US Indoor Air Quality Standards: Guidebook for Green & Healthy Buildings


The concepts of green construction and healthy buildings are intimately intertwined.

Since the introduction of Building Research Establishment's Environmental Assessment Method (BREEAM) in 1990, the world’s first rating system for green buildings, standards for green and healthy buildings have only grown in prominence. In 2000, the US Green Building Council introduced the Leadership in Energy and Environmental Design (LEED) assessment to improve built structures’ environmental impact. More recent rating systems go beyond current building practices to promote concepts like net-zero energy usage and designs that mimic natural processes or those that work to improve the natural environment.

While these ratings are largely driven by the need to address climate change and the depletion of natural resources, building occupants must always be a primary concern. That’s why indoor air quality standards are a key component of the most modern rating systems, providing invaluable guidance for how to safeguard the health of occupants in commercial buildings.

That’s where Buildings IOT comes in. With industry-leading expertise in building data and systems integration, we provide secure, forward-thinking building IoT solutions and ongoing support for smart buildings.

Importance of Indoor Air Quality Standards

The impact of clean air on human health cannot be denied. Research shows that air pollution causes one out of every eight premature deaths each year—more than any other environmental factor. And pollution doesn’t just happen outdoors. Indoor air quality is deeply impacted by the surrounding environment, as pollutants infiltrate built structures. These include:

  • carbon monoxide (CO)
  • lead (Pb)
  • nitrogen dioxide (NO₂)
  • ozone (O₃)
  • particulate matter (PM₁₀ and PM₂.₅)
  • sulfur dioxide (SO₂)

The impact on human health largely depends on:

  • contaminant concentration
  • exposure duration
  • rate of intake

Using proper air filtration and ventilation, negative effects from various pollution sources can largely be mitigated or even eliminated.

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Understanding Indoor Air Quality Standards

Green building ratings consider that every building has a direct and indirect impact on the environment throughout its lifecycle, from design to demolition. Sustainable building design must also take into account the impact on a building’s occupants. Modern indoor air quality standards and certifications are designed to minimize airborne threats to human health and ensure buildings are safe spaces to live, work, and play.

With the proliferation of different rating systems, each with its own criteria, knowing which standards to apply can be confusing. Increasingly, however, building owners and facilities managers are pursuing WELL Certification, an evidence-based system that includes a detailed evaluation of indoor air quality.

WELL Building Standard

By combining rigorous indoor air quality standards with a range of other health-related benchmarks, WELL Certification has distinct advantages over other ranking systems for buildings. It sets performance standards that go beyond initial design and support ongoing management practices that advance health and well-being.

The Building Standard looks at:

  • Advanced air purification
  • Air filtration
  • Air flush
  • Antimicrobial activity for surfaces
  • Cleanable environment
  • Combustion minimization
  • Direct source ventilation
  • Displacement ventilation
  • Enhanced material safety
  • Fundamental material safety
  • Healthy entrances
  • Operable windows
  • Outdoor air systems
  • Toxic material reduction
  • Ventilation effectiveness
  • Volatile organic compound (VOC) reduction

To promote safe indoor air quality, it also takes into account:

  • Air infiltration management
  • Air quality monitoring and feedback
  • Air quality standards
  • Cleaning equipment
  • Cleaning protocols
  • Construction pollution management
  • Humidity control
  • Increased ventilation
  • Microbe and mold control
  • Moisture management
  • Pest control
  • Pesticide management
  • Smoking bans

The certification process is based in part on benchmarks drawn from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 62.1-2013 standards. To achieve certification, your building must keep key contaminants below set levels:

  • Carbon dioxide levels: under 800 parts per million
  • Carbon: under 9 parts per million
  • Formaldehyde: under 27 parts per billion
  • Ozone: under 51 parts per billion
  • PM 2.5 (airborne particles with less than 2.5 micrometer diameter): under 15 micrograms per cubic meter
  • PM10 (airborne particles with less than 10 micrometer diameter): under 50 micrograms per cubic meter
  • Radon: under 4 picocuries per liter of air
  • Total volatile organic compounds (VOC): under 500 micrograms per cubic meter
  • Additional limitations regarding asbestos, lead, mercury, and polychlorinated biphenyl (PCB) abatement, along with limitations on mercury levels.

The WELL Building Standard provides flexibility for choosing the features that help a project best meet its goals. Your building can also be recognized for going beyond the minimum, as WELL certification scores rate buildings at these three levels:

  • Silver: requires meeting all preconditions.
  • Gold: requires meeting all preconditions, plus 40% of applicable optimizations.
  • Platinum: requires meeting all preconditions, plus 80% of applicable optimizations.

Challenges for Meeting Indoor Air Quality Standards

Meeting robust indoor air quality standards and achieving certification can be highly desirable. It can also create significant challenges that can cause building owners to question whether they will see a return on their investment. For many, however, pursuing certification is the best choice.


Hiring consultants: Hiring a consultant with expert knowledge of indoor air quality standards can help reduce the costs of your healthy building initiatives. Experienced experts ensure success for your project by proactively addressing the challenges and nuances that are common in the process, preventing you from having to retrofit costly fixes later on.


Initial cost: The long-term reduction of energy costs and lower insurance premiums often justify the upfront cost of system integration and installation of sensors. The ability to ask for higher rents, lower tenant turnover, and the value added to your reputation can also make up for the initial expense.


Maintenance and control of equipment: Advanced equipment and control systems can produce significant savings in terms of energy and other utility costs over the long term, often offsetting the initial investment for maintaining and monitoring the equipment that affects indoor air quality.


Upgrading systems: Building owners can often leverage payroll tax credits, grants, and other government incentives to offset the costs of upgrading systems, including through partnerships with tenants. Local, state, and national entities may be able to help building owners shoulder the cost of upgrading their systems.


Ventilation and filtration: Inadequate filtering of contaminants can compromise human health, reduce productivity, and even have legal consequences. Investing in the right sensors and filtration devices for your ventilation systems, and having a service agreement in place with a reliable contractor who can keep those filters clean will mean fewer headaches—literally and figuratively—and protect you from legal liability.

The fact is, meeting indoor air quality standards is an investment that can contribute to long-term savings and value-add opportunities for property owners.

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How Buildings IOT Can Support Healthier Buildings

Buildings IOT can help building owners meet indoor air quality standards using state-of-the-art products and services. These can include installation of indoor air quality sensors to monitor for contaminants and integration of ventilation systems into a central building automation system to better control factors that can lead to unsafe conditions. But perhaps the most important element that Buildings IOT can add is the ability to identify the exact strategies you need to hit your indoor air quality targets.


Skipping Certification

Covid-19 has brought indoor air quality into focus like never before. Yet certification is not necessary to achieve good air quality, and existing buildings often do not need major renovation to make them healthier. More focused measures supported by intelligent and integrated building automation systems can help you identify where to make improvements that enhance indoor air quality without the costs associated with certification. Many factors associated with occupant health can be identified and controlled with the help of agencies such as the EPA or the Consumer Product Safety Commission, both of which offer tips on how to improve air quality indoors. The experts at Buildings IOT can also provide the guidance you need to develop targets and monitor progress.



OnPoint is a cutting-edge analytics platform that draws on sensor data to continuously monitor air quality within your building. Through a mobile-first interface, onPoint offers meaningful insights on how to meet indoor air quality standards based on real-time and historical building data. However, onPoint doesn’t just look at air quality; as part of an integrated building automation system, it oversees all connected equipment, devices, and sensors to provide deep visibility into building conditions, helping you streamline maintenance and optimize overall building performance.



BuiltSpace is an innovative janitorial tracking software platform that can play a key role in creating a cleaner and healthier environment for building occupants. Using QR codes, cleaning crews confirm when cleaning and maintenance tasks have been completed. The data is automatically uploaded to the BuiltSpace mobile app, ensuring stakeholders have the data they need to identify problem areas.

Buildings IOT can help you meet indoor air quality standards and make built environments healthier.