This study confirms the detrimental affects of an environment with poor indoor air quality and poor ventilation. While not aimed at the Passive House, the writer assumes that the Passive House practitioners realize that along with the energy saving benefits of low rate of air infiltration should come an indoor environment that is itself not harmful to the health and well being of the occupants. Otherwise it's like building an air tight bubble with a skunk trapped inside: not a very pleasant, or healthy outcome.
I love the energy efficiency results the Passive House Standard brings. Hopefully it will evolve to include more elements of a Sustainable built environment and will grow into a standard that considers all the other elements of a high performance building and takes a holistic and healthy approach to building ecologically sensitive buildings.
In early June, the Institute of Medicine of the National Academies issued a report entitled “Climate Change, the Indoor Environment, and Health” which found that climate change could affect indoor environments as buildings seek to become more energy efficient. The report was commissioned by the EPA to summarize the effects of climate change on indoor air quality and health.
In particular, the report found that measures to reduce energy use in buildings, such as lowering ventilation rates, may cause higher exposures to pollutants emitted from indoor sources. In addition, extreme weather conditions associated with climate change may lead to more frequent breakdowns in building envelopes, which could lead to water infiltration into indoor spaces.
Elderly and Poor Could Be at Risk
The report found that elderly, low-income, and people in poor health are particularly vulnerable given that at many of these individuals are housebound and are thus vulnerable to poor indoor air quality and extremes of heat and cold. In addition, an increase in extreme weather events (a likely effect of climate change) could lead to more frequent power outages that could expose people to extreme heat or cold and/or to harmful emissions such as carbon monoxide from portable back-up generators.
Many Materials New and Untested
The report also found that efforts to make buildings more energy-efficient may restrict ventilation, stating that the push to improve building energy efficiency has spurred more rapid introduction of untested new materials and building retrofits that limit and alter air flow. This could have the effect of concentrating indoor pollutants such as chemical emissions and environmental tobacco smoke. Other risks include chemical emissions as old building materials get damp and corrode either from increased dampness outside or from poorly designed HVAC systems.
Recommendations Include Implementing Ventilation Standards
The report makes a number of recommendations to EPA, including expanding or developing programs that identify at-risk populations, implementing ventilation standards for public buildings, conducting research about the potential adverse health effects of climate change mitigation and adaptation efforts, revising building codes to reflect expected climate change effects, and educating the public about these effects.
Green Buildings are Not Health Hazards
Several articles discussing the report have somewhat misleadingly suggested that green buildings are hazardous to your health (such as the one published on The Hill). First, as far as I can tell, the report does not limit itself to looking at “green” buildings, or even buildings that have achieved some level of LEED certification. It simply states, among other things, that buildings that attempt to achieve greater energy efficiency could expose their occupants to indoor air pollutants without a corresponding improvement in building ventilation, whether the buildings are “green” or not.
Second, many buildings that have achieved some level of LEED certification or another green building rating (such as the Passive House standard) will likely have met enhanced building ventilation requirements and are also more likely to have used materials that are non-toxic and do not offgas air toxins. Third, these buildings are also likely to be better insulated, thus reducing their occupants to extreme heat and cold as well as moisture from the outside.
Credit: Tyrone Turner, pictured on IOM’s report.
