
Indoor Environmental Quality (IEQ) describes the conditions inside a building, including air quality, lighting, acoustics, and thermal comfort. This guide defines IEQ, why it matters for occupant health and productivity, and how to measure and improve it.
Indoor Environmental Quality (IEQ) is most simply described as the conditions inside of a building. It includes air quality and access to daylight and views, pleasant acoustic conditions, and occupant control over lighting and thermal comfort.
It may also include the functional aspects of the space, such as whether the layout provides easy access to machinery or systems technology and if the occupants can enjoy the area. Read on to learn more about the importance of IEQ and its relation to indoor air quality (IAQ).
Indoor environmental quality (IEQ) is the quality of a building’s overall environment, including the air, lighting, moisture conditions, and the health and well-being of the people inside the space. IEQ relates more strongly to environmental factors that might affect a person’s health. Strongly related to IEQ is sick building syndrome (SBS). With both SBS and poor IEQ, individuals experience health-related symptoms solely when inside the building, and then the symptoms are relieved when they leave the building.
These symptoms might be related to:
Indoor environmental mitigation involves assessment of the space, understanding the pollutant source, and stopping that source. Workers who have been exposed to a specific source of contamination also need to seek medical attention to seek treatment and diagnosis.

IEQ is anything in an indoor environment and might contribute to poor health, poor well-being, and unfavorable living or working conditions. This might include air quality, thermal conditions, ergonomics, and lighting. Improved indoor environments can enhance the occupants in a building, increase the resale of the building, reduce liability, and improve productivity. Here are some familiar sources of poor indoor environmental quality:
By stopping the contaminants at the source, improving HVAC filtration, implementing an air purifier, and making sure to remove or mitigate pollutants in the building, then facility managers (FMs) can comprehensively provide cleaner IEQ. To be effective, the entire building life cycle needs to be considered.

In so many of our blogs, we talk about indoor air quality. Indoor air quality is the state of the air that people are breathing and exposed to. While IAQ is significant to building design and the health of the persons inside the building, it is different from IEQ. Both measures are something that an FM needs to be aware of and regularly test and reassess.
While IEQ and IAQ are strongly related, IEQ has more to do with source management than IAQ. IAQ can come from a range of factors, but they all involve what we are breathing. IEQ might also involve a range of factors, many of them the same as IAQ, but they also pertain to the things we breathe, on top of the things we hear, feel, see, and other physical and psychological aspects indoors.
For example, the feeling of moisture in the air, the indoor air temperature, strange smells, and exposure to sunlight from a window contribute to IEQ. There is some overlap, of course, between these two concepts. Indoor air quality might also be affected by indoor moisture, for example, if the moisture levels get too high and create bacterial or fungal growth. Strange smells might also be the result of a contaminant and contribute to poor IAQ.

Building managers have long held the responsibility of improving the indoor quality for the health and well-being of the persons inside. However, considering the range of sources for poor air quality and discomfort, it’s essential to consider the whole spectrum of indoor comfort. An improved IEQ will contribute to several benefits, including improved health of occupants, improved well-being, and a potential increase in productivity due to fewer symptoms of SBS and poor IAQ. It also accounts for the whole range of occupant experiences.
By addressing the whole range of occupant experiences, FMs will be better equipped to manage poor occupant comfort, sickness, or operational efficiencies. In assessing the environment, FMs can improve the source of air quality, illness, or poor productivity rather than finding Band-aid-like fixes all the time.
IEQ also has an impact on return on investment (ROI). Machinery, infrastructure, and structural upgrades are often cheaper and more cost-effective when maintained. Upgrades can also improve the operational efficiency of the building, occupants, and company. By maintaining the facility, building owners can also seek higher rent and a higher resale.
Businesses can improve the bottom line of the building by improving occupant health and implementing strategies for improved productivity and performance. By minimizing building-related health problems, people will feel better about where they work, and operational efficiency can be excelled. Strategies that align with business and building mandates will find that their employees are more content. The building/company can conserve energy, water, and materials and contribute to a more positive indoor experience.
In terms of the COVID pandemic, it makes much sense to focus on indoor environmental quality. Still, there may be conflict when looking at individual comfort compared to air quality to mitigate airborne pathogens.
Since SARS-CoV-2 is transmitted through airborne droplets and in contacting surfaces contaminated with the SARS-CoV-2, some facility managers will have to focus on cleanliness, increased cleaning times, and optimizing the workplace for managing occupants enforcing enforcement social distancing and ensuring compliance.
Personnel will likely have to wear PPE for an extended duration while indoors, so many of the complaints around discomfort might be ignored for the time being. That said, FMs might find that they are “catching up” on improving the IEQ in space after COVID precautions are considered; in this same vein, not many FMs can focus their roles on individual comfort at this time, right now. This is all the more true considering the time and mental capacity that adjustments due to COVID have taken up.
The current parameters in place to mitigate the COVID pandemic certainly fall under IEQ. However, FMs need to develop facility roadmaps and business contingency/recovery plans that account for continued operations post-COVID and future pandemic disasters. Luckily, many of the FMs are taking to improve air quality for COVID can be used to improve IEQ.

A lot of the government recommendations around IEQ address the building’s sustainability or ability to be “green.” While going green is preferred, it does not necessarily mean that you are always accounting for IEQ effectively. Here are some of the best first steps for addressing IEQ:

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Download our E360 Business Solutions Guide to learn how your business can transform its operations for better energy, operational efficiency, and indoor air quality.
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