glance off of my computer screen. Time to draw the curtain. And glare can truly be a problem, especially for people like the elderly who are glare-sensitive. 

3. This last point isn’t so much to do with light as with privacy. The one drawback of a window, especially on a ground floor looking out onto a garden, is that if users inside can see out, then people outside can usually see in. Designers of hospitals with interior courtyards often grapple with the double challenge of the “fishbowl effect” (feeling like everyone can see you when you’re in the garden) and not wanting to violate the privacy of those indoors. Designers have found all sorts of clever ways to address this issue, including at St. Vincent Hospital, above, where mirrored windows allow users inside to see the garden whilst keeping their privacy intact, and users outside get the sense of an even larger and more verdant garden (yep, the old mirror trick can work in the landscape as well).

Window coverings: That 1998 workplace study I mentioned earlier also suggested providing users with ways to control the amount of light (curtains, etc.). As we also know from research, providing people with choices is another way to reduce stress and bolster a feeling of control over one’s environment. Whether those operable window coverings are used to control light for temperature regulation, glare, privacy, or just personal preference, they should be provided whenever possible.
Not enough of a good thing: Seasonal Affective Disorder and Sundowners Syndrome. Sometimes natural light has to be augmented or adjusted, as in these two examples below.

1. Another issue with natural light is that in the winter, there just isn’t enough of it. We’ve all heard of SAD – Seasonal Affective Disorder, and this is a real thing. Just as plants need grow-lights in the winter because even sitting in a sunny windowsill isn’t enough, some people need additional light, too. Full spectrum light therapy, at doses of 2500 – 10,000 lux, has been found to be as or even more effective than anti-depressants for some SAD sufferers. 

2. For people with Alzheimer’s and other forms of dementia, exposure to light and the color of light should be controlled and regulated to avoid mood changes and disruptive behaviors, particularly those brought on by “sundowners syndrome.” In two studies by Melinda La Garce, the effects of “Sundowner’s Syndrome” and other light-related problems were reduced by adding “full spectrum lighting to simulate daylight, shading devices to reduce sun angle change and shadows, and light monitors to keep the light intensity the same throughout the day and evening.” In the 2004 study, La Garce noted that the sun’s altitude, which changes over the course of the year, affects the color, intensity, and angle of daylight. She also found that the color of light seemed to play a stronger role than shadows and light intensity. 

As I’ve mentioned in the past (see, for example, “When the Weather Outside is Frightful”),  indoor atria are another great way to provide access to natural light and nature, even on days when going outside is not an option. This image is of the Fourth Floor Atrium at the University of Alberta Hospital in Canada. To see more examples, link to Shane Pliska’s article in Interiorscape Magazine.

References 

Crockett, Jim (2004). “Healthy Daylight and Healthy Darkness: What our Bodies Need.” Consulting-Specifying Engineer. Click HERE to link to the article.

Darling, Tammy (1993). “Seeing the light: why your body needs regular doses of natural light.” American Fitness, Nov-Dec. Click HERE to link to the article.

Gross, Raz, Yehuda Sasson, Moshe Zarhy, and Joseph Zohar (1998). “Healing Environment in Psychiatric Hospital Design.” General Hospital Psychiatry, Vol. 20, No. 2, pp. 108-114. Read the summary by InformeDesign.

Heschong, Lisa and Heschong Mahone Group (1999). “Daylighting in Schools: An Investigation into the Relationships Between Daylighting and Human Performance.” Commissioned by California Pacific Gas and Electric Company. Click HERE to link to the condensed report.

Horowitz, Steven G., M.D. (1998). “Design Trends: Designing for Advanced Therapeutic Outcomes – Acute Care.” Journal of Healthcare Design, Vol. 7. Read the summary by InformeDesign.

La Garce, Melinda. (2004). “Daylight Interventions and Alzheimer’s Behaviors – A Twelve-Month Study.” Journal of Architectural and Planning Research, Volume 23, Issue 3, pp. 257-269. Read the summary by InformeDesign.

La Garce, Melinda. (2002). “Lighting Affects Behavior of Alzheimer’s Patients.” Journal of Interior Design, Volume 28, Issue 2, pp. 15-25. Read the summary by InformeDesign.

Leather, Phil, Mike Pyrgas, Di Beale, and Claire Lawrence (1998). “Windows in the Workplace: Sunlight, View, and Occupational Stress.” Environment and Behavior, Vol. 30, No. 6, pp. 739-762. Read the summary by InformeDesign.

Malkin, Jain (2008). A Visual Reference for Evidence-Based Design. The Center for Health Design

van Bommel, W. J. M. and G. J. van den Beld (2004). “Lighting for Work: A Review of Visual and Biological Effects.” Lighting Research and Technology, Volume 36, No. 4, pp. 255-269. Read the summary by InformeDesign. 

Ulrich, R. S., Craig Zimring, Xuemei Zhu, Jennifer DuBose, and Hyun-Bo Seo, Young-Seon Choi, Xiaobo Quan, and Anjali Joseph. (2008). A Review of the Research Literature on Evidence-Based Healthcare Design. Published in Health Environments Research & Design Journal, Vol. 1, No. 3, Spring, pp. 61-125. Click HERE to read the abstract. 

Ulrich, R. S., C. Zimring, A. Joseph, X. Quan, and R. Choudhary. (2004). The Role of the Physical Environment in the Hospital of the 21st Century: A Once-in-a-Lifetime Opportunity. Concord, CA: Center for Health Design. Read the summary and access the full report at the Center for Health Design.

Walch, J. M., B. S. Rabin, R. Day, J. N. Williams, K. Choi, and J. D. Kang. (2004). “The effect of sunlight on post-operative analgesic medication usage: A prospective study of patients undergoing spinal surgery.” Psychosomatic Medicine, Vol. 67, pp. 156-163.

The need for natural light, part II (and to be continued)

In researching for this blog posting on the need for natural light, I’ve uncovered so much good information that I wouldn’t be able to do the subject justice to try to write about it today, when I’m crunched for time. So, stay tuned while I do a little more digging and collecting thoughts. 

In the meantime, the best all-around article I’ve found so far is “A Review of the Research Literature on Evidence-Based Healthcare Design” by Roger S. Ulrich, Craig Zimring, Xuemie Zhu, Jennifer DuBose, Hyun-Bo Seo, Young-Seon Choi, Xiaobo Quan, and Anjali Joseph, published in the Spring 2008 issue of Health Environments Resarch & Design Journal, a quarterly journal published by the Center for Health Design and Vendome Group (Vol. 1, No. 3, pp. 61-125). This article (and the journal in general) is a must-read/have for anyone interested in Evidence-Based Design in healthcare. For subscription information, contact www.herdjournal.com.

Winter Solstice (and the need for natural light, part I)

Today is the winter solstice, and this weekend we got blasted with two snowstorms in a row. Winter has definitely arrived! I love the snow, and am delighted (especially since I don’t have to drive anywhere) with the winter-wonderland effect. White Christmas and all that. Almost everything looks better to me with a good dollop of the stuff. 

The only problem with snowstorms is that it tends to be cloudy when we have them. A cloudy winter solstice – already the shortest day of the year – even with the snow falling, can get rather gloomy. So I was happy just now when the storm ended and the sun broke through. I ran outside with my camera into the glittering, glowing whiteness of it all. Just what the doctor ordered: A little exercise, a little vitamin D, a little time appreciating nature close-up, cold fingers and all. 

Remember that post about seedheads? Now I can finally illustrate how beautiful they look (goldenrod, above). 

But I also got to thinking about the importance of light. Plants need light to photosynthesize; humans need light, too, and more research than ever is showing that natural light exceeds artificial when it comes to making us feel good. This means that buildings should be designed for their inhabitants to have as much natural light as possible. On this lovely winter solstice afternoon (and erev Channukah), it’s 4:00, the sun is setting, and it’s almost time to go inside and light the menorah. So stay tuned for tomorrow, when I’ll delve deeper into the research on natural light and the implications for therapeutic landscapes.

New study on landscape preferences

Image courtesy Henry Domke Fine Art
Complexity, openness, and water. According to a 2007 study by Ke-Tsung Han, these are three of the most preferred physical landscape characteristics.* 

One of the questions designers of therapeutic landscapes grapple with is what kind of landscape will elicit the best outcomes for our clients. Even before we think about plant material, we have to decide how the space should be organized. Should it feel open or enclosed? Have a sense of mystery or be instantly “legible” to the user? And then how much plant material to use, and how to use it. To some extent, the answers are dependent on your intended user and on the space you have to work with. Unfortunately, for those who like to design spaces based on research (this is called Evidence-Based Design, or EBD), there’s not a whole lot out there for us to go on. One thing we know for sure: the majority of people, especially in a healthcare setting, prefer a high ratio of green, or “softscape,” to hardscape (paving, walls, etc.). Therefore, the more we can use plant material (rather than hardscape) to create space, the better; and the lusher that environment is, the more restorative it will feel. We have also seen a fair amount of evidence that people like and respond well to landscapes with water. 

This week InformeDesign, one of the best resources for EBD-oriented designers, summarizes a study about such preferences. It’s a great addition to a growing body of research. Click HERE to read the summary, or contact Environment and Behavior directly for the full article. Next, I’d love to see this study repeated with different populations (people of different ages, ethnic backgrounds, countries, etc.), and measured for actual outcomes rather than restorative potential.  

*Han, Ke-Tsung (2007). “Responses to Six Major Terrestrial Biomes in Terms of Scenic Beauty, Preference, and Restorativeness,” Environment and Behavior, Vol. 39, No. 4, pp. 529-556.

Note: The above image was not one used in the study, but I think it illustrates the three physical characteristics of complexity, openness, and water.

Nature-Deficit Disorder: Getting Kids Outdoors (watch the video clip!)

Here’s a nice television clip from CBS and wjz.com about Nature-Deficit Disorder (a term coined by Richard Louv of Last Child in the Woods and the Children & Nature Network). My favorite part is when TV anchor Don Shelby asks kids what “nature” means to them. You can either watch the clip (after a brief but nonetheless annoying advertisement) or just read the transcript. I’ve blogged about Louv before, so if you’re new and you want more, use “Louv” in a keyword search in the column to the right to pull up all relevant posts.

You can watch more news clips and get lots more great information about children and nature on the C&NN website.

And here are two more good related articles that I’ve come across recently:

Research Shows a Walk in the Park Improves Attention in Children with ADHD,” by Frances E. Kuo and Andrea Faber Taylor, 2008. Click HERE to read the University of Illinois at Urbana-Champaign press release.

Amount of green space and childhood obesity:
Neighborhood Greenness and 2-Year Changes in Body Mass Index of Children and Youth,” by Jeffrey Wilson and Gilbert Liu, 2008, American Journal of Preventive Medicine, Vol. 35 No. 6.
Summary by Research Design Connections: “The amount of green space near their homes is related to the weights of inner city children. Children living in inner city neighborhoods with more green space (as determined from analysis of satellite photographs) have significantly lower body mass index changes as they grow taller than children living in areas with smaller amounts of green space.”

Many thanks to Heather for the photo of her beautiful daughter!

Leaves! Raking for Health (yours and your garden’s)

It’s getting cold here in the Hudson Valley (23 degrees this morning) and it’s really starting to feel like winter. The weather has been not only cold but rainy for the past few days, so I didn’t mind this morning because it was bright and sunny – a good day to tackle a chore I’d been putting off for weeks – raking leaves. As a child, this was one of my favorite activities (well actually, “helping” my parents rake and then jumping into the piles of leaves on my hoppity-horse). Now, I tend to dread it, despite the fact that I usually feel good after. In general, I enjoy putting the garden to bed for the winter. Cleaning up, deadheading (though I always leave some seedheads for the birds and for “decoration” – they look beautiful in winter, especially poking out from a blanket of snow with little snow-hats of their own), mulching, and dreaming of next year’s garden. Raking is a big part of that. And it’s good exercise!

An article in Martha Stewart Living from way back in March 2007 (“Reap the Benefits of Gardening,” by Peter Jaret) discusses the psychological and physical health benefits of gardening. Raking is one of many gardening activities that, if done for 30 minutes a day, can increase metabolic rate, reduce blood pressure, improve cholesterol levels, tone muscles, improve flexibility, and even improve cardiovascular fitness – enough to reduce the risk of heart disease and type-2 diabetes. Gardening, including raking, burns between 265-415 calories per hour, depending on the level of activity (pushing a hand-mower or raking leaves will be more strenuous than light weeding; for comparison, jogging burns about 430 calories per hour). And that’s just the physical exercise. The psychological benefits of working outdoors are myriad (and, of course, they’re all connected anyway). Many horticultural therapy programs include raking; it’s something most of us have done at some point in our lives, and often brings back fond memories – in addition to the physical activity, the smell and sound of leaves is very evocative and can trigger positive memories and feelings – which is particularly important for people with dementia.

And if all that isn’t enough to make you want to grab a rake and go to it, remember that the old-school way of dealing with leaves is a lot better for the environment than standing behind a leaf-blower, using expensive gasoline, inhaling fumes and going deaf while enraging all of your neighbors in the process.
As with all garden work, take care not to overdo it by lifting too much, working more than you feel up to, or exposing yourself to the elements (sun, heat, wind, cold) for too long. The Martha Stewart Living article (link above) is chock-full of good information, including pointers on lessening the risk of strain or injury while you’re getting that good garden work-out.

Therapeutic Landscapes Research Initiative (TLRI)

Image courtesy Henry Domke Fine Art
People interested in evidence-based landscape design are usually underwhelmed by the amount of solid research out there. It’s hard to design a garden for, say, people with schizophrenia, when so little research has been done on this specific population. Or as another example, sure, we all know by now that people prefer lots of greenery to spaces that don’t have much plant material. But what kinds of plant material do they prefer? What colors, shapes, textures, forms? The study below discusses preferred tree forms. So although often we don’t have enough information, sometimes we can be overwhelmed by what has been published. Of the research that exists, how do we tease out what’s the newest, the most valid, the most pertinent to our specific project?

The Therapeutic Landscapes Research Initiative (TLRI) was launched as a way to try to answer these questions and fill some of the gaps. After all, designers and people in health and human services don’t have much time for research. They want answers quickly, and the more current and germane to their project, the better. Funded by ASLA and spearheaded by several ASLA Healthcare and Therapeutic Design Professional Practice Network members, the TLRI is an excellent resource. Students at Iowa State have compiled a list of the most current and relevant articles from over twenty journals and other publications, with synopses of each study that really help give a sense of what the research is about.

Here’s the link to the site: http://www.asla.org/ContentDetail.aspx?id=20272

And here’s one example:

“Responses to Scenes with Spreading, Rounded, and Conical Tree Forms.” 


This study sought to understand reactions and preferences of 206 participants to different types of tree forms. It was predicted that people would have a preference for the savanna-like spreading form. Participants viewed slides of trees that were digitally enhanced to emphasize the conical, spreading, and rounded tree forms. Measurement tools included preference questions, affective responses, skin temperature, and blood pressure. Results revealed that the spreading form was preferred over rounded and conical forms. It was also important that any tree form was preferred over inanimate objects in an urban setting. Trees, regardless of their shape or canopy density, are essential in urban environments for the well-being of the residents.” Environment and Behavior, 12/20/2007, 5 667-688.


Sustainable Sites Initiative draft open for public comment

Image courtesy Sustainable Sites Initiative

If you haven’t yet checked out the Sustainable Sites Initiative, the website is worth a look. Note the Human Health & Well-being component of their mission. They’ve recently released a draft of their latest Guidelines and Performance Benchmarks, and are seeking public comment. Here’s your opportunity to weigh in. See below for more details:

The Sustainable Sites Initiative invites public comment on the new report titled Guidelines and Performance Benchmarks Draft 2008, the most comprehensive set of national guidelines yet developed for the sustainable design, construction and maintenance of landscapes. The report is available for download at www.sustainablesites.org, and an online feedback form has been created for users to help improve the guidelines.

These guidelines will enable built landscapes to support natural ecological functions by protecting existing ecosystems and regenerating ecological capacity where it has been lost. The report includes more than 50 prerequisites and credit options that cover everything from initial site selection to construction and maintenance. The report represents thousands of hours with input from 37 technical advisors in hydrology, vegetation, soils, materials and human health and well being. These credits were tailored to apply to any landscape, with our without buildings.

New Research Summary from InformeDesign: Promoting Aging in Place


This week’s research summaries from InformeDesign include a study that “analyzed whether community and housing resources supported aging in place in two Iowa communities (urban and rural), and identified factors related to elderly individuals’ decision to make assistive home modifications.” Click HERE to read the full research summary.

The most popular modification was the addition of handrails to stairs and steps; though the summary does not specify whether these modifications occurred indoors or out, the research may shed light on numerous ways that landscape designers can make homes safer and more usable for the elderly, thus enabling them to remain in their homes for a longer period of time. 

Full Citation: Cook, Christine C., Mary H. Yearns, and Peter Martin (2005). “Aging in Place: Home Modifications Among Rural and Urban Elderly.” American Association of Housing Educators: Housing and Society. Vol. 32 (1), pp. 85-106.

New study: Green spaces reduce the health gap between rich and poor

Photo by Henry Domke, Henry Domke Fine Art

Correction! First, there’s a correction in the first paragraph of the last post about the Bloedel Reserve, so if you read it yesterday or earlier today, please take another look (just scroll down).
Now for today’s news: The BBC News article “Green spaces reduce health gap” describes a new study published in The Lancet. The gist: Even small parks and other green spaces in urban areas can reduce the “health gap” between rich and poor, reducing the risk of heart disease, stroke, and other health problems. 

Drs. Richard Mitchell of the University of Glasgow and Frank Popham of the University of St. Andrews (both in Scotland) said: “The implications of this study are clear – environments that promote good health might be crucial in the fight to reduce health inequalities.” Click HERE to link to the full article (“Effect of exposure to natural environment on health inequalities: an observational population study.” The Lancet, Volume 372, Issue 9650, pp. 1655-1660). 

Dr. Terry Hartig of the Institute for Housing and Urban Research at Uppsala University in Sweden commented on the study in the same Lancet issue, which you can read part of (or all of if you register) by clicking HERE. Hartig said: “This study offers valuable evidence that green space does more than ‘pretty up’ the neighbourhood – it appears to have real health effects on health inequality, of a kind that politicians and health authorities should take seriously.”