Time to tackle sick building syndrome
Envision a phantom phenomenon that could be taking place inside the crevices of your own personal space. An uninvited and unwelcome mysterious guest that has yet to be fully uncovered, "sick building syndrome" is the diagnosis used to link building occupants who experience specific symptoms with the amount of time spent in a whole building or room.
While the exterior environment has its own problems, we need to scrutinize the interior environment as well. With all the new additions of ‘green’ products and construction techniques that are delivered or adopted by our building industries, I wonder whether energy efficiency has become a compromise over human health. With widely renowned benchmarks such as the International Energy Conservation Code shaping policy and guiding design and construction energy efficiency, it’s no wonder the hype may be overly encompassing.
Says architect and LEED AP Carol Kurth of Carol Kurth Architecture, PC + Carol Kurth Interiors, "It's admirable that codes are addressing issues with respect to air infiltration as a means to save on energy consumption. However, the IECC is solely focused on energy use - and that is NOT the whole picture for a healthy environment - indoor air quality needs to be taken into account for a healthy home."
According to the Environmental Protection Agency, Americans spend nearly 90% of their time indoors. So are there legal guidelines in the design and construction phases that oversee our indoor air quality?
Particularly with the onset of new technologies, who is governing the health of building occupants? LEED (Leadership in Energy and Environmental Design) has taken steps in this direction, by establishing a mandatory Indoor Environmental Quality category within its guidelines. Obtaining LEED certification requires a minimum indoor air quality performance which adheres to ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers). The specific rule moderates that buildings must follow ventilation rate for mechanical systems as designated by ASHRAE 62.1-2007, or follow passive ventilation (natural ventilation). Architect David Businelli of Studio 16 Architecture confirms that building codes require a certain percentage of fresh air be brought into the HVAC system, which is "probably the most important factor in occupant health and comfort."
Energy efficiency seems to be the core concept around which construction trends revolve. However, vital components of the ‘green' revolution, which include a tighter building envelope and resulting minimum infiltration, could actually be the cause of sick building syndrome! Sick building syndrome’s root causes are the off-gassing of volatile organic compounds (VOCs- toxic chemical gases) from interior products (paints, coatings, adhesives, carpets, rugs, wood products, furniture and furnishing systems), insufficient air filtration and ventilation, and poor air volume and temperature.
Moreover the lack of moisture control in buildings leads to the development of moisture and mildew. David Businelli affirms this theory. "Sick building syndrome is not a recent discovery; about 40 years ago the thinking was that sealed buildings, office towers and such, and its limited outdoor air intake were the most energy efficient. It was then discovered that the occupants of those buildings over time were getting sick. It was determined that the lack of a significant quantity of fresh air, along with the off gassing of certain materials such as carpeting, lead to what was called sick building syndrome. The root causes haven’t changed – off gassing of materials used in interiors and the lack of fresh air intake."
Widely renowned organizations have also reported incidences of sick building syndrome, citing building systems as a cause. Oxford Journals published observations on the study of 42 office buildings. The study of occupants concluded that mechanically ventilated buildings yielded more reported symptoms than with naturally ventilated buildings. In other words, "design characteristics" of the building played a role in spreading the sensation.
A study by Cornell University also produced the same results. By conducting a survey of over 1500 building occupants and studying building conditions, there were implications that physical symptoms were connected to building ventilation performance. Do we really need to allocate extra funds for a mechanically ventilated envelope at the sacrifice of indoor occupant health? David believes the trend towards increasingly tighter buildings more than likely contributes to sick building syndrome. He explains, "If the building can’t 'breathe', then mold can grow in damp areas hidden from view and some of the off-gassing can’t all be vented from the building."
There seems to be a large disconnect in the emerging technologies and the actual occupants themselves! It seems as though the phenomenon has not been brought clearly enough to light. Kurth provides an example. "The ramifications of 'foam insulation' products and 'tight' homes are yet to be studied long term, over a period 10 to 20 years. In my opinion, the Building Codes have tunnel vision and do not address issues such as off-gassing, allergens and poor indoor air quality as a result of introducing these chemically based products inside the building envelope."
The lack of transparency in interior products may also be playing a role. I decided to dive into various products that claim to contribute to indoor environmental quality. I found many manufacturers list material and safety data sheets publicly on their websites, often citing zero VOC’s. Several of these refer to Section 112 of EPA’s Clean Air Act as a guide. The act provides provisions for air pollutants.
However, further research shows that this section includes only "major" pollutants- those that create "serious health effects". Here I pose several concerns- what is defined as major? What is defined as serious? Are VOCs that emit fewer tons of pollutants each year not considered? What if we are slathering on large volumes of these products inside our home? What about the fact that off-gassing can occur months and even years after such finishes are applied? Does the accumulation over time deteriorate indoor air quality, making these ‘zero-VOC’ claims misleading? These are classic examples of green-washing: deceptive marketing that leads us to believe a company is using environmental practices when, in fact, the intents may simply be financial!
Exterior Insulated Finish-Systems are also a popular option which present their own array of dilemmas. This exterior surface application is highly susceptible to moisture penetration, essentially trapping water within its back cavity. Further evolution leads to mold and mildew formation and structural deterioration. Businelli explains, "EIFS is probably one of the worse cladding systems – because if it is not installed properly moisture can build up behind the insulation boards and cause a mold problem."
As Carol Kurth has observed, "Years ago, EIFS was touted as the best way to clad your home for a maintenance-free exterior with added benefits of having extra insulation, saving money for homeowner's on heating and AC bills. A number of years later, it was a disaster - there were cases of homes with mold growing inside, a result of poor construction and lack of understanding of vapor barriers and flashing details needed. Occupants were getting sick, and homes had to be condemned as a result. And this is when the foam (rigid) insulation was on the outside of the building!"
The driving cost to upkeep energy efficiency in buildings may also play a role in how sick building syndrome continues to thrive in buildings. "So called 'green' systems can be very high maintenance, and building management may not continue to pay the high cost of maintaining such systems over time, leading to less than optimal system performance," explains Businelli.
I believe that in order to investigate the issue of energy efficiency and human health in the interior environment, we can take several steps. Businelli believes that there is an over emphasis on energy efficiency, citing the example of overly tight buildings potentially causing "more harm than good."
First, there must be much more widespread third party verification in the industry. Various industry standards do exist. Amongst air quality standards are Green Label and Green Label Plus by the Carpet and Rug Institute, GreenGuard for product emissions, and FloorScore for floor coverings and adhesives. Additional certification parties test indoor air quality and energy efficiency amongst other traits: Green Seal, EcoLogo, SCS, Cradle to Cradle, and NSF are just a few.
As David asserts, "There are many products out there, and careful specification of interior finish materials also helps combat the syndrome, as does proper maintenance. Many interior products are very good in terms of VOC output, and should be carefully specified to maximize indoor air quality."
How many of these certification parties require products to publicly label their ingredients? LEED’s new 4.0 version incorporates an amendment that pushes product manufacturers to acquire a third party verification of its ingredients. These LEED credits emphasize disclosure of the ingredients, which I feel may not be as accurate as actually studying the impact of the ingredients.
Second, I believe we need a stronger life cycle analysis. I continue to believe that construction, architectural design, and interior design together play a role in sick building syndrome. I envision a standard which would require buildings to develop a maintenance report to verify the performance of its MEP systems, structure, interior finishes, etc.
In addition, an occupant survey, one that is conducted for a long period of times (I imagine five to ten years after initial occupancy) would allow us to see what symptoms, if any, the building occupant may be experiencing. Any changes in environmental comfort (i.e. temperature) may allow us to develop a clearer link between human health and energy efficiency!
Topics: Indoor Air Quality
Farah Naz Ahmad was born in New York City and holds a Bachelor of Architecture degree from The City College of New York. She is a LEED Accredited Professional in Building Design + Construction. Her career goal is to make an impact on the field of sustainability in design and construction. Her past roles as President of CCNY's American Institute of Architecture Students and as a team leader for the US Department of Energy Solar Decathlon have increased her passion for eco-friendly design.www