Green Building – A Tool to Improve Employees’ Health and Productivity

Enhancing building ventilation design and adopting green practices may help improve indoor air quality, which will, in turn, lower the risks of mental illness and potentially enhance people’s mental health condition.

People spend around 90,000 hours at the workplace on average over their lifetime. A couple of researches have shown that the design of a workplace has a significant impact on the physical and mental health, well-being and productivity of its users.

Poor mental health induces low productivity and financial loss 

In order to sustain employees’ performance and maintain the efficiency of business operations, companies have invested plenty of resources each year to protect employees’ health. Companies tend to prioritize employees’ physical health over their mental health. For instance, in the UK, only half of the companies had mental health policy[1] in 2017. This is possibly due to the fact that benefits brought about by improving mental health such as a decrease of absentee rates are not as immediate and prominent as physical health.

In fact, psychological health problems are strongly related to employee productivity. Mental health problems can lead to absenteeism as well as presentism, which means showing up to work sick or not operating at a normal level of productivity. In Hong Kong, one-third of employees have faced mental health problems during their employment. Presentism and absenteeism caused by mental health problems could cost Hong Kong employers up to HK$12.4 billion (US$1.58 billion) per year, which is equivalent to 0.5% Hong Kong’s annual GDP[2]. With the rising trend of mental and physical health issues caused by mental problems, the interest and awareness of workplace mental health are emerging simultaneously. Thus, mental health has become the most concerned health need and goal of employees according to the analysis of GRESB Health and Well-being Module: 2016-2018[3]. Employers have to make mental health care one of their top priorities in order to increase employee productivity as well as to attract and retain talents.

How can green building shape a healthier workplace?

Realizing the integral relationship between the indoor environment and the health of employees, green building concepts are a comprehensive strategy to improve the indoor environmental quality such as indoor air quality (IAQ), daylight and thermal comfort through enhancing the efficiency of the building.

Indoor Air Quality (IAQ)

Multiple studies have revealed that air pollutants such as PM10, PM2.5, sulfur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide have a positive relationship with depression, anxiety, and suicide mortality rate[4]. Research indicates that improving air quality may help lower the risks of mental illness and potentially enhance people’s mental health condition. In the case of improving employees’ health and well-being, a company may tackle employees’ mental health issues through enhancing building ventilation design and green practices based on the requirements of certified green building standards.

For example, WELL certification requires all projects to have a proper ventilation system in order to dilute indoor air pollutants. For mechanical or natural ventilation, the design of the system is required to comply with ASHRAE 62.1-2010 or other equivalent standards. Also, the ventilation system is required to be tested and balanced in accordance with ASHRAE 111 or assessed every five years to ensure the ventilation rate complies with the requirement. In addition to ventilation, WELL has other credit requirements on IAQ such as air quality monitoring and air filtration. Employers are advised to make reference to the WELL standard to set up the IAQ management system or pursue WELL certification to maintain decent IAQ.


Apart from indoor air quality, lighting is another critical factor in mental health. Poor lighting can affect employees’ comfort level of fatigue and cause seasonal affective disorder. A study[5] showed that employees who work under poor lighting environment would experience worse sleep quality and result in poor working performance. Poor sleep quality has significant impacts on psychological state and increases the risk of developing particular mental illnesses such as depression and anxiety disorder[6][7]. On the other hand, there is a positive relationship between workplace sunlight exposure and sleep quality of the employees: the exposure of daylight can trigger the release of endorphins which can improve employee moods. Green building designs aim to maximize the penetration of natural light and guarantee the comfort lighting level of the building occupants so as to enhance employees’ sleep quality and mental health state. 

In light of this, Fitwel v2.1, another occupants’ health-oriented building rating system developed by U.S. Centers for Disease Control and Prevention, also has set a credit for daylight and quality views. The credit requires the project to achieve a certain percentage of natural daylight area for a minimum of 51% of all of the regularly occupied spaces such as meeting rooms and workstations. To attain the credit, dynamic glass can manage the sun’s rays while controlling the solar gain of the building. With the assistance of a simulation model, employers can choose suitable dynamic glass to introduce appropriate amounts of natural light and thus enhance employees’ health conditions.

Health and wellness design at current workplace

In response to the public’s concern, some green building standards have put more focus on health and well-being. BEAM Plus, a Hong Kong-based green building labeling scheme, has released BEAM Plus New Buildings Version 2.0, a new assessment tool for new buildings, in September 2019. The new standard introduced a new category of “Health and Well-being” to address occupants’ physical and psychological needs. To cater to the needs of building users pursuing health and wellness, the new standard has stricter requirements on indoor environmental quality and green living design. For example, the registered building has to achieve a good or excellent class in the local IAQ certification scheme instead of compliance with the prescribed limits of air pollutants like carbon monoxide and radon. In the meantime, there is a growing trend towards adopting health and well-being designs at offices and commercial buildings. There are already more than 3,779 projects with over 440 million square feet of floor area participating in WELL certification as of September 2019[8]. The NASDAQ Philadelphia Office is one of the certified projects, which was recognized as a WELL Certified Gold office. The number is expected to rise in the coming years. The updates in green building standards and the rise in WELL certified projects imply that the awareness and materiality of a green and healthy workplace are increasing. Healthier employees are linked to enhanced productivity, retention and higher economic return. It’s time to shape a green and healthy office.  

[1] Shaw-trust(2018), Mental Health at Work: Still the Last Taboo

[4] Hoinston, et. Al. (2019) Ten questions concerning the built environment and mental health

[5]Boubekri, et. al. (2014) Impact of Windows and Daylight Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study

[6] Rezaei (2018) Sleep quality and its association with psychological distress and sleep hygiene: a cross-sectional study among pre-clinical medical students

[7]Harvard Health Publishing(2009) Sleep deprivation can affect your mental health

[8]IWBI(2019) IWBI membership continues to grow

This article was written by Polo Heung, Assistant Consultant at Allied Environmental Consultants Limited