What’s new in WELL v2: Air

Why air matters

On average, an adult inhales more than 15,000 liters of air every day. This interaction makes the air we breathe one of the most fundamental environmental determinants of human health. Ambient air pollution is on the rise and in many regions around the world, outdoor air is deemed unsafe to breathe. Threats of ambient air pollution are projected to intensify in response to climate change, especially in rapidly expanding low-income urban settings. The growing imperative to protect human health from poor air quality has resulted in the promotion of clean air as a global priority by the World Health Organization (WHO), United Nations Environment Programme (UNEP), and World Bank among many other global institutions.

Certain ambient air pollutants are particularly troublesome due to their impacts on multiple body systems including the respiratory, nervous and cardiovascular systems. One such pollutant is particulate matter less than 2.5 micrometers in size (PM2.5). These small particles penetrate deep into the lungs where they can accumulate, trigger inflammation and lead to decrease lung function. Once in the lungs, PM2.5 can also enter the bloodstream where it can contribute to the development of other health issues including cardiovascular disease and cognitive decline.

Although it may seem like ambient air pollution is only a problem for outside air, it impacts the quality of the air we breathe in buildings as well. Since ambient air pollutants can be introduced to indoor environments in a variety of ways including through doors, windows, HVAC systems and other aspects of the building envelope, ambient air quality can act as a predictor of indoor air quality. For instance, one estimate indicated that as much as 65% of exposures to wildfire-driven particulate matter will occur indoors.

Indoor environments can also serve as primary sources of exposure to air pollutants and recent studies estimate that levels of certain air pollutants can be two to five times higher in indoor environments than outdoors. For example, certain building materials and furnishings may off-gas volatile organic compounds (VOCs) into indoor environments while aspects of fundamental building construction may introduce airborne contaminants such as mold, which has been correlated with illnesses including asthma and bronchitis.

Figure 1: Source of indoor air pollution.

While the research is clear when it comes to the direct and isolated effects of substances such as particulate matter and mold on human health, not all exposures are straightforward. People within buildings can be exposed to a number of different hazards that can result in various non-specific symptoms collectively called sick building syndrome. Beyond the negative impact on overall health and well-being, this syndrome can also cost companies by way of sick-days and decreased employee productivity.

Air in WELL v2

The WELL Air concept aims to ensure high levels of indoor air quality across the lifecycle of a building. With the separation of topics related to Materials, Thermal Comfort into stand-alone concepts, the Air concept under WELL v2 is now centrally focused on holistic design strategies that promote clean indoor air.

The Air concept is organized around two driving principles:

1. Limit source of indoor air pollution.

2. Promote an increased supply of high-quality air.

Indoor air quality is not addressed through the Air concept alone. Features within the Materials, Thermal Comfort and Water concepts play an important role in shaping the quality of the air we breathe in buildings. Features addressing humidity (T07: Humidity Control) and moisture (W07: Moisture Management) seek to reduce mold and bacterial growth common in humid/wet environments. Proper management of bacteria and mold not only improves indoor air quality but also protects buildings from other issues such as pests and other damages. Another feature relevant to indoor air quality is feature X09: Cleaning Products and Protocol which requires projects to provide safe alternatives to conventional cleaning products to help mitigate exposure to potentially harmful chemicals and protect indoor air.

1. Limiting sources of indoor pollution

The Air concept seeks to limit sources of indoor air pollution through a variety of features. As a precondition, Feature A02: Smoke-Free Environment fulfills this goal by ensuring that occupants are able to enjoy a 100% smoke-free environment. Tobacco has played a significant role in global public health and is linked to a broad spectrum of immediate and long-term health effects for both smokers and those exposed to tobacco smoke second- and even third-hand. Therefore, smoke-free environments have been established as a fundamental pillar of all WELL Certified buildings. Feature A10: Combustion Minimization also establishes requirements aimed at limiting combustion sources (e.g. cooking and heating) that can produce toxic pollutants such as carbon monoxide.

Construction activity can also act as a major source of indoor pollution by producing both fine and coarse particles along with various other pollutants. Both fine and coarse particles are associated with various respiratory diseases including acute respiratory infection and chronic obstructive pulmonary disease (COPD). Feature A04: Construction Pollution Management is designated as a precondition to improve the quality of air during and immediately after construction.

Finally, the products in the building itself can degrade the air quality. Many types of paints, adhesives and furniture can off-gas volatile organic compounds (VOCs). To address this issue the new Materials concept contains several requirements regarding both the content and emission of VOCs from building products.

2. Increasing the supply of high-quality air

Not only does the Air concept ensure a baseline level of pollution reduction, but it also goes one step further by promoting an increased supply of high-quality air. The primary cause of sick building syndrome is underventilation which results in a buildup of CO2 and other air pollutants. Inadequate ventilation is also associated with an array of negative impacts, from physiological symptoms such as headaches and nausea to psychological effects like decreased performance at work and school. The Air concept aims to ensure that occupants are not only receiving clean air, but that clean air is delivered at optimal levels. To ensure adequate ventilation, Feature A03: Ventilation Effectiveness has been designated as a precondition, while continued efforts to enhance ventilation can be pursued as an optimization in Feature A06: Enhanced Ventilation.

The Air concept also encourages that additional steps be taken to provide high-quality air through the filtration of key pollutants. Feature A12: Air Filtration was developed with the goal of reducing indoor exposure to particulate matter, which often originates from sources outside of the building, but are brought into the building through the necessary supply of outdoor air. Particle filters are considered an effective control measure for reducing allergic respiratory disease and, when properly implemented, may reduce the risk of cardiovascular disease attributed to poor air quality.

The Air concept in WELL v2 also rewards strategies that reduce or eliminate reliance on mechanical ventilation. Although natural ventilation can pose challenges such as maintaining adequate temperature and humidity, achieving natural ventilation through operable windows can improve the human experience in a space. Studies have shown that naturally ventilated buildings have fewer people reporting symptoms associated with sick building syndrome, compared with mechanically ventilated spaces. In fact, studies have demonstrated that there is a 7.7% productivity benefit associated with naturally ventilated spaces. Therefore, when weather and local outdoor parameters indicate high-quality outdoor air, projects are encouraged to make use of natural ventilation strategies. Feature A07: Operable Windows supports this effort by promoting holistic design strategies that utilize natural systems to support occupant health and well-being.

Performance Verification

A key differentiator of the WELL Building Standard™ (WELL™) is verified performance. Our ability to monitor and verify indoor environmental performance is an important factor in our goal to deliver high-performing indoor environments for all. Under WELL v2, we’ve introduced new processes for performance verification whereby WELL projects may contract with a WELL Performance Testing Organization that employs trained WELL Performance Testing Agents. These agents are trained and qualified to conduct on-site testing for parameters across the Air, Water, Light, Sound and Thermal Comfort concepts.

Another enhancement to the performance aspect of WELL in v2 is more frequent testing through feature A08: Air Quality Monitoring and Awareness. This optimization is perfect for projects wishing to more rigorously track air quality throughout the day, in addition to improving occupant knowledge concerning the importance of doing so.

Impact and Evolution

Rising rates of urbanization coupled with the effects of climate change will continue to challenge our efforts to provide clean air in the buildings in which we live, learn, work and play. The Air concept aims to ensure that levels of key airborne pollutants are managed through proactive design and are assessed through rigorous performance verification standards.
Moving forward, the Air concept will continue to evolve under the guidance of the Air advisory. This extraordinary, global group of architects, engineers, designers and construction specialists will continue to provide invaluable guidance regarding the development and implementation of standards in the Air concept.