Sustainable Construction and Occupant Health
Designing a sustainable building involves ensuring the well-being of its occupants at every stage, from conception to occupancy. When we know that we spend over 80% of our time in enclosed spaces, the consequences are inevitably alarming.
In this article, we will explore three aspects of sustainable design that directly impact the health and comfort of users: natural lighting, acoustic comfort, indoor air quality, and their roles in environmental certifications.
Natural Lighting and Visual Comfort
Although more challenging in winter, natural lighting should not be overlooked in the design of a project. Natural light has a spectral quality that contributes to comfort, and optimizing it helps reduce energy consumption, even if natural and artificial lighting are interconnected.
The concept of seasonal influence on mood was first introduced in 1987 by the DSM (Diagnostic and Statistical Manual of Mental Disorders) and has been continually studied since. Exposure to light has been shown to increase productivity, with a German study demonstrating a 6% increase in employee activity when moving from 300 to 500 LUX.
In addition to productivity and mood, natural light is beneficial for health, as it allows the body to produce cortisol, also known as the hormone of positive stress, which helps combat stress and anxiety. The design challenge lies in capturing maximum daylight while distributing it appropriately within the building for optimal comfort year-round.
How to Address It?
The strategy for natural light development involves five steps. First, defining an appropriate illumination level (a daylight factor, FLJ) for the intended function of the building. Then, capturing natural light, perhaps by adjusting the building's orientation.
Once captured, light should be distributed throughout the building using interior walls or light distribution devices. Finally, to avoid glare, the placement of sunshades is crucial. Natural lighting can also be complemented with renewable energy sources or optimized artificial lighting to reduce energy consumption.
Music, traffic, construction noise…our environment is filled with various sounds that punctuate our days. However, while noise pollution is the second environmental cause of health problems after air pollution, acoustic comfort is often overlooked in building design.
Acoustics are essential not only for the comfort of occupants but also for their health and well-being. Poor acoustic conditions in buildings can lead to adverse health effects, including increased stress, decreased productivity due to sleep disturbances, and even physical conditions such as hearing loss.
How to Address It?
The use of sound-absorbing materials, such as acoustic ceiling panels, carpets, and wall panels, significantly improves acoustic design. These materials can help reduce reverberation and echo, contributing to a quieter environment.
Indoor Air Quality
In contrast to outdoor air pollution, which is more widely publicized, indoor air pollution remained relatively unknown until the early 2000s. Yet, it is often 2 to 5 times higher than outdoor levels because indoor air is often trapped in enclosed spaces, making it harder to disperse pollutants and leading to the accumulation of pollutants over time. In 2020, indoor air pollution was responsible for about 3.2 million deaths, including over 237,000 deaths of children under 5 years old.
Common sources of indoor air pollution include household cleaning products, pesticides, construction materials, and furniture. Additionally, many modern appliances, such as gas stoves and heaters, can release harmful gasses and particles into the air.
Potential health issues associated with poor indoor air quality are numerous and varied. Respiratory system disorders (rhinitis, bronchitis) are most commonly reported, and it can also contribute to symptoms such as headaches, fatigue, eye irritation, nausea, and, in rarer cases, non-communicable diseases such as stroke or lung cancer.
How to Address It?
Plants can act as non-mechanical air filtration systems that improve indoor air quality in buildings. Additionally, indoor green walls offer building occupants pleasant views that enhance the indoor environment.
The Impact of Certifications
Environmental certification primarily aims to reduce environmental impacts, promote responsible natural resource management, and support biodiversity protection. Beyond environmental goals, these certifications also give significant importance to human health.
LEED (Leadership in Energy and Environmental Design)
LEED and human health are closely linked. The majority of credits in LEED v4 and v5 rating systems address the health of site users, and health-related credits are found in each LEED credit category. These credits include guidelines to improve indoor air quality, promote physical activity, and design for mental health and comfort. For example, integrating an indoor green wall into your projects can earn up to 3 LEED points with the Indoor Environmental Quality credit. Similarly, medical facilities can receive up to 3 additional points for choosing non-toxic materials and furniture to further preserve the health of occupants in LEED-certified buildings.
BREEAM (Building Research Establishment Environmental Assessment Method)
Another environmentally conscious certification is the British BREEAM certification. It emphasizes the impact a building has on the health and well-being of its occupants and visitors. The certification addresses health and well-being in various ways through its set of criteria. While the Health and Well-being category focuses strongly on issues related to indoor environmental quality, other categories also address health and well-being issues, including pollution, ecology and outdoor space, post-construction monitoring, and other aspects related to quality. Recently, BREEAM shared an information *document titled 'Health and Well-being in BREEAM,' highlighting the current consideration of health and well-being issues across different schemes.
HQE (High Environmental Quality)
In France, the HQE certification incorporates health considerations. It includes requirements for acoustic comfort, visual comfort, and olfactory comfort, offering ventilation for the removal of unpleasant odors. Like LEED, HQE also addresses indoor air quality and sanitary conditions, with particular attention to hygiene.