We spend approximately 90% of our time indoors 1, making the quality of these spaces crucial to our health, well-being, and productivity. Green building certifications have emerged as a valuable tool to ensure that buildings are designed, constructed, and operated in a way that promotes occupant health and minimizes environmental impact. This report explores the link between green building certifications and occupant health, with a particular focus on the impact of indoor environmental quality (IEQ) on productivity and well-being.
To gather the information presented in this report, a comprehensive research process was conducted. This involved exploring research papers and articles on the impact of IEQ on productivity and well-being, examining green building certifications and their requirements, analyzing case studies of buildings with green certifications, and investigating specific aspects of IEQ and their effects on health and productivity. Finally, recommendations for improving IEQ in buildings were gathered from authoritative sources.
Indoor environmental quality (IEQ) encompasses various factors, including air quality, thermal comfort, lighting, and acoustics, that can significantly influence the health and well-being of building occupants 2. Studies have shown a strong correlation between IEQ and occupant satisfaction, health, and productivity 4.
Air quality is a critical component of IEQ, as it directly affects our respiratory health and cognitive function. Poor indoor air quality can lead to a range of health issues, including respiratory problems, allergies, and even more severe conditions like lung cancer 3. Pollutants such as volatile organic compounds (VOCs), particulate matter, and carbon dioxide can accumulate indoors due to inadequate ventilation, off-gassing from building materials, and occupant activities. These pollutants can cause discomfort, fatigue, and reduced cognitive function, ultimately impacting productivity 3.
Studies have shown that removing common indoor pollution sources or increasing the outdoor air supply can significantly increase office work performance by 6-9% 5. Furthermore, a study by Harvard University found that employees showed lower cognitive function when indoor air quality was poor, taking longer to perform daily tasks and experiencing difficulty concentrating 3. Elevated levels of CO2 indoors can also impact decision-making and cognitive performance 1. Improving indoor air quality in buildings has the potential to increase productivity by up to 5% 6.
Maintaining a comfortable temperature range is crucial for occupant well-being and productivity. Extreme temperatures can lead to discomfort, stress, and decreased performance. While a temperature range of 20 to 26 °C (68–79 °F) is generally comfortable, the optimal temperature for productivity may vary depending on individual preferences, the type of work being performed, and other environmental factors such as humidity and air movement 6. Moreover, thermal discomfort can exacerbate existing health conditions, such as asthma and respiratory allergies 2.
In addition to temperature, relative humidity plays a significant role in thermal comfort. Relative humidity levels below 20% can cause discomfort through drying of the eyes, mucous membranes, and skin, while levels above 70% may lead to condensation and potential mold growth 7.
Lighting plays a vital role in regulating our circadian rhythm, which affects sleep patterns, mood, and alertness. Exposure to natural light has been linked to improved mood, increased energy levels, and enhanced cognitive function 8. Conversely, insufficient or poorly designed lighting can cause eye strain, headaches, and fatigue, negatively impacting productivity and well-being 8. Poor lighting can also disrupt circadian rhythms, increasing the risk of sleep disorders by 10-15% and contributing to a higher incidence of depression and anxiety symptoms 9.
Excessive noise can be a major source of distraction and stress in indoor environments 10. Noise pollution can interfere with concentration, communication, and cognitive performance, leading to reduced productivity and increased stress levels 2. Conversely, well-designed acoustics can create a more peaceful and productive environment.
Green building certifications, such as LEED (Leadership in Energy and Environmental Design) and WELL, provide frameworks for creating healthier and more sustainable buildings. These certifications address various aspects of IEQ, including air quality, thermal comfort, lighting, and acoustics. Other common green building certifications include the Living Building Challenge and Energy Star 11.
LEED certification is a globally recognized green building rating system that promotes sustainable building practices. It includes several requirements related to IEQ, such as:
WELL certification focuses specifically on the health and well-being of building occupants. It sets performance standards for various IEQ factors, including:
Studies have shown that transitioning to WELL-certified offices from non-WELL-certified offices has a positive impact on occupant satisfaction with the workplace and occupant perceived health, well-being, and productivity 19.
Comparison of LEED and WELL Certifications:
|
IEQ Factor |
LEED Requirements |
WELL Requirements |
|---|---|---|
|
Air Quality |
Use of low-emitting materials to minimize VOCs and other pollutants |
Stringent limits for PM2.5, PM10, and other pollutants |
|
Ventilation |
Ventilation systems meeting ASHRAE Standard 62.1 |
Monitoring of ventilation rates and CO2 levels |
|
Thermal Comfort |
Strategies for maintaining optimal thermal conditions, such as natural ventilation and energy-efficient HVAC systems |
Strategies for providing individual thermal control and minimizing drafts |
|
Lighting |
Promotion of daylighting to reduce reliance on artificial lighting |
Standards for light quality, color temperature, and glare control |
|
Acoustics |
Not explicitly addressed |
Not explicitly addressed |
While both LEED and WELL certifications address IEQ, they have distinct focuses. LEED emphasizes sustainable building practices and environmental performance, while WELL prioritizes the health and well-being of occupants. These certifications can complement each other, with LEED providing a framework for sustainable design and construction, and WELL focusing on the specific needs of occupants 20.
Several studies have investigated the impact of green buildings on occupant health and productivity. A study by the World Green Building Council examined 11 facilities around the globe with one or more green certifications, including LEED, Green Star, and BREEAM 21. The study evaluated health and well-being features that were integrated into the facilities, such as enhanced fresh air ventilation, acoustic privacy, increased daylight penetration, and the use of biophilic design elements. After adding these features, companies found that employee absenteeism was reduced, operating costs were minimized, and employees felt more productive and healthier 21.
Another study investigated the effects of improved IEQ on perceived health and productivity in occupants who moved from conventional to green office buildings 22. The study found that improved IEQ contributed to reductions in perceived absenteeism and work hours affected by asthma, respiratory allergies, depression, and stress, and to self-reported improvements in productivity 22. These findings suggest that green buildings may positively affect public health.
Improving IEQ requires a comprehensive approach that addresses all relevant factors. Here are some recommendations for enhancing IEQ in buildings:
Air Quality:
Thermal Comfort:
Lighting:
Acoustics:
Green building certifications and IEQ are intrinsically linked to occupant health, well-being, and productivity. By adhering to the standards set by these certifications and implementing strategies to improve IEQ, building owners and operators can create healthier, more comfortable, and more productive indoor environments. This not only benefits the occupants but also contributes to environmental sustainability and economic benefits. Green buildings have been shown to reduce operating costs through energy and water efficiency, increase productivity and reduce absenteeism, and enhance property values 21. Prioritizing IEQ and green building practices is essential for creating spaces that support our overall well-being and productivity and contribute to a more sustainable future. Building owners, operators, and occupants should all advocate for and adopt these practices to create healthier and more sustainable built environments.