Green Buildings, IEQ, and Occupant Health

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.

Impact of Indoor Environmental Quality on Productivity and Well-being

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

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.

Thermal Comfort

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

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.

Acoustics

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 and Indoor Environmental Quality

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

LEED certification is a globally recognized green building rating system that promotes sustainable building practices. It includes several requirements related to IEQ, such as:

• Ventilation: LEED encourages the use of ventilation systems that meet ASHRAE Standard 62.1 for acceptable indoor air quality ¹².
• Air Quality: LEED promotes the use of low-emitting materials to minimize VOCs and other pollutants ¹³.
• Thermal Comfort: LEED encourages strategies for maintaining optimal thermal conditions, such as natural ventilation and energy-efficient HVAC systems ¹⁴.
• Daylighting: LEED promotes the use of daylighting to reduce reliance on artificial lighting and enhance occupant well-being ¹⁵.

WELL Certification

WELL certification focuses specifically on the health and well-being of building occupants. It sets performance standards for various IEQ factors, including:

• Air Quality: WELL sets stringent limits for PM2.5, PM10, and other pollutants ¹⁶.
• Ventilation: WELL requires monitoring of ventilation rates and CO2 levels to ensure adequate fresh air supply ¹³.
• Thermal Comfort: WELL promotes strategies for providing individual thermal control and minimizing drafts ¹⁷.
• Lighting: WELL sets standards for light quality, color temperature, and glare control to promote visual comfort and circadian rhythm regulation ¹⁸.

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:

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.

Case Studies and Research on Green Buildings

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.

Recommendations for Improving Indoor Environmental Quality

Improving IEQ requires a comprehensive approach that addresses all relevant factors. Here are some recommendations for enhancing IEQ in buildings:

Air Quality:

• Ensure adequate ventilation rates and proper maintenance of ventilation systems ²³.
• Use low-emitting materials, implement air filtration strategies, and control sources of indoor pollution ²³.
• Avoid using pesticides and insecticides in the home, as these chemicals can irritate the respiratory system ²⁴.

Thermal Comfort:

• Provide individual thermal control, optimize building envelope design, and use energy-efficient HVAC systems ²⁵.
• Maintain indoor temperatures within the recommended range for different seasons and activities ²⁶.
• Keep relative humidity levels between 40% and 70% to avoid excessive dryness or moisture-related discomfort ²⁶.

Lighting:

• Maximize daylighting, use energy-efficient lighting systems, and implement glare control strategies ¹⁵.

Acoustics:

• Implement sound-absorbing materials, control noise sources, and design spaces to minimize noise transmission ²³.

Conclusion

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.

Works cited

1. How indoor environmental quality impacts health, wellbeing and ..., accessed December 15, 2024, https://www.cundall.com/ideas/blog/how-indoor-environmental-quality-impacts-health-wellbeing-and-productivity-at-work
2. Why good indoor environmental quality can enhance wellbeing ..., accessed December 15, 2024, https://www.britsafe.org/safety-management/2024/why-good-indoor-environmental-quality-can-enhance-wellbeing
3. The Impact of Indoor Air Quality on Employee Productivity - Work ..., accessed December 15, 2024, https://workhealthsolutions.com/docs/the-impact-of-indoor-air-quality-on-employee-productivity/
4. (PDF) Effects of Indoor Environmental Quality on Occupant's Satisfaction, Health and Productivity - ResearchGate, accessed December 15, 2024, https://www.researchgate.net/publication/333698715_Effects_of_Indoor_Environmental_Quality_on_Occupant's_Satisfaction_Health_and_Productivity
5. The effects of indoor air quality on performance and productivity, accessed December 15, 2024, https://pubmed.ncbi.nlm.nih.gov/15330777/
6. Evaluating the Connection between Thermal Comfort and ... - MDPI, accessed December 15, 2024, https://www.mdpi.com/2075-5309/11/6/244
7. Thermal Comfort for Office Work - CCOHS, accessed December 15, 2024, https://www.ccohs.ca/oshanswers/phys_agents/thermal_comfort.html
8. The Impact of Lighting on Employee Productivity and Well-being ..., accessed December 15, 2024, https://www.auralight.com/fi/discover-us/blog/the-impact-of-lighting-on-employee-productivity-and-wellbeing
9. How Lighting Ergonomics Boosts Employee Productivity and ... - BenQ, accessed December 15, 2024, https://www.benq.com/en-us/knowledge-center/knowledge/how-lighting-ergonomics-affects-employee-productivity.html
10. Indoor environmental quality (IEQ) in the home workplace in relation ..., accessed December 15, 2024, https://www.emerald.com/insight/content/doi/10.1108/f-05-2022-0070/full/html
11. Yale Experts Explain Green Building Certifications | Yale Sustainability, accessed December 15, 2024, https://sustainability.yale.edu/explainers/yale-experts-explain-green-building-certifications
12. (Updated Oct 2024) A Detailed Comparison of Indoor Air Quality in ..., accessed December 15, 2024, https://learn.kaiterra.com/en/resources/comparison-of-indoor-air-quality-in-leed-v5-and-leed-v4.1-certification
13. Indoor Air Quality Requirements and Credits in WELL V2, LEED V4 ..., accessed December 15, 2024, https://learn.kaiterra.com/en/resources/indoor-air-quality-requirements-and-credits-in-well-v2-leed-v4-and-reset-air
14. LEED-Certified Homes | Department of Energy, accessed December 15, 2024, https://www.energy.gov/energysaver/leed-certified-homes
15. Indoor Environmental Quality (IEQ) - GSA Sustainable Facilities Tool, accessed December 15, 2024, https://sftool.gov/learn/about/1/indoor-environmental-quality-ieq
16. Well v2 certification: indoor air quality, a key metric - Nuvap, accessed December 15, 2024, https://www.nuvap.com/well-v2-certification-indoor-air-quality-a-key-metric/?lang=en
17. Continuous Air Quality Monitoring for the WELL Building Standard - Atmotube, accessed December 15, 2024, https://atmotube.com/blog/air-quality-monitoring-for-well-certification
18. A01 Air Quality - Standard | WELL V2, accessed December 15, 2024, https://v2.wellcertified.com/en/wellv2/air/feature/7
19. www.nrel.gov, accessed December 15, 2024, https://www.nrel.gov/docs/fy23osti/85534.pdf
20. WELL Certification and LEED Certification for Optimal Indoor Air ..., accessed December 15, 2024, https://airgreeninc.com/news/well-certification-leed-certification-optimal-indoor-air-quality/
21. Doing Right by Planet and People: The Business Case for Health ..., accessed December 15, 2024, https://worldgbc.org/article/doing-right-by-planet-and-people-the-business-case-for-health-and-wellbeing-in-green-building/
22. Effects of Green Buildings on Employee Health and Productivity - PMC, accessed December 15, 2024, https://pmc.ncbi.nlm.nih.gov/articles/PMC2920980/
23. Improving Your Indoor Environment | US EPA, accessed December 15, 2024, https://www.epa.gov/indoor-air-quality-iaq/improving-your-indoor-environment
24. Improving Your Home Indoor Air Quality - ISN, accessed December 15, 2024, https://www.inspectionsupport.com/improving-your-home-indoor-air-quality/
25. CIBSE Top Tips 8: Temperature in Indoor Workplaces (Thermal ..., accessed December 15, 2024, https://www.cibse.org/knowledge-research/knowledge-resources/engineering-guidance/top-tips/cibse-top-tips-8-temperature-in-indoor-workplaces-thermal-comfort-2015
26. How to Achieve Thermal Comfort in Buildings? A Guide to Optimal ..., accessed December 15, 2024, https://www.glazingrefurbishments.co.uk/blog/thermal-comfort-in-buildings