Indoor lighting influences health and well-being

Pooja Shukla

Have you ever wondered if your workplace lighting could be affecting your health?

Light does much more than merely help us see; it has a deep connection with human health and well-being. A well-lit environment can help people work more effectively, improve mood, boost energy levels and positively impact overall physical and emotional health.

GBCI India and Saint Gobain Research India recently released a joint study, Healthy Workplaces for Healthier People, that evaluates the health performance of office buildings in India. The study evaluated 30 offices located in nine cities of India. Building data collected from project teams and professionals who work at the buildings, along with onsite measurements and inspection; and occupant feedback collected through online surveys were all analysed to determine whether the buildings were delivering healthy and comfortable spaces. Important parameters such as indoor air quality, lighting, access to outdoor views, thermal comfort, and acoustics, that define workspace quality, were evaluated.

Access the Workplace Health Study

Poor lighting: a common but hidden problem

64% of the spaces studied had illuminance (lux) levels lower than what is recommended. In some workspaces, the lux levels on workstations were lower than 100 lux, which is one-third of the recommended lux level. In many spaces we found that despite low daylight levels, not all the artificial lights were switched on and occupants continued to work in poor lighting conditions for most of the day without complaint. This indicates the need for better lighting controls and integration of lighting sensors to ensure adequate illuminance in workspaces throughout the day.

Glare and non-uniform lighting were some of the other issues observed in many of the studied workspaces. Despite the poor lighting conditions observed, 76% of occupants reported satisfaction with their office lighting. This highlights that poor lighting is often imperceptible by most occupants and is not getting the attention it merits from building designers and operators.

Improper lighting conditions can cause visual discomfort resulting in issues like eye strain, dry eyes, blurry vision and headaches. Not surprisingly, 60% of the survey respondents reported problems related to their eyes; eye strain was the main complaint reported.

Circadian lighting

Light has a range of non-visual effects on human body functions. It affects the circadian rhythm, which is the body’s internal system that tells us naturally when it is time to wake up in the morning and get sleepy at night. Circadian rhythm controls multiple physiological processes in our body.

‘Equivalent melanopic lux’ (EML) is a metric that characterizes circadian light, or light that acts as a stimulus for the human circadian system. The study findings show that only 10% of offices met the recommended EML level during morning hours.

Daylight has the highest level of light to which the human body’s circadian system is most sensitive; however, we observed that most spaces did not have adequate daylight indoors due to design factors like a deep floor plate, placing meeting rooms and cabins in peripheral areas or high partitions. In offices with manually operated blind systems, it was observed that the practice of occupants using blinds to avoid glare was another reason that led to low daylight penetration indoors. Even though the glare from windows was only for a specific duration, once the blinds were down, they stayed closed for the entire day, greatly reducing daylight penetration inside the space.

Access to external views is important for people’s health and well-being

Access to good quality external views connects occupants to the outdoor natural environment and improves mental health. Nevertheless, study findings show that 74% of occupants surveyed reported no external view or only a poor-quality view from their workstations.

Lack of access to quality views is directly related to how occupants feel at the end of the day and their sleep quality. People who reported having a good view of the outdoors had higher energy levels at the end of the day and reported fewer sleep-related problems than those with poor or no views.

These findings indicate the significant role external views play in determining the overall space quality and enhancing the health and well-being of people.

Careful planning of interior layouts and well-designed windows with appropriate glazing can provide a high-quality lighting environment by maximizing daylight and access to outdoor views. Design for minimizing glare coupled with correct operation of glare control mechanisms ensures that people receive the full benefits of both available daylight and external views.

Read the Healthy Workplaces for Healthier People study to get more information on health performance of workplaces in India, and to learn strategies to ensure occupant health is prioritized in these spaces.

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