COMMUNICATE THE BENEFITS OF DAYLIGHTING

By Adam Mitchell; marketing manager at AGNORA

Daylighting is an important, well-studied and well-documented subject, but this widely accepted term is still nuanced for most. Daylighting is a term used to describe glazed areas, building orientation, light reflection/transmission values, and reflective surfaces designed to distribute light in buildings interior.

Architectural glass, and its relation to daylighting, faces communication challenges across stakeholder groups within the building industry. To address these challenges, we as the glass industry can use the enormous body of knowledge regarding daylighting to model common benefits to building designers and owners. We can demonstrate how modern architectural glass products can be used to incorporate these benefits.

1. Health – There have been several studies outlining the improvement of health from increased daylight. A key finding is increasing daylight in a built environment is known to increase an individual’s amount of sleep. Getting proper amounts of sleep decreases cortisol (the stress hormone), increases glucose metabolism and decreases appetite. This leads to less stress, lower blood pressure and controlled weight. The merits of natural light are also attributed to a reduced length of stay in health care environments, indicating the body’s reliance on light’s healing properties, according to the 2018 study, “The Effects of Natural Daylight on Length of Hospital Stay.”
2. Productivity – It is well accepted that daylighting improves productivity, and often studies draw similar conclusions: productivity goes up. The 2002 study, “Effects of Natural Light on Building Occupants,” found that professionals (engineers) working in a predominantly daylit space increased output by 13 percent and decreased absenteeism by 15 percent. Light is the primary mode for humans to ingest information; consequently, it’s no wonder natural light improves these outcomes.
3. Cost improvements – These increased output and absenteeism rates are eye-opening and impact organizations the larger they are. According to Small Business Trends, the average U.S. business employs 10 people. Assume the business sees an increased output of a conservative 10 percent (versus 13 percent). This is equivalent to an hourly surplus of 2,940 working hours per year.

Further, daylighting greatly reduces reliance on artificial lights. As there are many factors it is difficult to quantify a savings value, but one such study, “Daylighting: An alternative approach to lighting buildings,” assumed a saving of 20 Watt/m2 for the particular environment, saving an average of 2160 MWh per year based on a specific 430,000-square-foot (40,000 m2) building.

Glass is the only facade material that allows for daylighting; thus, it is vitally important to connect the technical attributes with the benefits in a clear and concise message to partners responsible for contemporary building design and construction. As an industry, we should not only address the incredible performance characteristics of today’s glass, but also attach it to the value it provides.

Factoring windows into the design of a new building does not add much in terms of the design budget, but the long-term productivity and energy reduction benefits far exceed incremental design costs. Windows are the gateway to better environments and innovations in anti-reflective technology combined with high-performance coatings can provide improved daylighting to a space.

THE IMPORTANCE OF DESIGNING FOR OUR (UN)NATURAL HABITAT

By Lisa Heschong

Editor’s Note: The following is an excerpt from Heschong’s book, “Visual Delight in Architecture,” available through Routledge.

We modern humans spend over 90 percent of our lives inside of buildings. […] Since we now spend most of our lives inside of buildings, it matters a great deal how those buildings are designed. The indoor environment is now our (un)natural habitat! The forms, details, and functions of buildings profoundly impact our physical health and mental well-being, they set the stage for how we perceive the environment around us, they influence our social relationships, and they both form and inform our culture.

Humans are highly visual creatures. Whereas dogs understand their world largely through their sense of smell, and creatures with exceptionally large ears or long whiskers may rely more on sound or touch, we humans use our sense of sight as our primary mode for understanding the world. In many ways, due to the very evolutionary perfection of our eyes, our interaction with the visual environment is often so seamless, so very easy, that it does not demand much thought or reflection. But the design of our buildings importantly determines the visual environment in which we spend our lives. […]

I first realized that I needed to write this book when I was working with a team of colleagues on a proposal that one of our national ‘green’ building codes should require at least 50 percent of all workspaces to have access to a view of the outdoors. We called it our ‘view proposal.’

My team had already succeeded in persuading this same code group to adopt minimum requirements for daylight illumination, which they considered to be a reasonable expression of best practices. I knew from my experience that, a decade or two earlier, general building industry attitudes had been strongly arrayed against daylight illumination. As a design architect, I had struggled to get daylighting design included in the schools and office buildings I was working on. However, in 1999, I completed a major research study, which showed that elementary school children in classrooms with more daylight progressed faster on their math and reading curriculum. The study’s findings quickly made national and international headlines, and soon ‘natural daylight’ became a preferred feature for high-performance school design. In the years since, many other researchers’ findings have supported the positive effects of daylight, and other codes and standards groups had already moved to adopt minimum daylighting requirements. Thus, after decades of effort by many people to persuade the building industry to embrace daylight illumination, a sea change in attitudes had indeed happened.

However, the national code committee’s reaction to our view proposal was very different. After many long discussions, it was soundly voted down by over 70 percent of the committee! The most succinct statement of the opposition that I received was that “a view requirement is not appropriate for a green building code because it has no health or environmental impacts: views are an amenity.” An amenity is a real estate term for something for which you must pay extra. Fresh air used to be considered an amenity, back in the days when industrial air pollution was pervasive in our cities. Now it is recognized as fundamental to human health. I realized we had a long way to go to persuade these code officials, the building industry, and the public at large, that access to views mattered, at least as much as daylight illumination and maybe more so. It can take a long time to change widespread attitudes and assumptions.

WHAT’S STANDING IN THE WAY OF DAYLIGHTING AND VIEWS?

By Helen Sanders; leader in strategic business development for Technoform.

1. Education gaps. Changing business-as-usual practices is a challenge. In the design industry, it requires educating the full project team. However, there are over 100,000 architects and additionally, owners, who need to be educated on the impacts of daylight and views. Have we reached all of them with the depth and breadth of the information, or are we “preaching to a smaller choir” and not reaching the majority of architects who need to understand the negative consequences of not designing for occupant health?
2. Good design is neither cheap nor easy. We run into the issues of designing good day-lit spaces. The tools to assess daylight availability and glare using metrics such as spatial daylight autonomy, daylight glare potential, useful daylight illuminance, etc., are available, but they are complex to use and the solutions to creating good day-lit spaces may be difficult or costly to achieve, especially if not considered at the very outset of the design process, and in the context of meeting other design goals. Getting a daylighting professional in early in the design process has historically been a challenge. It is too late to make much of an impact when designers are brought in late into the process.
Consider as an example the uptake in the daylight and views credit in the LEED certification program. Only 31 percent of LEED certified projects achieved a daylight credit in LEEDv4, so the criteria have been changed in version 4.1 to try to make it more attractive for projects to focus on. This all leads us to the fact that it costs more to hire a daylighting designer and do the appropriate analysis than to continue with the status quo. Having a daylighting designer at the table (along with other key competencies for considering thermal comfort and air quality) at the design phase is not yet business-as-usual, but needs to become that if we are to create human-centered, sustainable buildings. think we also have many uncomfortable, overly day-lit spaces that have plenty of view fenestration and daylight, but where large expanses of curtain wall are used, and thermal comfort and glare control are not adequately considered. This gives glass curtain wall a bad reputation and leads to conversations about limiting glass areas.
3. Financial payback. We need to do a better job of communicating the payback in hard dollars and cents to building owners. The payback on these design strategies is not immediately accessible, unlike for energy, and can require owners to take a leap of faith.
Getting the results of the research (real applied research in real buildings on real people) and impact on their bottom line to building owners (and their business tenants) seems key since they are going to be making the decisions on design and budget and setting the design intent. If all building owners came to architects and said, “I want a thermally comfortable, well daylit building, with views to nature through windows, and good ventilation to provide appropriate air quality for 100 percent of the occupants of my building” as a starting point for the design requirement, then we would have different outcomes. (We also have the split incentive in speculative real estate where the owner doesn’t accrue the “health and productivity” benefits of a good/more expensive design.)
4. The real versus simulated debate. We need to be clear about the differences between real and artificial daylight and views. The lighting industry has done a great job of selling its circadian lighting and likely gives the impression that it can replace actual daylight for the entrainment of human circadian rhythms. Data needs to be brought to the fore to demonstrate real is best, and that circadian lighting may be better than nothing, but not sufficient to replace the benefit of exposure to the much higher intensity of real daylight. Additionally, what if the power goes out? What about all the other safety issues?