- Putting it Together: Seeking Examples of Resilient Design
Resilient Design-Smarter Building for a Turbulent Future
By Alex Wilson
I began an eight-month sabbatical in 2011 with a bicycle trip through the Southwest. I chose the Southwest in part because I wanted to have time to think about some of the vulnerabilities we face—particularly with climate change—and what we should do about it. From what climate scientists are telling us, we don’t have the luxury of continuing the modest pace of green building adoption; we need to achieve greater change, and we need to do it faster. What better way to wrap my mind around global warming and such vulnerabilities as drought and wildfire than a six-week bike trip through the parched Southwest?
Much of the route I traveled had seen barely a drop of rain since the previous fall.
Spring wildflowers were absent. The statuesque saguaro cacti were shriveled from lack of water. Ponds were dried up, and rivers were barren gravel beds. In West Texas, I went through places like Fort Davis amid record wildfires that eventually burned more than 3.7 million acres in the state.
Getting home was harder than planned for a very different reason. Even as Texas was enduring the worst drought in the state’s history, record flooding was occurring in the Mississippi River basin in May, and my train from Houston was cancelled due to flooded tracks.
Back home in Vermont, we experienced record flooding from Tropical Storm Irene at the end of August. Hundreds of miles of highway and dozens of major bridges were destroyed, and some communities were cut off for a week or more. By August, according to the U.S. Department of Homeland Security (DHS), 2011 had already broken a record for the largest number of billion-dollar weather-related disasters in a calendar year.
Then, two months later, an early snowstorm blanketed the Northeast, toppling millions of trees and causing power outages that lasted up to two weeks in places. As we go to press, record cold and snow is killing hundreds in central Europe, while much of the U.S. is hardly experiencing any winter at all.
Below, I describe five insights that became clear to me during my bicycle trip and the research and writing upon my return home. Some of these insights may be unpleasant to consider, but it’s imperative that we think strategically about our vulnerabilities and begin addressing them immediately. Fortunately, there is reason for optimism. With two decades of green building experience to guide us, we have the tools we need to prepare: with a few changes—the most important being a change of mindset—sustainable design can readily become resilient design.
1. Resilience Is About Common Sense (and Dollars)
While there has always been a “business case” for sustainability, that’s no longer an afterthought. DHS andare embracing resilient design and net-zero goals because they must: it’s a matter of saving lives—not to mention billions of dollars. According to DHS, the ten major weather-related disasters of 2011 caused $50 billion in economic losses.
According to a recent report from the Natural Resources Defense Council, in addition to temperature changes, climate scientists predict wildly varying localized water-related vulnerabilities that will threaten the very basics of life, affecting infrastructure on every level: water delivery, power production, agriculture, communication networks, and transportation (seeEBN Sept. 2011). Adapting to climate change will necessitate achieving resilience in our buildings and communities. In fact, I believe that key aspects of resilient design can be incorporated into building codes and mandated. Some of these measures could be a very deep shade of green—close to Passive House or Living Building Challenge standards, even—but the motivation would be life safety rather than environmentalism.
“Resilience is another way of thinking about the design of buildings and communities,” says Chris Pyke, vice president for research at the U.S. Green Building Council, who has led the organization’s focus on adaptation to climate change. He says that resilience is changing our time horizon and adding a new expectation for buildings—that they should perform for decades into the future across a wide range of conditions. “It’s on a par with the sort of ‘integrated design’ we’ve applied to energy and water,” he told EBN.
2. Climate Change Is Not Our Only Vulnerability
Adaptation to the effects of climate change will be the primary motivator for resilient design—but not the only one.
The U.S. has more than 3,400 power plants, 160,000 miles of high-voltage power distribution lines, 150 oil refineries (nearly half along the Gulf Coast), and 2.5 million miles of oil and natural gas pipelines. These are vulnerable not only to floods and droughts but also to terrorist attacks. DHS is concerned that cyberterrorism (in which controls of power plants and energy distribution systems are hacked into and interrupted) may be an even greater threat in the future, as control of this infrastructure becomes more consolidated.
We are also vulnerable to political turmoil that extends well beyond our control. Should Iran stop the passage of oil tankers through the Strait of Hormuz, some experts say that crude oil prices could double; despite increasing domestic production, the U.S. still depends on foregin sources for half our oil. Extended power outages, interruptions in petroleum supply, or significant price increases in heating oil, gasoline, and natural gas would change our way of life very quickly. While such events might not cause shortages outright, they could put the price of gasoline, heating oil, and potentially other fuels out of reach for many lower-income Americans.
3. The Aftermath Is Also an Emergency
There is a lot of focus on creating disaster-resistant buildings (designing to stringent hurricane codes, raising buildings above flood elevations, achieving fire-safe construction) but much less on how buildings will make out with power outages, potential interruptions in heating fuel, and water shortages.
For most Americans, about the only strategy employed for dealing with the aftermath of a storm is buying a generator—but we learned with Hurricane Katrina that when fuel can’t be delivered, many generators will stop working after as short a time as 24 hours. Few were still working after a week. That power outage lasted more than two months in some places.
During severe droughts, too, the risk of power outages grows. Roughly 89% of U.S. electricity is produced in thermal-electric power plants that require huge amounts of water for cooling. With severe drought, power plants sometimes have to be turned off for want of cooling water—as happened in the fall of 2007 in the Southeast and during a severe drought and heat wave in Europe in 2003. Experts are already warning about that possibility in Texas should the drought persist this year.
While it’s easy to focus on—and fear—winds, floods, and wildfires, true resilience means being prepared for the much longer-term disruptions these disasters leave behind.
Keeping people safe in their homes during an extended power outage is a top priority in any climate. Space conditioning can be essential to survival during extreme weather, but the vast majority of heating systems require electricity to operate, so if we lose electricity we lose heat. Similarly, many newer homes are designed to rely on air conditioning rather than natural cooling. The good news is that we already know how to design buildings that will maintain safe, livable conditions if the heating and air conditioning systems don’t work.
Here in Vermont, with more than 7,000 heating degree days (most years), we can create homes that will never drop below about 50°F in the middle of winter. With an exceptionally energy-efficient building envelope and passive solar gain, there should never be a risk of frozen water pipes, let alone people suffering from hypothermia. In colder climates, we should be looking at superinsulation levels that are not too far from Passive House standards.
In hot, humid places like New Orleans, we know how to design homes that will maintain reasonably comfortable temperatures on even the hottest summer days: we can do this, in part, by looking at how past generations built homes prior to the widespread availability of air conditioning. In the early 1900s, homes there relied on vernacular (regionally adapted) architecture, with such features as wraparound porches to shade windows from direct sunlight, tall ceilings with operable windows to allow warm air to rise and escape, and open breezeways to channel cooling breezes through the home. The importance of cooling will increase with global warming, even in northern areas such as Chicago. Cooling degree days there are expected to increase 30%–60% by 2070, according to a new report by the U.S. Green Building Council and the University of Michigan.
If these resilient design features look an awful lot like green building features, that’s not a coincidence. Resilient design strategies are largely the same as sustainable design strategies, but the motivation in this case is one of life safety—the same sorts of motivations that led to the creation of fire, structural, and seismic building codes.
Daniel Williams, FAIA, suggests that we should design (or redesign) buildings and communities to take advantage of natural systems. “You find out what’s there and you design for it,” he said, using the example of his own home in Seattle. He found that the ground stays 68°F year-round, so he ground-coupled his new house so that it could benefit from the thermal mass of the earth. During a cold spell and power outage a few years ago, his house stayed at 58°F with no added heat, while his neighbor’s dropped to 28°F.
5. Resilience Is About Communities, Not Bunkers
Even if we create a wonderful, superinsulated, green, single-family home that can be heated with a golden retriever and air-conditioned with a glass of iced tea, there will remain significant vulnerability if the homeowners remain 100% dependent on cars. Other aspects of sustainable building that we’ve been pushing for years—like density and walkability—are also crucial to resilience. Multifamily housing has an inherent advantage when it comes to community resilience because of the density and lower energy loads.
Brad Liljequist, project manager at the net-zero-energy zHomes project in the Seattle area, is highly supportive of passive, low-input buildings, but expresses what may be common concerns about certain aspects of the concept of resilience. He is afraid that too much focus on resilient self-sufficiency will shift us away from community reliance to a sort of bunker mentality where people stockpile MREs (meals ready to eat—military rations) and guns to fortify themselves. “That is not the sort of resiliency we need, and I fear that’s where we’re headed,” he told EBN.
While resilience does deal with disasters (and we even recommend safe rooms in our checklist of actions), community is absolutely crucial to preparation, recovery, and long-term sustainability. Local food production, local businesses, and local planning are all critical. By paying attention to resilience now with a focus on sustainable towns, cities, and regions, we can work toward community-based solutions before extreme disruptions occur.
"Resilient Design: A Checklist of Actions" provides a quick overview of strategies that can help us achieve resilience in homes, other buildings, and communities. Just the barest introduction to each of these strategies is provided; look to other EBN articles (from our archives and forthcoming) for further detail.
Putting it Together: Seeking Examples of Resilient Design
Some of the individual ideas discussed in this article are pretty far out-there—so the number of individuals or communities putting a lot them together at once is small. However, I expect more examples to appear, particularly as groups like the Transition Movement grow, with a push for community-based local resilience. Here are a couple case studies already built.
zHome is a ten-unit townhome development just east of Seattle. Completed in 2011, the all-electric, highly insulated, PV-powered homes are designed for net-zero energy and to use 70% less water than conventional townhomes. Key services are within walking distance, and there is easy access to public transit into Seattle.
A sampling of key features:
• R-38 walls and R-60 ceilings
• Ground-source heat pumps
• Annual per-unit modeled heating load of 970 kWh and total energy consumption of 5,300 kWh (compared with an energy code baseline of 14,000 kWh)
• Rooftop photovoltaic modules designed to enable net-zero-energy performance
• Rainwater harvesting with 1,700 gallons of storage per building; filtered water used for toilet flushing, clothes washing, and landscape irrigation
• Dual-flush toilets, 1.4 gallon-per-minute showerheads, and other water-efficient plumbing fixtures and appliances
• Porous pavement and rainwater gardens to capture most stormwater onsite
• No lawns
Despite some reservations about the concept of resilience, project manager Brad Liljequist notes, “If you want to think in post-apocalyptic terms, I do think zHome can evolve much more easily into a comfortable, livable, off-the-grid neighborhood than typical. There’s even enough heat energy generated by several people living in a zHome to keep it at a reasonable baseline temperature. The average person puts out about 100 watts of heat energy at rest, and that can go as high as 500 watts with a lot of activity.”
Morse home – Guilford, Vermont
Eric and Dale Morse live in rural Vermont. While they are dependent on a car to get into town for shopping, their 2,000 ft2 home embodies many elements of resilience and performs remarkably well during the frequent power outages experienced in the area. “The house is really comfortable,” says Eric. “We have a back-up propane furnace, but never use it,” he told EBN. With a few provisions for power outages, they do just fine. “We keep some batteries for a radio, and candles, and we have ice in the freezer. I like keeping it really simple.”
A sampling of key features:
• Well-insulated building envelope with significant passive solar gain
• A floor plan that allows a wood stove on the lower floor to heat the entire house; during power outages they can cook on the wood stove or propane cooktop
• Solar water heating with back-up provided by a heat exchanger in the wood stove that thermosiphons up to the same storage tank
• A spring that gravity-feeds water to the house, where a pump and pressure tank are used to achieve standard water pressure—but an ability during power outages to turn some valves and deliver water using just gravity (at about 24 psi of water pressure)
• A large garden that provides a significant fraction of their fresh produce
In an industry that already has many labels and certification systems, I cringe at the idea of yet another. But there is something intriguing about the idea of some sort of overlay certification that would recognize the ability of a home or building to resist storm events and maintain livable conditions should there be extended power outages, interruptions in heating fuel, or shortages of water.
While buildings certified through the Living Building Challenge (LBC) would likely meet this standard, there are many other aspects of LBC that will likely limit participation. (Note that a “net-zero-energy” building isn’t necessarily resilient if the PV system that provides its net-zero-energy performance is grid-connected and goes down when the grid goes down.) Perhaps some other certification would be useful. The Department of Homeland Security, in fact, is planning just such a certification. Called “Resilience STAR,” the program will reportedly be piloted in vulnerable communities throughout 2012.
I could foresee insurance agencies offering discounted rates for homes that would be likely to suffer less damage in a storm or whose occupants would be less likely to require temporary housing following an ice storm that knocks out power in the winter months. The Federal Emergency Management Agency (FEMA) might also find very appealing the idea of a standard that could be required when the agency pays for the relocation of houses following flooding or damage by a hurricane or tornado.
It is possible to use energy software tools, such as Energy Plus, to model drift temperatures of buildings if conventional heating and air conditioning inputs are cut off. Such modeling could be a key part of a resilience certification. If you have thoughts on this, please post them in the comments section of the online version of this article.
Adaptation + Mitigation
Focusing on resilient design does not at all mean that we shouldn’t continue focusing on mitigation of climate change. Indeed, the importance of preventing or slowing climate change is paramount. But the need for resilience recognizes that climate change is under way, and we must pursue adaptation strategies as well as mitigation.