Skip to main content

By Pernille Berg, Science Manager, BLOXHUB


One condition of living in the Nordic hemisphere is to accept the lack of daylight during the winter months. The evenings shorten quickly in the autumn months and always seem to take forever to turn into the infamous bright evenings and nights.

Just as we know of the anecdotal headache syndrome from having poor indoor climate, we also know that those dark months have huge effects on many people.

In preparing for our new series of Science Talks and BLOXHUB Debates we quickly realized that the topic of healthy buildings is more relevant and pertinent than ever. As the pandemic still roars, many people are also spending most of their day indoors. Most likely more than the usual 90% of the day, which is the rule of thumb spent indoors.

But that is not the only reason for the relevance.

Given the increasing knowledge of indoor climate and the detrimental effects of poor indoor climate combined with the paradigm shift in the building industry, namely transforming from delivering a construction to more performance-based success criteria, we quickly realized that the new scientific knowledge should be presented and debated with the various representatives from the industry.

Our series, Healthy Buildings, High Performance, Happy Hearts and Minds, focuses on light, sound, air, space and finally the holistic approach to the topic of healthy buildings.

In preparing for the first Science Talks and Debates I had many discussions with Christina Friis Blach Petersen, Co-founder & CEO at LYS Technologies. The complexity of the science behind light is pervasive.

Formulated colloquially: there is more to light than meets the eye.

I asked Christina, why did you end up creating a company which focuses on light?

Christina answered, “During my studies at Imperial College in London, I was asked by Intel to solve a problem in future urban environments. I was brainstorming late at night in our studio, lit by fluorescent light tubes, and felt the impact of the blue, bright light on me. At the time, I had no previous knowledge of light’s impact on health and it was only when I started delving into the research done in the field of circadian neuroscience, that I felt that some of this knowledge had to be turned into value for people on the street. That’s when I decided to found LYS Technologies.”


Most of us think of the core function of the eye being vision, however, with recent discoveries we now know that the eye has non-visual functions as well.

What researchers are able to document today is our hormonal production of cortisol (ensures we wake up) and melatonin (ensures we fall asleep) depends on the degree of light or lack of light respectively. In our Science Talks with Dr. Manual Spitschan from Oxford University, the huge impact of light on our health was presented. As Manuel Spitschan said, we know the value of bright days and dark nights. What we have also learnt from our research is that lack of bright days has a hugely detrimental impact on our health. Lack of bright days affects our cognitive abilities e.g., reduced ability to concentrate. Lack of light also impacts the probability of depression or mental health in general.

We know the answers to most of the questions of light, but there is still a long way to go before light is a design parameter in architectural calls. Why is that?

Part of this is due to the fact that some of the answers needed are pertinent in the design and construction. We need to know more. For example, the amount of daylight is necessary, what kind of daylight is recommendable and what are the pros and cons of daylight versus artificial light.

Why is it that we design buildings for people, but we install lighting for standards?

Most indoor lighting is directly unhealthy for humans.

Indeed, it seems as if light is seen as a factor which is deemed to be of such low importance that property developers expect it to be as cheap as possible.

When we know that light plays such a vital and significant role when it comes to health, why is it treated less saliently than e.g., air quality and sound?

To this Christina replies that we still need to ensure that more people know about the importance of light. In other words, we need to create awareness at a larger scale. We need public health authorities to focus on this need.

Our core mission at LYS is to help people live healthier with light and we have identified 3 steps to get there. The first step is to create awareness around light’s impact on health and wellbeing through our wearable light sensor and mobile app. The second step is to encourage behaviour change and get people to make the most of natural light through our in-app wellbeing programme. The final step is to integrate with and improve artificial lighting.

We have internalized the need for exercise, many of us know about the 10.000 steps a day as a recommendation. We know, we have to eat our greens. The old saying, an apple a day… still thrives. We know we need to air our homes 3 times a day, 10 minutes each.

But we don’t have a saying when it comes to light! We have not internalized our need for daylight or light in general. Manuel Spitschan “Bright days, dark nights”. Christina says at least 30min of natural light as soon as possible when you wake up, and avoid blue and bright light 2-3 hours before bed.

So, we need to create that focus, we need to increase the level of knowledge. People will not demand light as a decisive parameter when it comes to buildings as we ought to, because we do not have the necessary knowledge to demand it.

During our Science Talks with Dr. Manuel Spitschan this topic also came up. One recommendation from Dr. Spitschan was that we should not focus on cheap light installation; we should rather ensure maximum standards of light.  Indeed, Dr. Manuel Spitschan advocated that public health authorities should focus on creating extensive campaigns on the importance of light.

When Christina Friis Blach Petersen joined the Bloxhub Debates one week after the Science Talks this topic came up again and from that debate, it was quite evident during the debate that the building owners do not focus on light as a special parameter, not until there is a demand-driven need for it. They mostly focus on the visual aspects of light. Having access to daylight or artificial light in buildings so that we can see. However, they are not focused on the health and non-visual aspects of light.

From the debate, we understood that often it is the building owners who want to save cost over-investing in healthy environments.

As one panellist exclaimed during the debate, “light is light.” Merete Madsen, Moe and although we focus so much on healthy buildings today, Merete Madsen emphasized that the light designed and constructed in the 1950s was better than today. In the 1950s there was a greater emphasis on the different personal needs of light given age, activity etc.

And as the debate pointed our given the latest focus on energy-efficient buildings, it seems as if the focus on health has dwindled.

With the current change in creating performance-based indicators, there is hope that the future of light offers much more than the lack of daylight and insufficient work light.

As one of the participating views expressed during the debate:

“I believe we should switch from energy-efficiency to health-improving approach. Talking about lighting, looks like we should make one step back to move forward, looking at daylight and biophilic design.” Dario Maccheroni

Hopefully, the change in demanding buildings performing to maximum standards of health indicators will bring light to the forefront and perhaps even inspire a renaissance of good light design and installations, at home, at work, well, everywhere we go. Because as we know, there is more to light than meets the eye.


Please watch our Science Talks and BLOXHUB Debates on Light

Science Talks:

BLOXHUB Debates: