Defining Resilience

The concept of building for resilience has been increasingly adopted by different organizations over the past five years. The definitions and phrases used to define resilience from six sources are compared and a single definition incorporating these is developed.

Organizations use different definitions of resilience or different phrases to describe resilience:

• The Industry Statement by 21 organizations defines resilience as “the ability to prepare and plan for, absorb, recover from, and more successfully adapt to adverse events.”

• The National Institute of Standards and Technology defines community resilience as “the ability of a community to prepare for anticipated hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions.”

• The Department of Homeland Security defines resilience as “the ability to prepare for and adapt to changing conditions and withstand and recover rapidly from disruptions. Resilience includes the ability to withstand and recover from deliberate attacks, accidents, or naturally occurring threats or incidents.”

Different definitions of resilience and what adverse events are included in resilient design vary across organizations and are compared. The events, disruptions, or hazards are often described in general terms, such as “natural,” “technological,” “adverse,” and “human caused.” These can include designing for climate change, floods, wind (tornado and hurricanes), earthquakes, tsunami, drought, landslides and unstable soils, fire including wildfire, terrorism, and other events.

The phases to be included before, during, or after the adverse event also vary.

In summary, resilience is to:

• Plan or prepare for the natural or human-caused hazard or event by anticipating the risk, which can include addressing risk and mitigating risk

• Adapt to changing conditions

• Withstand, absorb, or limit impact while preferably maintaining functionality during the event

• Recover (preferably rapidly) and regain functionality after the event

Resiliency can be accomplished through risk assessment, design, construction, and preparation.