Mathias Wambsganß: "The elderly and sick are part of a vulnerable group—what do we do for them?"

Katinka Corts
2. luglio 2024
Mathias Wambsganß studied architecture and is now a consultant engineer for the Bavarian Chamber of Engineers, lighting designer and lecturer. (Photo: 3lpi)
Before we start talking specifically about hospital design: What do you consider to be healthy and, depending on requirements, stimulating or calming lighting design with regard to daylight?

Daylight is the best light source of all, and lighting planning must start with it. It is dramatic when, as a planner, you join a project and realize that had you been involved earlier, much could have been improved in terms of daylight. Daylight is a dynamic light source, but we can modulate it to some extent. For me, good daylight planning is one that can respond to this dynamic. 

When I say ‘respond’, I don’t mean using static solar control glazing! This may help get you through the hottest six weeks of the year, but it also means a poorer transmission rate in the remaining 46 weeks. In addition, I am voluntarily depriving myself not only of part of the daylight quantity but also of its spectral quality. 

The use of large amounts of glass in the façade does not automatically ensure good supply of daylight, as a lot of glass can also cause a lot of problems. Good façade design can thus prevent an excess of light. We must therefore learn to place openings judiciously: in the right places, with the best possible glass. And by “best possible”, I do not only mean in terms of thermal building physics. 

Development of sleep behavior: From birth to old age: sleep and wake phases during the day change over the years. (Graphic: licht.de)
Circadian lighting: Daylight-like lighting with non-visual effects is only useful during the day (blue curve). At night, in the evening and early morning hours, biologically less effective light is appropriate. This prevents disruption of biological processes in the body, such as the evening increase in the hormone melatonin (orange). (Graphic: licht.de)
Which of these factors would you consider to be particularly critical in hospital and care contexts?

The boundary conditions are the same everywhere, but there is differentiation. In hospital construction, there are, to put it bluntly, two classes of patients: those close to the windows and those far from the windows. Studies have shown that patients with more daylight exposure are discharged faster. Nevertheless, patient rooms in modern hospital buildings are generally oriented toward the light. In hospitals, my concern is more about the staff, who work there 24/7, especially those working in shifts. 

I’ll give you an example: We are currently working on a project for an emergency room. When a patient arrives here, decisions have to be made quickly, regardless of the time of day. Nevertheless, these areas should not be operated in full brightness at all times, because in normal operation, the staff needs to be protected from excessive blue light components in the evening and at night, which have a negative impact on the circadian rhythm1.

"We humans are made for living outdoors but spend a lot of time indoors. At the same time, we have been growing significantly older within a relatively short period of time in terms of evolutionary biology due to our access to good food and medicine. However, the parts of our bodies wear out over the years. This includes the accumulation of deposits in the vitreous body of the eye, which affects our vision and ability to absorb light."

Mathias Wambsganß

'The right light at the right time' is what I automatically think of when I hear your words. However, the daily routine of patients in hospital is rather passive and subject to external factors, such as wake-up, eating or sleeping times. This has little to do with their own healthy rhythm. How could lighting and daylight planning support people in this regard?

Taking this into account must be part of everyday planning today. We can easily plan specific concepts today, and it hardly costs any more money. I see this issue more as a problem of willingness and ‘clever implementation’. For example, in a patient room, if someone comes in at night to check on things, a different light should come on than during the day or in critical situations requiring full lighting. This way, we can better meet the needs of patients, at least in this area, although we cannot influence the necessary time schedules of hospitals. 

Patient room with transparent acrylic glass sphere, REHAB Basel. Architecture: Herzog & de Meuron (Photo: © Margherita Spiluttini)
Sleep disorders and sometimes associated depression due to declining melatonin levels 2 are a problem for many people as they age. In hospitals and care facilities, this makes it difficult for older patients to stay in unfamiliar surroundings. Could targeted exposure to daylight during the day and, if necessary, luminous ceilings help alleviate this?

Studies show a possible positive influence of (day)light on people with sleep problems or the mentioned depression. The first step is to make good use of the available daylight. Particularly in the morning, a biological window opens during which we are especially receptive to larger amounts of light with blue components. This morning activation also positively affects our sleep quality the following night. For healthy people, this means: don’t buy an expensive lamp, but spend at least half an hour outside in the morning. 

However, the elderly and sick are part of a vulnerable group that may no longer be able to do this—what do we do for them? In the planning, we can ensure that the main areas where the affected individuals spend time are as close to the façade as possible. If there is not enough daylight on dark days, artificial lighting can provide the needed light. Several factors need to be consider here, such as the fact that extensive luminous surfaces have a greater effect than small, more selected small light sources, even if the amount of light reaching the eye is comparable. All in all, it is not enough to just select a luminaire; the rooms need to be planned holistically, including the materials used for the surfaces enclosing them. 

We can strengthen the circadian rhythm through these measures, but we must also realize that the requirements to achieve this are higher for older people. The lenses in the eyes become cloudy and yellowish with age, a process that significantly changes color perception and sensitivity to glare. The pupil diameter also decreases with increasing age, and for some older people, activation by light is no longer possible. 

A successful combination of daylight and artificial light makes the patient room appear more homely. University Hospital Cologne, private room on an ENT ward. Interior design: 100 % Interior, manufacturer of medical supply unit: Schyns Medizinaltechnik (Photo: Karin Hessmann)
Isn’t it difficult to find solutions that work for everyone? For instance, someone living in a nursing home who is visited by younger relatives might sit down somewhere for coffee and cake. While young people will likely sit by the window or on the terrace, the elderly might find these areas too bright. So, how do you plan spaces when the needs of some are completely different to those of others?

This is precisely where we encounter a conflict of objectives: The planner who only considers non-visual effects wants to stimulate circadian synchronization for elderly people. This involves a higher amount of light in the morning hours. However, if I assess the scene visually, I know that this amount of light is suitable for tasks like knitting or solving crosswords. If the entire room is this bright and the surfaces reflect the light strongly, it can quickly lead to irritation and glare. Lighting design must therefore take into account both non-visual effects and perception-based issues. Where are the important visual tasks, and how can we minimize the risk of glare? 

A central task in room planning therefore is to analyze where people sit or lie in hospitals and what are their sightlines. If rooms are illuminate from above, this is ideal for staff, but someone who lies down a lot may be constantly blinded. The industry provides us with wonderful lighting tools, but above all we need lighting designers who know how to use them correctly.

"We have a long evolutionary history, and the transition from a society living outdoors to one living indoors has been extremely short, spanning only 10 to 15 generations. From an evolutionary biology perspective, this is not enough time for our bodies to adapt to the significantly reduced exposure to radiation."

Mathias Wambsganß

At the Neues Marthastift in Basel, circadian-adapted lighting helps regulate the residents’ melatonin levels. Architecture: Müller & Naegelin Architekten BSA, Ateliergemeinschaft Basel (Photo: Leonardo Finotti)
At conferences on the topic of light in particular, I notice that there is a tremendous amount of knowledge on the part of researchers, such as human biologists, and that lighting designers also have a great deal of knowledge in a different area. At the same time, a lot of content is lost in the knowledge transfer between these areas. How can we ensure that, despite the fast pace of change, key messages from research reach lighting designers, architects and ultimately the clients?

Let’s start with the latter. It is true that for planning to be successful, clients need to understand the relevance of the topic. Only then, there is a shared interest in addressing the aspect of ‘light and health’ equally with other requirements. This can generally be achieved through broader dissemination of knowledge to the general population, as well as through embedding planning recommendations or guidelines in relevant regulations. Initial steps have already been taken and more will follow. For those already actively involved in planning, further training on the topic is a good idea, and for students in various relevant disciplines, this knowledge must be part of their education. In the four different degree programs I teach at TH Rosenheim, the topic of ‘light and health’ is, of course, an important component.

Patient room at the ‘AZ Zeno’ in Knokke-Heist, Belgium. Architecture: B2Ai (Photo: © Tarkett/Tim Fisher & Milosz Siebert)
What do you wish for the future of lighting design?

First and foremost, I wish for more awareness of the value of daylight. We typically discuss the U-value and g-value of transparent building components, both of which are also included in regulations for thermal protection in summer and winter. The transmission of the light spectrum, on the other hand, is nowhere to be found. It is, so to speak, the ‘byproduct’ once the calculations for thermal building physics are completed. And that is unfortunate, as there is an imbalance. It is important to me that the topic of light is discussed in planning tasks already in the early planning phase. That we think together about the building’s shape and discuss which rooms need which type of façade and how the right amount of daylight reaches the rooms and users at the right time. This is followed by consistent planning of artificial lighting that is based on design, ergonomics and also non-visual requirements, weighted differently depending on the task. This is my wish, and not just for hospitals or care facilities, but for all types of buildings.

After studying architecture at TH Karlsruhe (now KIT), Mathias Wambsganß was a founding partner of ip5 – ingenieurpartnerschaft (1999–2016) in Karlsruhe. In 2014, he founded the office 3lpi lichtplaner + beratende ingenieure in Munich. Since 2007, Wambsganß has been teaching Lighting Planning and Building Technology at TH Rosenheim, is a member of the board of Deutsche Gesellschaft für Lichttechnik und Lichtgestaltung e. V. (LiTG, German Society for Lighting Technology and Design) and chairs the Technical-Scientific Committee (TWA) of LiTG.
 
This article is part of the special feature Healing Architecture, where we discuss with important national and international experts the criteria for creating a high quality of stay in healthcare buildings. We also present healthcare buildings where this aspect is already highly valued. Previously published articles in this series include:


– The Path to a Better Quality of Stay in Hospitals: Economic Aspects of Hospital Planning
 
– Designing Healing Spaces: Focus Europe

– Mastering Global Challenges with Hospital Architecture 

– Digitization in the Healthcare Sector

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