The scale of earthquake risk often feels abstract until the numbers come into focus.
Researchers estimate that earthquakes cause roughly $14.7 billion in building losses each year in the United States. That figure alone hints at why seismic retrofits now sit at the center of so many resilience conversations. Most of the country’s vulnerable buildings were constructed long before modern codes existed, which means resilience depends heavily on what can be done with what is already standing.
Rami Tawasha, a structural resilience advisor, put it simply during a recent discussion: “Retrofitting is where communities gain ground. New buildings help, but the big risks live in the old stock.”
His point captures the practical side of the issue. Managing retrofits is often the most direct path to reducing casualties, lowering repair costs, and keeping essential operations running after a major event.
The Framework Behind Retrofit Decisions
Every retrofit project leans on a mix of national standards and local expectations. FEMA, USGS, and the NEHRP framework provide the backbone for hazard data and engineering methods.
From there, ASCE/SEI 41 guides how existing buildings are evaluated and updated. It defines performance targets, including life safety, immediate occupancy, or something in between, and that choice becomes the anchor for design.
Owners often expect retrofits to make their buildings earthquake-proof. FEMA is clear that this isn’t the goal. Retrofits reduce risk and damage; they don’t eliminate either. That small clarification often resets expectations early in planning, which prevents surprises later when budgets and timelines tighten.
Local ordinances add another layer. Cities with high seismic risk, especially along the West Coast, have pushed mandatory retrofits for soft-story multifamily buildings, unreinforced masonry, and older concrete structures.
The Technical Realities That Complicate Retrofits
Retrofitting an existing structure rarely follows a straight line. Hidden conditions, undocumented modifications, and material deterioration often complicate the initial assessment. Engineers rely on selective demolition, testing, and old drawings when available. This might seem basic, but information gaps can change both cost and design direction midway through a project.
Different building types carry their own challenges:
- Soft-story wood-frame buildings often need strengthened lateral systems because the open first level cannot resist shaking.
- Unreinforced masonry tends to fail at wall-diaphragm connections, which means anchoring and strengthening them is essential.
- Non-ductile concrete can suffer brittle failures, so columns, collectors, and joints usually require focused reinforcement.
Nonstructural components also matter more than many owners expect. Damage to ceilings, mechanical equipment, and façade elements can sideline a building even when the structural frame performs well. Nonstructural failures contribute heavily to downtime and economic loss, especially in hospitals and large commercial spaces.
Managing the Project: Where Engineering Meets Real-World Constraints
Seismic retrofits succeed or fail based on how well managers handle disruptions to daily operations. Many buildings, particularly apartments and offices, cannot simply shut down for months. That forces teams to phase work, schedule around occupancy patterns, or target exterior interventions first. It becomes a logistical puzzle as much as an engineering exercise.
Permitting can also add friction. Agencies may require triggered code upgrades, like fire protection, energy updates, and accessibility improvements, once major structural work begins. Small decisions early in design can ripple into significant changes later if project teams do not plan the sequence carefully.
Market conditions create another challenge. Skilled labor shortages, especially for specialty contractors, are common in high-seismic regions. When multiple owners face the same local mandates, demand spikes.
Rami Tawasha noted this dynamic as well: “The engineering might be straightforward, but the capacity to build is the real bottleneck in some cities.” It is a quiet constraint, yet one that shapes project timelines across entire regions.
The Economics: Making the Case with Hard Numbers
Owners often need a clear economic reason to proceed, particularly when retrofits are not legally required. The National Institute of Building Sciences (NIBS) offers one of the clearest data points: resilience investments can return up to $13 for every $1 spent. That ratio reflects avoided repair costs, reduced downtime, and fewer emergency needs after a disaster.
Some national analyses go even further. When looking specifically at seismic retrofits for high-risk housing types, NIBS estimates that roughly $25 billion in retrofitting could prevent around $330 billion in future losses. This is not a theoretical model; it’s grounded in community-scale analysis backed by FEMA and USGS inputs.
The financial case strengthens when considering the indirect effects. Facilities that remain functional after an earthquake shorten community recovery times. Businesses reopen faster. Residents stay housed. These outcomes explain why so many state and city programs now tie funding eligibility to performance targets, not just bare-minimum repairs.
Solutions That Project Teams Rely On
Retrofit strategies tend to follow common patterns, though each building requires its own combination.
- Strengthening lateral systems with shear walls, braced frames, or moment frames.
- Improving diaphragm performance so seismic forces redistribute correctly.
- Upgrading vertical elements such as columns or collectors in older concrete structures.
- Using isolation or damping systems in critical facilities where downtime carries heavy consequences.
- Securing nonstructural components to reduce operational disruptions.
Performance-based approaches continue gaining momentum. Teams identify the recovery state a building should achieve after an earthquake and design backward from that target. This method helps owners budget with more clarity because it aligns dollars with functional outcomes rather than minimum thresholds.
Planning Across a Portfolio Instead of One Building at a Time
Large owners, such as universities, healthcare systems, and corporate campuses, rarely retrofit buildings one by one. Instead, they screen their portfolios to identify the highest risks, then move into detailed ASCE-41 evaluations only where needed. This sequence prevents spending large sums on buildings that pose relatively low hazard exposure.
Phasing strategies vary:
- Rolling upgrades floor-by-floor in towers
- Night or weekend work in commercial settings
- Exterior-only reinforcement when tenants cannot relocate
Prioritizing by risk, rather than by age or size, delivers the largest resilience gains per dollar spent. It is a simple idea, though often overlooked when retrofit programs begin under tight time pressure.
Final Thoughts
Seismic retrofits can look technical from the outside, yet the real story is far more human. Communities depend on buildings that stay safe and usable during difficult moments. Retrofits remain one of the strongest tools for reducing long-term losses, supporting recovery, and preserving essential services. And as the field continues to evolve, the work becomes not just about strengthening structures but helping entire regions stand on firmer ground.
