As New Orleans and the Gulf Coast area undergo reconstruction, building codes for homes and public buildings should include "passive survivability" designs that allow them to serve as livable refuges should a Hurricane Katrina-level crisis return to the region.
And, given the increase in concerns about natural disasters, terrorism, blackouts throughout the nation, what's good for New Orleans is good for the nation as well.
Alex Wilson, Environmental Building News (EBN) executive editor and president of EBN's publisher, BuildingGreen.com, says "passive survivability" should be a no-brainer, given that building codes are designed to protect the health and safety of a building's occupants.
"I use this term to refer to the ability of a building to maintain critical life-support conditions for it's occupants if services such as power, heating fuel or water are lost for an extended period," Wilson explains.
The design technique comes with a bonus or two -- it often incorporates "green" or sustainable building features that provide energy conservation, efficiency and ease of maintenance.
"Passive survivability can be achieved by incorporating the sustainable design features that have been so actively promoted by the green building community: cooling-load avoidance strategies, capabilities for natural ventilation, a highly efficient thermal envelope, passive solar gain, and natural day lighting," says Wilson.
"Buildings can go even further with features such as generating and storing photovoltaic electricity and collecting and storing rainwater, but the aforementioned passive survivability measures are most important," he added.
Building "passive survivability" into structures is an outgrowth of a three-day charrette on Gulf Coast reconstruction last November at the U.S. Green Building Council's Greenbuild Conference in Atlanta. Passive survivability design features are included in the recently published "New Orleans Principles," a report generated by the charrette.
"Most of us in the green building community don't need another motivation to design buildings that are energy-efficient, bio-climatically appropriate, and environmentally responsible. We do it because we believe it's the right thing to do. But for that segment of the public that doesn't believe in global warming or doesn't believe that pollution from energy consumption is a real concern, the notion of passive survivability just might provide such motivation‹because it is a way to directly protect the public in the event of a natural disaster, terrorist action, or other event that causes an interruption in our access to critical resources," Wilson explained.
Wilson says, the conventional solution to long term power loss is back-up generators and a fuel supply for a building's short-term critical functions.
Passive solutions, however, can overcome some of the cost and operational shortcomings of generators which often don't provide air conditioning, general or task lighting, or even heating and ventilation except where there are very large generators say for hospitals and other emergency operations.
Houses, apartment buildings, and public buildings, especially schools and civic buildings that could be used as emergency shelters, should incorporate design features that will maintain livable conditions in the event of extended loss of power, heat, or water.
After Hurricane Katrina, temperatures in the New Orleans Superdome rose as high as 105 degrees Fahrenheit
"Relative to building performance, the idea is not to maintain temperatures within the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) defined comfort zone of 68 to 81 degrees Fahrenheit, depending on the season and humidity, but to create buildings that will not threaten the lives of their occupants if power is lost," Wilson said.
Wilson says passive survivability-equipped structures, while helping to keep their occupants safe, are also inherently less energy dependent and that can reduce operating costs.
And who knows, building with survival in mind could transform cookie-cutter architecture into a more vernacular architecture based on the demands of a given region.
"There was a reason why homes in the Southeast had wide porches and large roof overhangs 200 years ago, why the New England saltbox had most of its windows on the south, and why homes in the Midwest's tornado belt were so often bermed into the ground. A design criteria of passive survivability would bring back these vernacular styles," Wilson insists.
