This article was written by our Engineering Director, Codes and Compliance, Jeff Ellis.
There’s been a lot of discussion recently about resilient buildings and resilient communities, including what it means to be resilient, why it’s important, whether it’s possible within budget constraints, and how it can be achieved. The 100 Resilient Cities Rockefeller Foundation initiative defines “urban resilience” as “the capacity of individuals, communities, institutions, businesses, and systems within a city to survive, adapt, and grow no matter what kinds of chronic stresses and acute shocks they experience.”
The discussions have noted that communities are made up of several components that are necessary to consider when developing a plan for resilience — such as buildings, infrastructure, water, power and communication. Even though community resilience is multi-faceted, the resiliency of buildings is a crucial component because research shows that Americans spend 90% of their day inside buildings.
Why are resilient buildings and communities important? In developed countries, we see minimal loss of life in events like earthquakes, as compared to what we see in developing countries. To give some perspective, a recent USGS analysis found that, if 10,000 people were subjected to violent shaking comparable to that of the 2016 6.2 magnitude Italian quake, 3,000, 150, and 3 of those people could be expected to die in Iran, Italy and California, respectively.
Is life safety all that we need for community resilience, though? Even with the best safety outcomes, earthquakes can still bring communities to their knees by the closure and required demolition of huge numbers of buildings. In Christchurch, New Zealand, a city of 370,000 in 2011, at least 627 commercial buildings required demolition, in addition to the partial demolition of many others. It is taking years to recover, leaving many people without homes or businesses.
Thankfully, there’s been a lot of technological development recently to support the design of resilient buildings and resilient communities — moving beyond safety alone and toward designing buildings and communities that can be functional following disasters.
There are several new resources, tools and mandates to increase community resilience. From the community-level perspective, the National Institute of Standards and Technology (NIST) recently developed a community resilience planning guide to help communities understand the various aspects of resilience and guide them in the development of a strategy to achieve it. For treating existing buildings, some cities, such as San Francisco, Los Angeles and Santa Monica, have mandated retrofit ordinances for buildings vulnerable to collapse in an earthquake. For new buildings, there have been recent deliberations either requiring resilience in the building code or stimulating market demand for resilience through a building rating system, such as that provided by the U.S. Resiliency Council. A building rating system would inform consumers (owners, tenants, community leaders) of their building’s performance so they can make informed decisions, not unlike car-crash test ratings.
In support of resilient design of new buildings, there are new analysis methods, such as FEMA P-58, and supporting software such as the SP3 software. In addition, some communities have implemented a back-to-business program where building owners engage engineers before a natural disaster strikes, so that they’re familiar with the building and are deputized after the event to red-, yellow- or green-tag a building, thus reducing the time for that building to become operational once again and decreasing community recovery time. The question remains – is safety enough? Many argue that safety is not enough, and that we should not be okay with our communities being non-functional for months or even years after a natural disaster. The good news is that we now have the ability to better pursue building and community resilience, thus allowing communities to recover more quickly.