Build disaster-proof homes before storms strike, not afterward
T. Reed Miller
On Breezy Point in Queens, New York, construction will start soon on Diane Hellreigel’s new house. Dubbed the #HurricaneStrong Home, it will replace a house built in 1955 by Hellriegel’s grandfather that was wrecked during Superstorm Sandy in the fall of 2012.
The demonstration home was designed by private companies working with the Federal Alliance for Safe Homes, or FLASH, a nonprofit coalition that promotes action to strengthen homes and prepare for disasters. It features a solid concrete foundation that elevates the living space above floods, and uses energy-efficient insulated concrete form (ICF) for the walls and floors designed to withstand wind and blown debris.
The roof deck of the demonstration home uses principles from the Fortified Home standards, a set of national guidelines designed to improve on minimum building codes and make structures more disaster-proof. They include taped plywood seams to prevent water entry, and reinforcing spray foam insulation underneath the roof to help keep wind from blowing it off and also improve energy efficiency.
Projects like the #HurricaneStrong Home demonstrate that there are many technologies we can use to make our buildings more hazard-resistant. But we are not using them as extensively as we should. Instead of designing a building to reduce potential damage from the hazards it may face over its lifetime, most construction projects focus on saving money up front. By choosing the lowest construction cost possible, homeowners, insurance agencies and taxpayers may end up paying for it many times over when natural disasters occur.
Forecasting storms and mitigating damage
Although we cannot always predict far in advance when a disaster will strike, we do know that climate change will result in more frequent and intense storms than in the past. Hazard modeling has progressed considerably over the past several decades, and we can make strong predictions of roughly how often to expect disasters from coast to coast.
Researchers from a variety of disciplines are developing tools that can help us make smarter decisions about mitigating storm damage by preparing the built environment in advance. FEMA has designed free software tools that embed hazard models to help evaluate the impacts of disasters on individual buildings and the larger community. The Benefit Cost Toolkit compares the effectiveness of different mitigation strategies for a particular building and location. The Hazus-MH software maps out expected damage in a community from multiple hazards and allows comparison of “what-if” scenarios, such as “what would the economic benefit be if this community reinforced or rebuilt its vulnerable building stock?”
At the MIT Concrete Sustainability Hub, we are creating life cycle cost analysis models to include the costs and benefits of mitigation efforts alongside operational costs such as utility bills and maintenance. In our case studies we have demonstrated that investing in more hazard-resistant residential construction in certain locations is very cost-effective.
We have also developed a metric called the Break Even Mitigation Percent (BEMP) to address the cost-effectiveness of mitigation features for a particular new building in a particular location. The BEMP factors in the expected damage a building designed to code would endure over its lifetime, compared to a more resilient building design.
As an example, we compared two designs for a four-story apartment building located on the Gulf or Atlantic coasts – one constructed with nonengineered wood, the other with more resilient engineered concrete – and modeled the damage that these buildings would be expected to sustain over 50 years. For a building sited in Galveston, Texas, we estimated a BEMP of 3.4 percent, meaning that if US$340,000 was invested on top of the initial $10 million costs in order to build the stronger version, that investment would mitigate enough storm damage to the building over its lifetime to pay for itself.
It is important to note that BEMP considers costs from the perspective of society at large. That’s because the original homeowners might not occupy a building 30 years later when a hurricane rolls through, so they might not directly recoup the value of investing in a resilient design – unless the mitigation features allow them to resell the house at a higher value, which can happen. But insurance agencies, taxpayers and future occupants certainly will all benefit from investing up front to make buildings more storm-resistant. Neighboring homes will also benefit from fewer building material projectiles flying off storm-resistant homes.
Injecting mitigation into building codes
More hazard-resistant buildings produce broad social benefits. If a community can recover from a disaster more quickly, the disaster’s negative impact on the economy and vital systems like health care and education can be reduced. Importantly, hazard resilience means lives can be saved.
But architects and designers often have a different incentive: keeping construction costs low. This is why most new construction projects just meet code requirements, instead of making extra investments to weather disasters well. Builders do not often consider reconstruction costs – the money that owners, insurance agencies and taxpayers will spend in the future to recover after the first structure fails in a storm.
To address this disconnect, the nonprofit International Code Council spearheads Building Safety Month each May to spotlight the need for modern building codes, more aggressive code enforcement and better training for building inspectors. However, the United States does not have a national building code with federal enforcement. Instead states, and sometimes municipalities, devise their own approaches. This patchwork system is inefficient and ineffective. A similar situation exists in cyclone-prone Australia.
This past May the White House hosted a Conference on Resilient Building Codes to highlight the importance of developing codes that incorporate resilience and future climate change impacts. One state that has embraced this approach is Florida, which adopted progressive statewide building codes after Hurricane Andrew in 1992. These requirements have substantially reduced insured losses in subsequent hurricanes.
Congress underfunds mitigation
At the federal level, though, most spending on mitigation occurs after disasters strike. Up to 15 percent of federal assistance can be allocated to long-term hazard mitigation measures after the president declares a major disaster. For instance, after a hurricane, states often use these funds to retrofit and elevate buildings, protect infrastructure and utilities, and manage stormwater.
The Federal Emergency Management Agency (FEMA) also awards pre-disaster mitigation grants (PDM), which states and communities can use to reduce risks from future events. But recent Congressional appropriations for PDM have fallen far short of what is needed. Last year FEMA requested $400 million for PDM but received only $81 million. From 2005 to 2014, appropriations averaged just $120 million each year. Compare that to the $7.2 billion spent on average on recovery assistance; PDM grants accounted for only 1.6 percent of total FEMA grants on average.
Recognizing that the current approach is not sustainable, this spring FEMA proposed a disaster deductible. The policy would require states to invest in resilience efforts before receiving public assistance funding after a disaster.
Post-Sandy rebuilding in New York
Diane Hellreigel’s home was among 100,000 damaged in New York during Superstorm Sandy. Of those, 20,000 owners applied for New York City’s Build It Back program in 2013, but construction has been completed on only 1,887 units. City leaders are working to make New York more resilient against future disasters through steps that include funding coastal protection projects and modifying local building codes pertaining to flooding.
Congress earmarked over $13 billion to fund Hurricane Sandy recovery in New York City alone. That sum includes $595 million for FEMA assistance to affected individuals and families. Overall, however, just 5.3 percent of FEMA funding for Sandy went toward hazard mitigation grants.
These efforts are encouraging, but many coastal and inland communities remain vulnerable to natural disasters. To prevent the devastation from another storm, twister or quake, we need to make deep investments nationwide in mitigation now, before the next disaster strikes.Comment on this article
T. Reed Miller works for the MIT Concrete Sustainability Hub which receives funding from the Portland Cement Association and the Ready Mixed Concrete (RMC) Research & Education Foundation.