Indoor Air Quality Update 2012-2019: Beyond the Energy Efficient Home

Since the Stone Age, the evolution of our dwellings has taken us from caves then huts, cabins and houses. By the early 20th century, the changes of indoor plumbing and electricity revolutionize the way we live. By the 1950s, home heating moved from coal, to oil, to gas.The children of this era, growing  up in a post-World War II America, and their children in turn, see a 30-year fast-forward in the set-up of the home environment.

Following closely on the heels of the 1962 publication of Rachel Carson’s “Silent Spring,” the energy concerns of the early 1970s give way to an “Environmental Age.” An emphasis on energy conservation in the home brings an increase of insulation levels in floors, walls, and ceilings.By the 1980s, the demand for cooling makes air conditioning a standard house feature. Ongoing efforts to reduce energy consumption, the addition of renewable energy measures, and the 1990s mindset of environmental friendliness, let to the Green Building age of the 2000s.

By 2012, energy matters remained at the forefront, often with a goal of building a “Net Zero” energy consumption home with the directive of “built it (air) tight.”

Building a better home is sometimes easier said than done, as there are always external conditions to consider. Warmer, wetter, and more humid weather dampens building materials and the completion schedule. The builder constantly searches for new, qualified workers who can achieve acceptable results on energy efficiency, sustainable development, meeting or exceeding building code, environmental friendliness, and other market pressures. However, in the drive to build a better, tighter house, indoor air quality has taken a back seat. The result? Over the past 40 years, indoor air quality conditions have declined. Today, we have regrettably entered the age of Sick House Syndrome.

Without doubt, in the southern Appalachians, local environmental conditions must be taken into account when considering what constitutes “good” building technology and practices. As climate change continues, those of us living and working in western North Carolina need to become aware of what our home environment means to our health, individually and collectively.

According to a 2012 article in the Journal of Allergy Clinical Immunology: In Practice,  “Climate Change and Our Environment: the Effect on Respiratory and Allergic Disease,” the human response to climate change will produce specific types of innovations. In 2019, let’s take a look at three topics from this study and see where our region is on the status of indoor air quality.

1. …“The response to climate change is expected to produce efforts for better energy efficiency and tighter housing.”The short answer is yes, we are seeing increasing levels of green and sustainable development as newer homes are being built. Bear in mind that older, existing homes will also be occupied for many decades into the future. That means that we also need to decrease the amount of greenhouse gas production coming from the average, older mountain home.  Today, studies show that existing occupied homes contribute about 25% of total greenhouse gas production. Over the course of the next century, this number will need to be cut by 80%. Think about that: your family’s future consumption will need to be 20% of current levels.This fact deserves our consideration, and can be restated in more critical terms. What can we do now and in our lifetimes to maintain optimum wellness, energy efficiency, and comfort in our living and work spaces?
2. …”Housing is expected to undergo energy reduction retrofits that involve superinsulation strategies and reduced exchange of indoor-outdoor air.”Super-insulation strategies are being seen in today’s super energy efficient, net zero energy, green homes. Outfitting older existing homes with these same energy-efficient and air tightness solutions seems like a no-brainer.However, the reduced exchange of indoor-outdoor air could be problematic. If the house isn’t “breathing,” it means that the trapped impurities in the air of the home could become increasingly concentrated. The 2012 study says this will likely result in decreased healthiness in the home in the form of increased illness. We agree. Sick house syndrome will be on the rise in the future, yielding serious illnesses with environmental triggers or risk factors.The apparent answer to creating tighter homes is to “ventilate.” If we see the practice of “fresh air” ventilation, it’s primarily the practice of exhausting stale indoor air and introducing “fresh” outdoor air.A “dark side” lurks behind this air exchange strategy. Increased exchange of indoor-outdoor air means that increased humidity will be pumped into the air inside the home. This humidity raises the dampness level indoors. Unhealthy volatile organic chemicals then release from materials inside our house. The indoor populations of molds, bacteria, mites, and insects increase, along with the adverse toxins, allergens, and irritants they create.Simply, when indoor air pollution goes up, indoor air quality goes down.
3. …”The Environmental Protection Agency (EPA) has ranked indoor air pollution among the top five environmental risks to public health.”Indoor air pollution is a problem in need of solutions for western North Carolina homeowners concerned about healthiness. In many cases, attention will need to be placed on indoor humidity, overall air quality, and the way the air moves into and out of a structure.Damp, moldy buildings inevitably lead to respiratory illnesses, such as asthma. According to the  2012 study, …“everything from asthma to chronic obstructive pulmonary disease is believed to be affected in a negative way by increased air pollution.” Increases in population density also suggest an increase in communicable respiratory disease is possible.

Meeting the challenges of air quality, population growth, housing development, and Sick House Syndrome in WNC requires that we summon our cooperative, creative abilities. We must re-direct our focus to indoor air quality and take the long overdue, inevitable, next step beyond the Age of the Energy Efficient Home into the Age of the Healthy Home.

In the Age of the Healthy Home, outdoor climatic conditions in our region, such as wetness and humidity, definitely influence indoor air quality. Indoor air quality is critical to human health, but discussions about its effects will need to gain traction in the public arena. Healthy home professionals will be asked to understand the indoor air quality needs of individuals and families and consider where those areas of concern intersect with the ecosystem of the house and regional climatic conditions.

Continued climate change, the mutable nature of work, and smart home technology will likely cause dramatic shifts in the way people dwell within their mountain homes. In much the way that respiratory disease is an anticipated increased risk for humans in the decades ahead, houses without healthiness strategies may also result in indoor air quality “sicknesses” that increase occupant illness symptoms, challenge immune systems, or even trigger the onset of disease.

Now upon us is the challenge to adapt the present course of our green building practices to these ends.

The next evolutionary step in the endeavor to build a better dwelling requires that we prevent Sick Building Syndrome in new and existing housing stock. The next generation of green and sustainable builders will want to produce resilient, energy efficient homes specifically designed maintain the healthiness of indoor environmental conditions.