Across the United States, new construction is meeting higher resilience standards than in the past, thanks to the adoption of updated codes and public–private initiatives. However, at least one significant pain point remains: our existing building stock.
Fifty million houses—or 40 percent of all residences in the U.S.—are located in wind zones 3 or 4, classified by the Federal Emergency Management Agency (FEMA) as having gusts of up to 200 mph to 250 mph. According to a December 2016 White House report, a majority do not meet the 2015 International Residential Code (IRC). Single-family homes lag behind commercial buildings in the race to resilience because they are more likely to be built independently, with little oversight, which is particularly true with older houses. As a result, they are less likely to have licensed professionals behind their design, construction, and renovation.
When it comes to resilience, a unified effort at the local level is key. Think of a city as a network in which all building types must interact in the wake of disaster. If an earthquake or a flood destroys a critical mass of buildings, the resulting displacement could have crippling effects on both families and the economy. Thus, many communities are exploring ways to redesign the existing building stock to a standard that keeps them usable and protects quality of life throughout an ordeal like a natural disaster.
In an era of dwindling governmental resources, the task can be daunting: It requires a consensus on benchmark goals that is then coupled with targeted investment. But there is no shortage of approaches that are being explored nationwide. We take a look at a few here.
In 2011, the deadliest tornado in U.S. recent history hit Joplin, Mo. The EF-5 twister (with sustained winds in excess of 200 mph) killed 161 people, injured more than 1,000, and caused nearly $3 billion in damage. Pragmatically speaking, you can’t design for an event as rare as this—fewer than one in a thousand tornadoes are classified as an EF-5. However, meeting the 2015 IRC guidelines, which require designing residences to resist 115-mph bursts in wind hazard areas—which translates to roughly an EF-2 force—can go a long way. Ninety percent of tornadoes never exceed EF-2, and those events account for the majority of property damage from twisters.
Joplin overhauled its building code and completely rebuilt its infrastructure, which included a new hospital and immense storm shelters built into schools that can accommodate the entire student and faculty population plus all residents within a quarter- to half-mile of each school.
Similarly, Moore, Okla., resolved to rebuild after the worst in a series of tornadoes killed 24 people and destroyed more than 1,000 homes in 2013. Many residents opted to build safe rooms in their yards with the help of FEMA rebates for up to 75 percent of the cost, administered through block grants to the state. But Moore is only one city. Across Oklahoma, in-school safe rooms and shelters are hard to come by, with fewer than half of the state’s 1,773 schools reporting a safe shelter in 2015, a casualty of lackluster funding and political dysfunction.
In Arkansas, the University of Arkansas Community Design Center (UACDC) is redesigning tornado shelter prototypes to be more accessible and safer, with measures such as strengthening foundation anchoring. (And yes, before you ask, tornadoes have literally sucked shelters from the ground.) FEMA has shown interest in collaborating with UACDC and potentially replicating its designs.
A Wake-Up Call in the Pacific Northwest
Oregon is taking a pre-emptive approach to practicing resilient design. The Cascadia Subduction Zone, one of North America’s most active seismic areas, is a source of growing concern. Following scientific estimates of a 40 percent chance of a magnitude 8 or 9 earthquake hitting the state in the next 50 years, and in light of the devastation caused by Japan’s 2011 Tohoku earthquake and tsunami, the state legislature decided to get serious about creating a resilience policy. Of particular concern are coastal communities and unreinforced masonry buildings (UMBs), many of which are multifamily apartment buildings.
The legislature requested the state seismic committee produce a plan that emphasizes accelerating retrofits to UMBs and strengthening schools and civic buildings that offer livable shelter. It subsequently created a task force to prioritize the passing of legislation to implement the recommendations made in the resulting Oregon Resilience Plan (ORP), says Jay Raskin, FAIA, chair of the National Institute of Standards and Technology Community Resilience Panel and a Portland, Ore.–based architect involved in developing the ORP.
The ORP recommended that the state government adopt existing voluntary, performance-based rating systems—ASCE 41: Seismic Evaluation and Retrofit of Existing Buildings and FEMA P-55: Coastal Construction Manual—and to advance these standards through education and incentives. “Time will tell whether this will be effective and/or whether public sentiment will support its adoption at the code level,” Raskin says. “We mainly worked outside the codes, outlining goals and producing guidelines. A lot of attention has been given [in the ORP] to upgrading existing buildings and infrastructure to current codes, along with efforts for voluntary upgrades to above-code standards.”
Initiatives in the Eastern Metropolises
Older coastal cities in the East are staring down the increasing risk of storm surge flooding, and many of them have sprung into action. Boston has made resilience a major focal point, which includes efforts to ensure it can bounce back from a “shock” event, such a terrorist attack or natural disaster. The city is keenly aware of the age of its buildings—more than half of its residential stock predates World War II—and of the critical shipping and transportation infrastructure that hugs its shoreline. Mayor Martin Walsh set the strategy in motion in late 2015 when he enlisted the Transatlantic Policy Lab to study and develop social equity policy recommendations.
According to a study by the Boston Harbor Association, had 2012 Hurricane Sandy’s landfall corresponded with high tide, 6 percent of the city would have been underwater. At the former Charlestown Navy Yard, which would have been submerged, one project has been designed to withstand disaster: Perkins+Will’s Spaulding Rehabilitation Hospital. Opened in 2013, days after the Boston Marathon bombing, the center was thrust into the spotlight for its role in treating dozens of those severely injured.
In the process, Spaulding’s defenses against rising seawater gained notice as well. The building is sited 2.5 feet above the site’s 500-year flood plain. An artificial reef of excavated rock offers a buffer to the building while its underground parking garage has an entry ramp engineered to wall off floodwaters. Essential functions are located on higher floors, and the HVAC system is tucked into a two-story penthouse.
Meanwhile, Hurricane Sandy was a big wake-up call in New York City, where 68,000 buildings were inundated in the storm. Almost half of them were uninsured and outside of a designated flood zone. “Flooding doesn’t exactly match the maps,” says Illya Azaroff, AIA, director of design at +Lab Architects.
Mayor Mike Bloomberg’s office convened a Building Resiliency Task Force that drew on the expertise of more than 200 architecture, engineering, real estate, and code professionals to study the city’s built environment. In 2013, the task force issued 33 recommendations for new and existing structures, which have been steadily moving through zoning amendments and local building code changes.
“The NYC code is already so much more robust than ICC codes,” says Azaroff, who also co-chairs AIA New York’s Design for Risk and Reconstruction committee. The city has made playbooks to help people living and working in areas at flood risk embark on a retrofit.
Azaroff does bemoan the lack of public funding and oversight for resilience capacity across the region and country. “Our funding model in the U.S. relies on private investment for resilience work,” he says. “We need to establish a feedback loop to learn how to better measure and define [resiliency]. I don’t think there’s a real understanding of what it looks like.”
Enacting all of New York City’s proposals, from code changes to dune systems, floodwalls, and levees, will cost $19.5 billion. That figure may sound high but for context, Hurricane Sandy caused the city $19 billion in damages and economic loss alone.
Staying Proactive is Tough
Financial incentives are key to achieving whole-community resilient design, particularly when it comes to existing housing stock. Numerous state-sponsored and not-for-profit programs are encouraging responsible residential rebuilds in hazard areas across the country.
Notable examples include Shore Up Connecticut, a state-funded, low-interest loan program that provides financing or refinancing to homeowners and small businesses for property elevations and retrofits in select coastal flood zones; and Rebuild Northwest Florida, a not-for-profit that helps homeowners procure FEMA grants to repair and strengthen homes against major wind events.
Despite the alarming history of storm damage, “we’re seeing a lot more waterfront investment and development,” says Rachel Minnery, FAIA, the senior director of sustainable development policy at the AIA. “A home builder only needs their product to last the life of a loan.”
Some 260 condominium buildings are now under construction on the South Florida coast, Minnery says. While climate change is an increasing concern among real estate professionals, a recent Miami Herald report found that buyer groups are far less aware.
Higher risk areas, of course, place more demands on public services. Some cities have addressed this with a resilience tax. San Francisco imposes a nominal flat tax on all parcels that is directed to redeveloping wetlands. However, Minnery believes the private insurance sector must account for the true costs of climate change before any meaningful shift away from flood-zone development occurs. “When flood insurance is unaffordable,” she says, “then people will retreat.”
Read more about the role of building codes on advancing resilient design in the built environment in ARCHITECT's February story "Driving Resilient Design, One Edition at a Time."