Environmental Building News Calls for Incorporating “Passive Survivability” into Building Codes

Thursday, April 3, 2008
CONTACT:
Jerelyn Wilson
802-257-7300 ext. 102

Brattleboro, VT, April 3, 2008—In an age of heightened risk of natural disasters, terrorism, and future energy shortages, we are more likely to experience heat waves, blackouts, and fuel supply interruptions. Our houses and apartment buildings should be designed to maintain livable conditions in the face of these events. Environmental Building News (EBN) unveiled this design strategy, called “passive survivability,” in 2005, and the idea has generated growing interest throughout the country since. Now, in the most recent issue of EBN, Executive Editor Alex Wilson proposes that passive survivability is more than just a good idea; it should be incorporated into building codes like other life-safety issues (see www.BuildingGreen.com/go/survivability).

“We require that houses resist collapse and the spread of fire,” says Wilson. “Why not also require houses that protect us from the elements when power or heating fuel is lost?” The same argument applies to schools, and other municipal buildings or government buildings that could serve as emergency shelters.

Passive survivability can be achieved with such features as a highly insulated building envelope, passive-solar design, cooling-load avoidance, natural ventilation, and daylighting—design strategies that are key components of energy-efficient, green building design today.

Housing built to achieve passive survivability will almost never drop below 55°F, a temperature adequate for livability. Occupants may have to bundle up, but they won’t risk dying of hypothermia. And such housing equipped with a small heat source, such as a woodstove or kerosene heater, could be kept comfortable during a power outage or heating fuel interruption because of the insulation and other passive survivability features.

Similarly, in the summer months, a passively survivable house or apartment won’t get so hot that residents are at risk of heat stroke or hyperthermia—blamed for over 700 deaths in Chicago in 1995 and 35,000 deaths in Europe in the summer of 2003. Overhangs will block the hottest sunlight, and windows will provide natural ventilation—as our warm-climate vernacular designs did before the advent of air conditioning.

“We have tremendous vulnerability in our cities,” notes Wilson. “An extended summertime heat spell coupled with an accident or terrorist action that interrupts power delivery, or a drought that causes water levels to drop so low that nuclear and coal-fired power plants have to shut down due to lack of cooling water, could spell disaster for hundreds of cities around the U.S.” During the winter months, a shortage of natural gas or heating oil could prove equally tragic—especially if schools and municipal centers identified as emergency shelters were relying on the same heating fuel. “With worldwide demand for oil now exceeding available supply, these concerns are not unrealistic,” argues Wilson.

“The good news is that we know how to design and build housing that won’t get too hot during the summer or too cold in the winter,” says Wilson. Part of the answer is found by combining today’s best practices of energy-efficient, passive-solar, green building practices, and part is found by looking back at regionally appropriate, vernacular buildings that existed before air conditioning came along. “Houses on the Gulf Coast in the late 1800s,” according to Wilson, “had deep roof overhangs and wrap-around porches that kept the summer sun out, and they were designed to benefit from summertime breezes.”

An obvious side benefit of passively survivable housing is the very small ecological footprint. Under normal operating conditions, such housing would use little energy for heating and cooling, which reduces greenhouse gas emissions. “Even while passively survivable housing will shelter us in the event of power outages or loss of heat,” argues Wilson, “it can help prevent catastrophic climate change.”

Wilson is beginning to examine how passive survivability could be incorporated into building codes—and he’s reaching out to some logical partners in such an effort, such as the insurance industry. One priority is to determine what constitutes “livable conditions” and how that varies regionally. Another priority is to identify building performance metrics, such as the Home Energy Rating System (HERS) scale, to define passive survivability. Code authorities and government leaders also need to be convinced that interruptions in electricity and heating fuel supply present a significant enough life-safety risk that we should incorporate passive survivability into all new housing.

Wilson has been a strong proponent of voluntary green building programs, especially the LEED Rating System, but he is not convinced that these programs can be adopted quickly enough to protect the public. He believes that global climate change and energy shortages on the horizon are making us more vulnerable. “We have a responsibility to ensure that houses and apartments keep their occupants safe and protected from the elements—just as we have a responsibility to ensure that they won’t collapse from snow loads.” Wilson suggests that we take that responsibility seriously and mandate, through building codes, that our housing will keep us safe, even without power or supplemental heat. “Let’s not wait for the tragedy of a major summertime heat wave or wintertime cold spell that coincides with an extended power outage or fuel shortage before we act.”

BuildingGreen, LLC has been providing the building industry with quality information on sustainable design and construction since its founding in 1985. Publications include Environmental Building News, the GreenSpec Directory of green building products, and the BuildingGreen Suite of online resources. For information, visit www.BuildingGreen.com or call 802-257-7300. To contribute to an ongoing discussion about passive survivability, e-mail .

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Editors: Alex Wilson is available for interviews about passive survivability. To arrange an interview, contact Jerelyn Wilson at 802-257-7300 ext. 102 or .