These structures were under construction when the magnitude 7.8 earthquake hit Turkey. The signs out front advertise them as being “earthquake resistant.” The building in the foreground has completely collapsed, while the one still standing is experiencing 6% lateral drift. Photo by Matthew Speicher, NIST
On June 1 I received an email from my banking and insurance company, letting me know that hurricane season was beginning and I needed to be prepared. The email linked to a webpage with the headline, “We can help you prepare for all kinds of natural disasters, year-round.” This was followed by a brief video, “You never know when a natural disaster might strike,” along with instructions on how to create a disaster plan and tips and links for different types of hazards, ranging from hurricanes to winter storms to floods, hail, tornadoes, wildfires and earthquakes. Many of these links were to government sites, including www.ready.gov, funded by the Department of Homeland Security.
Why is it important to my insurance company and the federal government that I am prepared for a disaster? Aside from the fact that these two entities care deeply for my personal health and well-being, it boils down to cost: Natural and man-made disasters cost private companies and the federal government billions every year, and these costs continue to rise.
One of the ways governments around the world provide life safety (and, in turn, cost reduction) to their citizens and businesses is through building codes that help to ensure that structures are safer and less likely to cause illness or injury. This is injury prevention 24-7-365 for the life of the building, but especially during a disaster where an entire community or region is affected at the same time. And now, governments and code development organizations are working to extend codes beyond life safety, including provisions that lead to cost reduction as well. But there has been some pushback since more stringent codes come with a higher price to builders, developers and building owners.
According to Matthew Speicher, research structural engineer with the National Institute of Standards and Technology, “There are alternative approaches in the code to allow for innovations. However, the cost of taking these approaches may not be justified from a business perspective.”
Earlier this year, Speicher was part of a team of scientists and engineers who visited areas of Turkey devastated by the Feb. 6 magnitude 7.8 and 7.5 earthquakes. Those quakes and aftershocks claimed over 50,000 lives and destroyed or damaged more than 4 million buildings. After viewing the damage, Speicher agreed that if more buildings had been built to code and if fewer builders were allowed to purchase “code amnesty,” there would have been many fewer casualties and it would be less costly to restore communities and have a quicker recovery.
Functional Recovery
“Resilience” and “sustainability” are two terms that have been getting lots of press lately. Many feel that building codes should be written in a way that promotes both. Gary Ehrlich, director of construction codes and standards for the National Association of Homebuilders, says, “I’ll let you in on a little secret: If you talk to people who have been involved with the code development process, they will tell you that resilience is already built into the codes.”
He has a good point and cited examples where events such as the Loma Prieta and Northridge earthquakes and Hurricanes Andrew and Katrina had huge impacts on wind and seismic requirements in building codes. And while codes focus primarily on life safety, Ehrlich notes that the code philosophy is turning more to cost reduction after disasters. This, in turn, can shorten the time it takes for a community to reach “functional recovery,” a phrase that refers to a community’s ability to return to a high degree of functionality.
Functional recovery has many aspects beyond buildings. Infrastructure such as sewer, water, electrical power, roads, bridges and other community support systems all need to have some built-in resilience if rapid functional recovery is a community goal. And as we learned during COVID-19, some small businesses cannot survive being closed for more than a few weeks. If those businesses do not have power or water or a stable roof, it becomes very difficult to stay open.
Michael Schmeida of the Gypsum Association served as the technical contact for the development of ASTM E3341, Standard Guide for General Principles of Resilience. Schmeida says, “Both codes and code enforcement are important to resilience, but it’s up to communities to adopt and enforce the codes. Although the federal government is mandating more stringent codes, including energy conservation requirements, for their own buildings, they cannot impose these principles everywhere. And not all communities will be willing to pay for more resilient buildings.”
In the ASTM document, four interdependent principles of resilience are discussed: planning and preparation, withstanding and limiting impacts, recovery and adaptation. Building codes have a role in all of these areas but are vital to withstanding and limiting impacts.
“Some jurisdictions are going so far as saying you must be functional within 24 to 48 hours of an event,” says Jonathan Humble of the American Iron and Steel Institute. “In New York City, they were ready for Hurricane Sandy except for one problem. The floodline … was 2 feet higher than what had been predicted by the FEMA regulations and maps. … Those buildings that did upgrade had all their equipment above the proverbial floodline; however, because the water was 2 feet higher [than expected] the buildings had to shut down.”
This was unfortunate because the city’s plan for a low-level hurricane or tropical storm was not to evacuate but to shelter in place. The preparations for shelter in place ensured that residents had plenty of food, but other essentials that relied on electrical power were not available: refrigeration, air conditioning, cooking and, in some places, running water. Then Humble aptly noted, “That’s not a building code issue, that is an ordinance or local law issue.”
Should Codes Be More Proactive?
Stories like this beg the question: If natural disasters are getting worse, then should the codes be proactive in having buildings built for these more severe effects? The answer: not necessarily. At the American Society of Civil Engineers Structures Conference in New Orleans this year, several panels and speakers discussed this very issue. Terri McAllister, the community resilience group leader and program manager for NIST, stated that “lots of communities will take the last worst event they had and use that to plan the resilience of their communities, and that is nowhere near the design event they should be considering.”
According to Ehrlich, “The data we have is incomplete. We may have more data and better models than we had 10 years ago, but we still do not know with certainty how severe, when and where the next storm/wildfire/earthquake will hit.”
What we do have is probabilistic models that tell us what areas have the highest risk, and these models produce a range of data that is built into the codes. So, if you want to build a barn that would have a low impact on life safety or replacement cost if it collapsed, and it is not essential for functional recovery of the community, the codes permit it to be built to a lower standard, which is represented by a lower probability (higher mean recurrence interval) for catastrophic events.
But if you want to build a fire station or a hospital, something that will retain full functionality both during and after the event, then the design is for a much higher mean recurrence interval—say 500 years rather than 50 years. For design loads, the document most referenced by the International Building Code is ASCE 7, Minimum Design Loads and Associated Criteria for Buildings and Other Structures. ASCE 7 provides design charts and tables for various recurrence intervals of multiple hazards, allowing designers to choose what level of loading is most appropriate for their type of structure. There are certain minimums, but the existence of these tables allows owners and designers to choose higher levels of protection for their buildings if they are willing to pay the cost.
According to Matthew Speicher, at a design team meeting structural engineer David Mar, after presenting his design for an innovative earthquake-resistant foundation system that increased design costs by only one-quarter of 1%, wryly noted that “everyone will take resilience if it is free.” Although this is true, some communities are willing to pay more for resilience because they see the benefits of mitigation, or have been devastated by a recent catastrophe. A recent study from the National Institute of Building Sciences showed that on average, adopting and building to the model codes saves $11 in recovery and reconstruction costs for every $1 spent implementing code requirements. This is according to the 2019 NIBS report, “Natural Hazard Mitigation Saves,” which goes on to state, “Given the rising frequency of disaster events and the increasing cost of disaster recovery across the nation, mitigation actions are crucial for saving money, property and, most importantly, lives.”
Contractors Can Make a Difference
So, with all this data, why do our costs continue to increase? There are two primary reasons. First, we are building more densely in at-risk areas. Just look at the development in areas most prone to hurricanes (the Atlantic and Gulf Coasts) and you can see that there are many more people and structures in harm’s way. Second, we have lots of old building stock that needs to be retrofitted to come up to a level of resilience that matches what communities and governments desire. This second reason is being addressed by many communities, and it goes hand in hand with their carbon reduction efforts in the face of climate change. It takes vastly more energy and embodied carbon to demolish and rebuild a structure than to renovate an existing one and bring it up to or beyond current codes. And sophisticated owners and concerned communities are doing just that.
This is where wall and ceiling contractors have the opportunity to make a difference. Many construction contractors do a fair amount of renovation work, but with the new codes and design methodologies focused on resilience and carbon reduction, this work should steadily increase. Property owners will think twice about demolishing old buildings and instead opt for upgrades in building envelopes and insulation. Unfortunately, some jurisdictions have developed conflicting code provisions that make it hard to meet these requirements.
“An unfortunate example is New York City,” says Schmeida, “which has virtually eliminated exceptions for firestopping in exterior walls with combustible materials. This, coupled with their mandate for building energy efficiency, has severely restricted the options that designers would normally have for exterior continuous insulation systems such as exterior insulation and finish systems.”
So, as we prepare for the next big event, and as our insurance companies and government agencies remind us how to prepare our homes, businesses and communities for natural and manmade disasters, designers and planners will hopefully remember these facts:
Although building codes play a role in all of this, the code is merely a minimum requirement, and it is useless if it is not adopted by states and local jurisdictions. As citizens, we should all engage with our elected officials and let them know that current building codes are a simple, cost-effective way to build resilience in our communities.
Don Allen, PE, SE, LEED AP, is AWCI’s director of technical services. He can be reached at [email protected].
