When it comes to moths, the scientific evidence is very clear: moths are attracted to light and tend to fly towards a source of light (such as the moon), especially when in danger. But what about humans and their relationship with light – specifically, their attraction to daylight? Intuitively, most of us would agree that daylight is important to us and therefore must also matter in the workplace. Over the years, researchers have studied daylight in the workplace and how it affects human behaviour, performance and ultimately productivity. However, when you start digging deeper, you find surprisingly little empirical proof of the positive effects of daylight on workers. So is this all just a myth? Or are we, like moths with the moon, attracted to natural light, searching for it and happier when we find it? We were curious to find out.
Daylight has a deep connection to our daily rhythms as human beings. Light controls our circadian rhythm, the 24-hour cycle also known as the internal body clock. The 2017 Nobel Prize for medicine was awarded to researchers who discovered the underlying mechanisms of maintaining circadian activity in every cell. Generally speaking, daylight suppresses the secretion of the hormone melatonin, which induces sleep, hence light governs wakefulness. In addition, the ultraviolet wavelengths in daylight affect the production and synthesis of vitamin D and positively affect the immune system. Therefore, daylight is generally known to impact wellbeing. But how does it matter in workplaces?
To start with, it is important to understand what kind of light we are talking about here, and that is natural daylight coming into the workplace through windows. As opposed to artificial light, natural daylight is brighter and more varied; it allows people to understand seasons and time of day and thus links in with our circadian rhythm. We are not considering what you can see from your office window (which is often called prospect), how large your windows might be, which way they are facing (north or south, east or west), or how distant your desk might be from a source of daylight. While all of these matter in practice, we want to focus on the impact of daylight on the whole (as opposed to working in dimly lit, or just artificially lit workspace).
Research studies suggest that there is a connection between access to daylight and increased employee satisfaction. If asked, humans consistently express explicit preference for natural daylight in offices and cite psychological comfort, health and aesthetics as main reasons. It is also argued that daylight has an impact on productivity, since happy and satisfied employees are also more productive at work. The question remains how significant this impact is and whether it is measurable.
Several case studies from the US seem to have confirmed that there is something in this. A study of Lockheed Martin moving into their new intensively daylit office headquarters for 3,000 staff in Sunnyvale, California in the 1980s reported large increases in productivity based on reducing absenteeism by 15%. A similar case is described in the book ‘Welcome to your world‘ by Sarah Goldhagen. Nine months after moving into a new headquarters in Zeeland, Michigan, furniture manufacturer Herman Miller reported staff productivity had risen by 20%. The building in question was called the ‘Green House’ for its ample use of courtyards, internal gardens and skylights.
Still, productivity at work is often difficult to measure. Therefore, looking into comparable settings with readily defined productivity metrics can be insightful. Here are the most interesting studies we found, showing measurable effects and thus rigorously linking daylight access to increased performance and wellbeing.
- Schools with best daylighting conditions showed up to 26% faster rate of attainment improvement over a one-year period than classrooms with lowest provision of windows.
- Nurses exposed to more than 3 hours of daylight per day reported significantly less work-related stress and higher levels of job satisfaction
- Patients in brighter hospitals units (46% more sunlight) took 22% less painkillers after surgery.
- Workers in workplaces with windows slept 46 minutes longer per night than those without access to natural daylight in their workplace.
So yes, there is robust scientific evidence that natural daylight has an impact on human wellbeing: it eases concentration and learning; raises productivity; reduces stress; and means better and longer sleep at night. Most of these findings however, stem from research in settings other than office-based workplaces, so it will be interesting to see further research in the field, specifically targeted at office buildings, to follow the lead of the study mentioned above on longer sleep at night for those workers having enjoyed daylight during the day.
Many offices in the UK are not designed with daylight in mind. This is partially due to regulations, which recommend daylight in workplaces, but do not demand it. In contrast, other countries regulate daylight access much more rigorously, among them Sweden and Germany. Without regulation, designing in daylight can easily fall down the priority list, especially when the drive for maximising usable space leads to the creation of deep floor plates in many commercial developments.
But the evidence is clear. If you care about the wellbeing and productivity of your office staff, then prioritising access to daylight could be an easy win.