Indoor Environmental Quality and Sustainability

Indoor air quality (IAQ), thermal comfort, acoustics, lighting and sustainable practices

February 2016 — Good indoor environmental quality (IEQ) is an essential objective for new construction or renovation of any building, especially if the parallel objective is a sustainable building environment. Efforts to create optimal indoor environmental conditions enable owners and managers to anticipate and avoid negative health effects, liability related to the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), bad publicity, and costly renovations and repairs often associated with IEQ problems. Efforts to improve IEQ involve planning, designing, building, operating, maintaining, and renovating buildings in ways that reduce pollution sources and remove indoor pollutants.

Sustainable practices impact IEQ in a variety of ways, including buying and using cleaning and maintenance products; selecting building materials and furnishings that are manufactured with less toxic materials; and designing for more and better light. Sustainable practices are intended to conserve resources that benefit human life and health and discourage the use of substances and materials that waste resources, cannot renew themselves (as “natural” resources such as wood can), contaminate air and water, and generally impair quality of life over the long term. For the building or facilities manager, sustainability requires careful judgment in the selection of paints, solvents, sealants, and cleaning products, which often contain volatile organic compounds (VOCs). The harm inherent in airborne or off-gassed VOCs is well established, as are the negative effects of corrosive, carcinogenic, and irritating chemicals commonly used in industry.

Choosing less hazardous products minimizes harmful impacts to workers, improves indoor air quality (IAQ), and reduces water pollution. With many competing claims to consider, finding and purchasing environmentally friendly products and services can be a challenge. However, several reputable organizations have developed third-party certifications to streamline the process. Green Seal, for example, is an independent organization that tests and certifies products and services that protect IEQ and maintain performance standards.

Sustainability and IEQ intersect in construction practices, particularly those covered in rating system guidelines such as the BOMA 360 Performance Program and Leadership in Energy & Environmental Design (LEED). The EPA defines green or sustainable construction as “the practice of creating and using healthier and more resource-efficient models of construction, renovation, operation, maintenance, and demolition.” Research and experience increasingly demonstrate that when buildings are designed and operated with lifecycle impacts in mind, they contribute to all three aspects of the triple bottom line (3BL)—social, environmental, and economic.

Managers are increasingly focused on making their buildings sustainable and more efficient by using healthier, less polluting, and more resource-efficient practices. At the same time, buildings are being renovated or built with a view to lowering operating costs and achieving higher worker productivity. These two aspects of the 3BL—environmental and economic—are often achieved using the same strategies. Some examples of IEQ improvement that can contribute to environmental and economic goals are:

  • improved use of natural light
  • building orientation to maximize use of sunlight and natural winds
  • selection of building materials and furnishings free of formaldehyde and other VOCs
  • greater and more strategic use of live plants indoors and accessibility to nature outdoors
  • full-building air flushing before occupancy to ensure systems are clean
  • building automation systems (BAS) that manage the balance of indoor and outdoor air
  • elimination of toxic indoor and outdoor pest control procedures
  • use of fewer, less toxic landscaping chemicals and fertilizers

Sometimes sustainable solutions for IEQ are high-tech. The US Embassy in Sofia, Bulgaria, has made sophisticated use of advanced filters, humidity control, and carbon dioxide (CO2) monitoring and has included separate ventilation for rooms with high chemical emissions.


IEQ is the consideration of all impacts the indoor environment has on human health and performance, including air quality, thermal comfort, acoustics, and lighting quality.

The terms IEQ and IAQ are often used in conjunction with one another. While addressing similar concerns, IEQ expands the focus of the impact of the indoor environment on building occupants to include acoustics and other factors that can directly affect them. According to the EPA, IAQ refers to “the quality of the air inside buildings as represented by concentrations of pollutants and thermal (temperature and relative humidity) conditions that affect the health, comfort, and performance of occupants.” This definition emphasizes that the determination of good or poor IEQ depends on subjective criteria surrounding occupant perception and performance. The general consensus is that acceptable IEQ exists where 80 percent or more of the occupants rate a space “acceptable,” and 20 percent or fewer rate the space “unacceptable.”

IEQ Impact on Health, Comfort, and Performance of Building Occupants

A conclusive link between the quality of the indoor environment and occupant productivity has the potential to dramatically change the way buildings operate in the future. Improvements to the indoor environment that result in a one percent productivity improvement could be the financial equivalent of cutting energy use by 100 percent or more on an annual basis.

The quality of the indoor environment affects the health, comfort, and performance of building occupants. While building operating costs associated with energy receive considerable attention, salaries and employment costs associated with building occupants are often 100 times the annual energy costs.

Although the potential is high, there are structural hurdles in accounting for this productivity benefit and its associated costs. When looking to improve energy performance, the first step is to measure—to benchmark current usage against an industry standard. Productivity, however, is more difficult to break down into a specific set of data points. Instead, targeting factors that directly impact productivity can produce more immediately measurable results.

Studies have confirmed a correlation between IEQ improvements and increased worker productivity. Productivity measures included an analysis of data entry by office workers using software that tracked correct keystrokes, errors, and mouse activity. Recognizing that IEQ affects occupant performance is one aspect of operating a high-performance building. Poor IEQ can lead to medical and even legal costs. Acceptable IEQ can not only avoid those costs, but also assist in leasing and maintaining a high level of occupancy.

To address IEQ issues, it is vital that IEQ evaluation and maintenance are integrated within existing tools and processes for building operations. This includes building systems that directly influence IEQ status, the assessment of IEQ, and opportunities for enhancing and resolving IEQ issues.

This article is adapted from BOMI International’s course High-Performance Sustainable Building Principles, part of the RPA|HP and FMA|HP enhanced designation programs. More information regarding this course or the new High-Performance certificate courses is available by calling 1-800-235-2664. Visit BOMI International’s website,