With natural disasters becoming more prevalent, buildings are increasingly taking a hit. Construction companies are now frequently choosing to opt for resilient design methods to build structures that can withstand high winds, hurricanes, tornados, drought, and other natural disasters.
Hurricane Sandy brought the need for resilient design to wider attention. The storm caused nearly $70 billion in damage within the United States and left thousands homeless after their residences had been rendered uninhabitable. Close to 9,000 rental units on Long Island were also damaged, according to Newsday.
In November, scientists from 13 federal agencies found in their National Climate Assessment Report that climate change will cause more devastating, costly and deadly fires and that communities still haven’t done enough to prepare.
The need for structures that can stand up in the face of events like that storm brought calls for greater use of resilient design methods.
Resilient design can ensure structures are built to withstand more intense storms, greater precipitation, flooding, drought, wildfire, warmer temperatures, and power outages, according to the Resilient Design Institute. This nonprofit has a mission to “enable buildings and communities to survive and thrive in the face of climate change, natural disasters, and other disruptions.”
Resilient Design Certification
The Insurance Institute for Business & Home Safety, a nonprofit research organization supported by property insurers and reinsurers, also calls for resilient design and has established a certification process—Fortified. There is a set of standards for resilient construction that must be met for builders to earn a Fortified certificate for their structure. The goal is to ensure buildings and residents can quickly recover in case of a disaster.
Different types of natural events happen in different places. Hence, resilient design is specific to the location of the building to be sited. The same is true for a Fortified certified building—the standards are tailored to the risks most likely to impact the area.
Some of today’s design professionals are looking to ultra-secure buildings like data centers for ways to improve the core and shell of their own buildings. Since a data center is basically a concrete box, it has more inherent protection than other structures, says Eve Hinman, president and founder of Hinman Consulting Engineers, which offers protective design services.
Of course, most businesses and residencies can’t be comprised of a simple concrete box, though some resilient designs take a page from ultra-secure buildings by beginning the design process in the same way. They consider typical use scenarios of the building, the most likely types of disaster to hit the structure, and how a local disaster could impact the building’s integrity.
Resilient structures might include features like rain screens, an air barrier between the internal wall and external cladding to allow drainage and evaporation. In areas prone to flooding, structures need to be tightly sealed and include drainage systems for roofs, terraces, basements, and any other areas where water would collect.
Construction might also include windows and walls that can withstand hurricane winds. A building’s interior could be finished with materials that dry quickly and don’t mold so that occupants can live in the structure shortly after the flooding.
Staying in Place
Resilient design goes beyond designing buildings to withstand natural disasters. It includes planning for survivability. The residents need to be able to stay in their flooded or damaged homes; they may have nowhere else to go or their entire community might have been devastated. In situations like that, disaster victims can struggle to access basic necessities, such as drinking water, power or communication systems.
For this reason, the Resilient Design Institute asks architects and builders to consider residents’ needs for what it calls passive survivability—the need for people to shelter in place for a period of time without power and things like access to running water.
That type of sheltering in place is also becoming more common in a warming climate. In March, for instance, 2.8 million people in the Northeast and mid-Atlantic remained without power after a snowstorm blew across the region. In September 2017, hurricane Irma wiped out power to 6.7 million Florida residents. Some of them were left without electricity for a week.
Design for passive survivability calls for siting electrical and cooling systems to withstand flooding and extreme weather—usually above ground and sometimes closer to the top of a building. It also calls for using materials that don’t off-gas or leach hazardous materials in the event of flooding and fire damage. Moreover, architects should consider placing composting toilets or waterless urinals within buildings or in nearby locations. Thus, they’ll guard against the event municipal wastewater facilities quit operating in the face of a natural disaster.
Policy makers are also talking about resilient design. In response to the destruction Hurricane Sandy caused to the state’s communication and transportation systems, New York Governor Andrew Cuomo established the Governor's Office of Storm Recovery (GOSR) to find ways to improve the state’s infrastructure and systems against hurricanes and flooding.
After hurricanes Harvey, Irma, and Maria, The U.S. Department of Housing and Urban Development (HUD) set stricter elevation requirements for the construction of new or substantially renovated buildings in flood-prone areas. Under the new rules, the bottom floor of these structures has to be at least two feet above the base flood elevation.
For “critical facilities,” such as hospitals, nursing homes, as well as police and fire stations, HUD’s rules require buildings to be elevated at least three feet.
A How-To Guide
IBHS and the Resilient Design Institute offer several tips architects and builders can use to ensure their structures stand up in the face of natural disasters, and long after.
Install package terminal air conditioner units at a slight angle, thus allowing water to drain in the event of flooding or heavy rainfall. For mechanical rooms, use storm-resistant louvers to maximize air intake while blocking wind and rain.
Don’t install emergency backup generators or other important mechanical systems in the basement or—depending on the location—the first floor.
Secure rooftop equipment to structural mounting curbs that directly attach to the open-web bar joists supporting the structural steel frame of the roof deck. Build masonry walls with steel reinforcement to create a continuous load path from the roof to the foundation.
Provide redundant water supplies or water storage for use during emergencies. For deep-well pumps, fit either stand-alone solar electricity or hand pumping options where possible. Where there is no option for on-site water, consider water storage that can gravity-feed to the building.
Reduce dependence on complex building controls and systems. Always provide manual overrides in case of malfunction or temporary power outages.
Use fiber-cement siding. It is fire resistant and half the price of more commonly used cedar-plank siding. Moreover, add fire-resistant roof, vents, gutters, doors, and windows to homes in fire-prone areas.
Rely on the vernacular design practices common before the advent of air conditioning and central heating. Combine these design strategies with modern materials to optimize resilient design.
Provide redundant electric systems with at least minimal backup power capacity, such as a fuel-fired electric generator or a solar-electric system with islanding capability.