5 Signs Your Building Needs Seismic Retrofitting

If your building isn’t ready for an earthquake, you’re risking lives, property, and massive repair costs. Here are the top signs that your building might need seismic retrofitting:

1. Foundation Issues: Cracks, uneven settling, or sloping floors can weaken your building’s ability to withstand seismic forces.
2. Old Construction: Buildings made before the 1980s often lack modern seismic safety features, especially those with unreinforced masonry or non-ductile concrete.
3. Soft-Story Problems: Structures with open ground floors, like those with garages or storefronts, are prone to collapse during earthquakes.
4. Building Age Without Upgrades: Older buildings are more likely to fail if they’ve never been retrofitted or assessed for seismic safety.
5. Unpermitted Changes or Neglected Maintenance: Modifications without permits or skipped upkeep can compromise structural stability.

Why act now? Experts predict a 72% chance of a major earthquake hitting the Bay Area by 2043. Retrofitting costs far less than the potential damages from a collapse. If your building shows any of these signs, schedule a seismic assessment immediately.

How to check if your building needs retrofitting for earthquakes

1. Foundation Problems and Structural Damage

Your building's foundation is what keeps it steady during an earthquake. Even small issues can create weak points, especially in the Bay Area's seismically active environment, leaving your structure vulnerable to damage.

Cracks and Uneven Settling

One of the clearest signs your foundation may need seismic retrofitting is cracking. While not every crack is a red flag, certain types should grab your attention. For instance, horizontal cracks wider than 1/8 inch in foundation walls often indicate structural stress that could worsen during an earthquake[6]. Similarly, stair-step cracks in brick or block walls suggest uneven settling - when parts of the building sink at different rates - causing stress that increases the risk of damage during seismic events.

Diagonal cracks extending from door or window corners are another warning sign. Cracks wider than 1/4 inch in these areas often point to more serious structural problems beyond normal settling[4]. To monitor these issues, take regular measurements and photos to track any changes. Uneven settling, which often creates significant cracks, should always be assessed by a professional.

Visible Structural Shifts

Foundation problems don’t just stay hidden; they often show up in ways you can see throughout your building. Sticking doors, windows that no longer align properly, and floors that slope more than 1 inch over 15 feet are common indicators of foundation movement[4]. A simple leveling tool can help confirm uneven floors.

Other signs include gaps between floors and baseboards, cracked tiles, or walls separating from ceilings. If features like chimneys or porches start pulling away from the main structure, it’s a strong indication of underlying foundation issues.

Often, it’s the combination of several of these symptoms - not just one - that signals the need for a seismic evaluation.

The Bay Area’s unique geology adds to the challenge. The region’s clay-heavy soils expand and contract with moisture changes, while steep slopes complicate drainage, making foundation problems more likely[7]. These issues can have a big financial impact, too: foundation problems can reduce home value by up to 20% and lead to repair costs ranging from $1,500–$3,000 for minor fixes to over $30,000 for major ones. Delays in addressing these problems can push costs up by as much as 35%[7][8].

With a 72% chance of a magnitude 6.7 earthquake hitting the Bay Area by 2043, foundation problems that seem minor today could become catastrophic during the next big quake[5]. Spotting these warning signs early is your first step toward ensuring seismic safety.

2. Old Construction Materials and Methods

Outdated construction materials and techniques add to the seismic risks of older buildings. Structures built before the 1980s often fail to meet today’s seismic safety standards, leaving them more vulnerable during earthquakes.

This issue is widespread. In California, buildings constructed before the 1950s, and in the central and southeastern United States, those built before the 1980s, were typically not designed to withstand earthquakes effectively[16]. Significant updates to construction standards and the Uniform Building Code in the 1990s, spurred by major earthquakes and subsequent research, introduced modern safety measures. However, many older buildings still lack these reinforcements and technologies[17][18].

Unreinforced Masonry

Unreinforced masonry (URM) buildings are among the most hazardous during earthquakes. These structures, made of brick, stone, or concrete blocks without steel reinforcement, are particularly at risk because their walls and parapets are not securely attached to roofs and floors. This makes them prone to collapsing both inward and outward during seismic activity[9][10].

URM buildings have a long history of failure in earthquakes. Past events have shown that falling parapets, chimneys, cornices, and exterior walls from these structures can cause significant damage and pose serious threats to life[11].

The weaknesses of URM structures are numerous. They are heavy, which increases the seismic forces acting on them, and the masonry itself is brittle, unable to absorb the energy from an earthquake. Shaking can cause roofs or floors to detach from walls, leading to partial or total collapse. Compounding the issue, the masonry and mortar in many URM buildings have weakened over time[11].

The scale of the problem is alarming. Cities like Portland and Seattle have thousands of URM buildings - over 1,600 in Portland and approximately 1,164 in Seattle - that remain unretrofitted[11][12]. The 2011 Christchurch earthquake in New Zealand demonstrated the devastating potential of URM failures, and the 2001 Nisqually Earthquake in Washington highlighted how close such disasters could come to major urban centers[12]. Even though these examples are geographically distant, they emphasize the urgent need for seismic evaluations in areas like the Bay Area.

Non-Ductile Concrete and Tilt-Up Construction

While URM buildings highlight risks in traditional materials, older concrete and tilt-up structures present their own seismic challenges. Non-ductile concrete buildings, which lack the flexibility needed to endure seismic forces, are particularly prone to collapse[13]. The primary issue lies in insufficient steel reinforcement in load-bearing columns, making these buildings brittle and unable to withstand the stress of an earthquake[14].

The Federal Emergency Management Agency (FEMA) has identified non-retrofitted buildings as "the single biggest contributor to seismic risk in the United States today"[14]. A U.S. Geological Survey simulation paints a grim picture: a magnitude 7.8 earthquake in Southern California could lead to the partial or full collapse of 50 non-ductile concrete buildings, endangering up to 7,500 people[13].

The numbers are staggering. The Concrete Coalition estimates that California alone is home to as many as 17,000 older concrete buildings, with over 1,000 in Los Angeles. These structures are some of the deadliest in the country due to their inability to bend under pressure[14][16].

Tilt-up buildings also pose unique risks. These structures are built by casting concrete walls on the ground and then tilting them into place, with the roof added last to tie the structure together[15]. However, tilt-up buildings constructed before stricter codes often lack adequate connections between the roof and walls, making them vulnerable to collapse during earthquakes[15]. According to magazine, tilt-up buildings built before the Northridge earthquake are particularly susceptible to partial collapses even in moderate seismic events[15].

Recognizing these dangers, some cities have implemented mandatory retrofitting programs. Los Angeles requires owners of non-ductile concrete buildings built before January 13, 1977, to evaluate and strengthen their structures under Ordinance 183893[13]. Similarly, Santa Monica adopted a Seismic Retrofit Ordinance in 2017, mandating retrofits for non-ductile concrete buildings within a set timeline[13].

Fortunately, solutions are available. Retrofitting tilt-up buildings often involves reinforcing wall supports and securing roof-to-wall connections to prevent collapses[15]. Experts agree that retrofitting can significantly improve a building’s earthquake performance, reducing the likelihood of collapse and even allowing it to remain operational after a quake[14].

If your building was constructed before the 1980s using any of these materials or methods, scheduling a seismic assessment is a crucial first step to identify vulnerabilities and plan for retrofitting[13].

3. Soft-Story and Open Ground Floor Problems

In addition to challenges like aging foundations and outdated materials, soft-story conditions significantly jeopardize building safety. These structures are particularly vulnerable to earthquakes in the Bay Area due to their weak ground floors, which often feature large openings and minimal partitions, making them unable to adequately support the weight of the upper stories. For instance, many apartment buildings have ground floors dominated by garage doors, while mixed-use buildings often include large storefront windows or open retail spaces below residential units.

SFGOV outlines the danger:

During seismic activity, the upper floors act as a heavy mass, while the weak ground floor struggles to withstand the forces, often leading to a "pancake" collapse. A stark example of this vulnerability was seen during the 1994 Northridge earthquake, where the Northridge Meadows apartment complex collapsed, claiming 16 lives[2].

A CAPSS study estimates that San Francisco has between 2,800 and 2,900 buildings with soft-story conditions. Without retrofitting, 43% to 85% of these structures could be deemed unsafe after a major earthquake, with 300 to 850 of them potentially collapsing entirely[19]. Most of these buildings are wood-frame structures with at least five residential units, two or more stories, and construction permits issued before January 1, 1978[19]. This has prompted San Francisco to enforce mandatory retrofitting measures to address these risks.

Bay Area Rules for Soft-Story Retrofits

To mitigate these dangers, San Francisco introduced a mandatory retrofit program. Starting in September 2013, owners of qualifying wood-frame buildings were notified and required to submit screening forms to determine if their properties fell under the program's requirements[19]. Of the buildings screened, over 5,000 - approximately 75% - were identified as needing retrofitting.

Property owners can check their building’s status using the Department of Building Inspection (DBI) Soft Story Mandatory Retrofit Program Database. Buildings that received notices in 2013 had to complete screening forms by September 15, 2014, with the help of licensed design professionals[19]. The program categorizes buildings into tiers, with Tier IV including structures that have ground-floor commercial spaces or are in liquefaction-prone areas.

The cost of retrofitting all soft-story buildings in San Francisco is estimated at $260 million[19]. Research from Caltech highlights the financial advantages of retrofitting, showing a 7:1 benefit-to-cost ratio for shear wall retrofits and a 4:1 ratio for steel frame retrofits. This means property owners could save up to $7 for every dollar spent on retrofitting - making it a prudent investment for safety and compliance[2][21].

Seismologists estimate a 63% chance of a magnitude 6.7 earthquake hitting the Bay Area within the next 30 years, and California faces a near certainty of experiencing such an event during the same period[19][20]. With these projections, taking immediate action is not just about meeting regulatory requirements - it’s a vital step toward safeguarding lives and property.

Owners of multi-story buildings with large open ground floors should urgently verify their retrofit status. The combination of seismic risks and legal obligations makes retrofitting a necessary and life-saving measure.

4. Building Age and Missing Seismic Upgrades

Buildings constructed before the 1980s face heightened risks during earthquakes. Why? Older construction standards and materials simply weren’t designed to handle the seismic forces we now understand. This risk becomes even greater when these buildings lack documented seismic upgrades or assessments. Addressing these vulnerabilities with timely retrofits is critical.

Risks in Older Buildings

Older non-ductile concrete buildings are particularly at risk because they lack the flexibility needed to absorb seismic forces effectively [3]. These structures were built without the closely spaced steel reinforcements that modern buildings use to bend and stretch during an earthquake [3].

Here’s a staggering fact: California is home to approximately 17,000 older concrete buildings [3]. In Los Angeles alone, nearly 50 of these buildings are considered likely to collapse in a major earthquake [3]. According to FEMA, non-retrofitted buildings are "the single biggest contributor" to earthquake risk in the U.S. [3].

Reginald DesRoches, a professor at Georgia Tech, highlights the gravity of the situation:

The core issue lies in the outdated designs and aging materials of these older buildings. Unlike modern structures, which include features to absorb and dissipate earthquake energy, older buildings rely on rigid elements that are prone to failure during seismic activity [3].

Building codes have evolved significantly over time. Structures built after 1990 often include earthquake-resistant features, but pre-1980 buildings typically require retrofitting [17]. This shift in standards reflects advancements in seismic engineering and a deeper understanding of earthquake risks, emphasizing the need for thorough seismic evaluations.

Why Seismic Assessment Reports Matter

Seismic assessments are a key tool for addressing these risks. Regular evaluations ensure older buildings comply with updated seismic codes [23]. As Tsuneo Okada explains:

Building codes are updated periodically based on advancements in earthquake research, meaning that structures once deemed safe may no longer meet current standards. These evaluations help identify vulnerabilities and ensure safety before an earthquake strikes [23].

Professional evaluations are particularly valuable because trained specialists can spot weaknesses that might not be visible to the untrained eye. Industry experts note:

For property owners in Los Angeles, the Department of Building Safety (LADBS) offers an online tool to check whether a building has retrofit requirements or compliance records by simply entering the address [22]. This system has already identified more than 12,000 "soft story" buildings needing upgrades, with 95% submitting retrofit plans as of January 2024 [22].

When it comes to non-ductile concrete buildings in Los Angeles, the retrofit program has identified just under 1,200 buildings, with 61% submitting checklists for city review and 11% providing proof of retrofits or plans for retrofitting or demolition as of January 2024 [22].

Seismic assessments do more than pinpoint current issues - they also track how a building’s seismic performance changes over time [23]. This is especially important as aging materials weaken, potentially compromising a structure’s integrity.

Despite the challenges, DesRoches offers reassurance to building owners:

Proactive seismic evaluations are an important step in reducing these risks. Many cities now enforce retrofit laws for commercial and apartment buildings [22], making professional evaluations not only advisable but often legally required. By adhering to these laws, property owners can enhance safety, protect lives, and preserve property values in earthquake-prone regions like the Bay Area.

5. Unpermitted Changes or Skipped Maintenance

In addition to aging materials and outdated designs, unauthorized modifications and neglected maintenance can significantly undermine a building's ability to withstand earthquakes. Property owners who make changes without permits or fail to keep up with routine upkeep unknowingly increase seismic risks. These seemingly minor lapses can turn a structurally sound building into a hazard during an earthquake. Bay Area property owners need to recognize how these factors amplify seismic vulnerabilities.

How Unpermitted Changes Weaken Buildings

Unpermitted modifications interfere with a building's original design, often reducing its ability to handle seismic forces. Changes like removing walls or adding rooms without proper permits can disrupt load distribution and compromise structural stability.

Building codes are specifically designed to ensure buildings can resist seismic forces[24]. When property owners bypass these regulations, the building's structural integrity becomes unpredictable. Common examples of unpermitted changes that increase seismic vulnerability include:

• Removing or altering load-bearing walls.
• Adding upper floors without reinforcing the foundation.
• Installing heavy equipment without conducting a structural analysis.

These unauthorized alterations can create stress points, increasing the risk of failure during an earthquake.

Enforcing building codes is essential to protect structures from seismic hazards[24]. Without permits and inspections, property owners miss out on critical evaluations that could reveal hidden dangers.

To address unpermitted work, property owners can:

• Check local building records or use online permit portals to review the building's history[28].
• Compare the current layout with original blueprints to spot unauthorized changes[28].
• Look for signs of unpermitted work, such as new electrical panels, plumbing lines, or layout adjustments that don't match the original design[28].

If unpermitted work is identified, transparency is key. Property owners should inform potential buyers and take proactive steps to resolve the issue[28]. Hiring a licensed contractor to assess the work and bring it up to code is a practical first step. This process often involves city inspections, which may require exposing parts of the existing work for evaluation[28].

The Long-Term Risks of Skipped Maintenance

Neglecting routine maintenance can also compromise a building's structural integrity, leaving it vulnerable to earthquakes. Deferred maintenance often leads to problems like water damage, wood rot, and deteriorating materials, all of which reduce a building's ability to absorb seismic forces. Even minor earthquakes can become catastrophic for poorly maintained structures.

For example, timber buildings that lack regular upkeep can become dangerously weak, with even small seismic events posing a collapse risk[25]. The danger is compounded by the fact that deterioration often occurs in hidden areas, such as crawl spaces, basements, or inside walls.

Given the frequent seismic activity in the region - over 1,500 earthquakes with a magnitude of 5.0 or higher were recorded in 2024 alone[27] - cumulative stress from these events can accelerate the degradation of poorly maintained buildings. Routine inspections and timely repairs are critical steps in reducing seismic risks[26]. Property owners should regularly check for issues such as:

• Loose or missing bracing in crawl spaces.
• Water damage or wood rot.
• Cracks in load-bearing walls.
• Sagging floors or musty odors, which may indicate long-term moisture problems[25].

In California, landlords have a legal obligation to maintain their properties to reduce the risk of structural failure[26]. Facilities teams should review seismic evaluation reports, address any deficiencies, and implement recommended mitigation measures to improve safety[29]. Promptly addressing these issues through professional assessments can also pave the way for effective seismic retrofitting.

When to Get Professional Assessment

If your building shows any of the warning signs mentioned earlier, it’s time to consider a professional seismic assessment. Licensed structural or civil engineers with expertise in seismic design and evaluation can provide the detailed insight needed to uncover both visible and hidden vulnerabilities [30]. This step is essential for ensuring your building’s safety and compliance with local regulations.

In areas like the Bay Area, where seismic activity is a constant concern, professional evaluations are even more critical. Local amendments to the California Building Code require seismic assessments for remodeling projects involving buildings over 50 years old. Skipping this step not only increases the risk of structural failure but can also lead to non-compliance and potential legal liability.

Benefits of Professional Evaluation

A professional seismic assessment offers accurate and standardized evaluations [30]. Engineers use established guidelines, such as ASTM E-2026, to assess seismic risks for various needs [30]. These evaluations go beyond surface-level inspections, addressing site-specific hazards like soil conditions, proximity to faults, and the risk of liquefaction. The process results in a Seismic Performance Grade, which provides a clear picture of your building’s resilience [33][34].

In addition to grading the structure’s performance, the assessment estimates potential damage and evaluates how well the building might handle aftershocks [33]. This detailed analysis leads to a tailored action plan for retrofits, eliminating guesswork and outlining specific steps to improve safety. For property owners planning renovations or additions, the assessment also identifies the necessary permits and documentation required by local authorities.

Professional evaluations are particularly valuable for older buildings or those undergoing modifications. If your property was built before the 1980s or you’re planning a remodel, a seismic safety inspection ensures compliance with modern building codes. The engineer’s report serves as official documentation, often required by regulatory agencies.

Expected Costs and Timelines

The cost and duration of a seismic assessment depend on the complexity of the building and the level of analysis needed. Professionals customize their evaluations based on the building’s specific risks, ensuring a thorough and relevant assessment [32].

For example, HUD seismic assessments involve three tiers: initial screening, evaluation, and detailed evaluation [32]. The process typically starts with a site visit by a seismic expert, especially if your building falls into a high-risk category or hasn’t been retrofitted yet [33]. During this visit, the engineer evaluates the structure and determines the appropriate level of analysis.

For residential properties, assessments often follow FEMA P-50 guidelines, which focus on earthquake preparedness for homes [34]. Additionally, structural engineers are frequently required for projects involving CORPS RFPs, emphasizing that professional evaluations are a standard industry practice, not an optional step [31].

While the upfront cost of a professional assessment may seem significant, it often pays for itself by identifying cost-effective retrofitting solutions. These proactive measures can prevent more expensive repairs or structural failures in the future.

Conclusion: Protecting Your Building and Occupants

Seismic retrofitting isn't just about ticking off building code requirements - it’s about safeguarding lives and protecting your property. With nearly 75% of the U.S. at risk for damaging earthquakes, it’s not a matter of but [36]. Addressing structural vulnerabilities now can mean the difference between manageable repairs and catastrophic losses.

The financial risks are just as pressing. In 2003, legal consequences following a fatal incident highlighted that failing to retrofit isn’t just costly in terms of repairs - it can lead to severe legal and moral consequences [1]. These realities make timely retrofitting an urgent priority.

There’s also a clear financial upside to early action. Retrofitted homes can save their owners between $75,000 and $150,000 in potential repair costs. Considering that retrofitting typically costs $3,000 to $7,000, the investment more than pays for itself [38]. Beyond reducing damage, retrofitting boosts property value, lowers insurance premiums, and makes buildings more appealing to buyers and tenants.

Key Takeaways

Certain warning signs shouldn’t be ignored: foundation issues, outdated materials, soft-story vulnerabilities, unpermitted modifications, and buildings without seismic upgrades. Structures made of unreinforced masonry or non-ductile concrete are particularly at risk of brittle failure during earthquakes. Soft-story buildings, with their open ground floors, are especially vulnerable, which is why Bay Area ordinances specifically target these structures.

Buildings constructed before the 1980s are at the highest risk, especially if they haven’t been retrofitted to meet modern standards. The longer retrofitting is delayed, the higher the repair costs and potential legal liabilities become, all while safety is compromised.

To take action, schedule an inspection with a licensed structural engineer, get familiar with local regulations, and collaborate with experienced contractors to implement the right retrofitting solutions [35]. This proactive approach ensures compliance, protects lives, and secures your property value - all while keeping costs under control.

Golden State Shoring's Expertise

Golden State Shoring stands out as a trusted partner for addressing seismic challenges in the Bay Area. With 175 years of combined expertise in structural engineering and shoring solutions, they’ve successfully reinforced hundreds of properties to withstand earthquakes [37]. Their deep understanding of local building vulnerabilities allows them to deliver tailored solutions that go beyond basic code compliance.

Their work doesn’t just focus on structural safety - it also preserves the aesthetic integrity of buildings and minimizes disruptions during construction [37]. As early adopters of shotcrete technology in the Bay Area, Golden State Shoring offers advanced reinforcement techniques that enhance both residential and commercial properties [37].

Whether your building shows clear signs of seismic vulnerability or you’re planning renovations that require structural assessments, Golden State Shoring provides comprehensive engineering and construction services. Their expertise ensures your property meets the highest safety standards while protecting your long-term investment.

FAQs

What could happen if seismic vulnerabilities in older buildings are ignored?

Ignoring the seismic weaknesses of older buildings can have serious consequences when an earthquake strikes. These buildings face a higher risk of structural damage or collapse, leading to injuries, loss of life, and extensive property destruction. The increased vulnerability often stems from outdated construction techniques or materials that fail to meet modern safety standards.

Beyond the immediate risks to life and property, unchecked vulnerabilities can trigger major disruptions. Issues like gas leaks, power outages, and obstructed evacuation routes can make emergency responses far more challenging. Retrofitting these buildings not only improves safety but also ensures they meet current seismic regulations, offering better protection for both people and property in earthquake-prone areas.

How can I tell if unpermitted changes or poor maintenance have made my building more vulnerable to earthquakes?

Unapproved alterations and skipping routine upkeep can significantly weaken a building's ability to handle earthquakes. Changes that fail to meet modern seismic standards - like removing or modifying structural elements - can put the building's stability at risk. Additionally, older features such as soft-story designs or non-ductile concrete are particularly vulnerable if they haven't been cared for properly.

To minimize earthquake-related risks, consider the following:

• Ensure that any modifications are approved and comply with current seismic regulations.
• Conduct regular inspections to spot and fix issues like foundation cracks or weakened support structures.

By addressing these concerns, you can help make your building safer and more resilient during seismic events.

How can I make sure my building meets current seismic safety standards?

To make sure your building is prepared to handle seismic activity, the first step is to schedule a professional seismic assessment. This evaluation will pinpoint any structural weaknesses and help determine whether retrofitting is needed to meet safety standards.

Verify that your building aligns with the latest International Building Code (IBC) and ASCE 7 guidelines, which set the bar for seismic safety. If the assessment reveals issues, collaborate with a licensed structural engineer to create and execute a retrofit plan that fits your building's unique requirements.

Don’t overlook nonstructural components like HVAC systems, light fixtures, and other equipment. Securing these elements can significantly reduce hazards during an earthquake. Regular inspections and updates will not only keep your building compliant with changing regulations but also help protect everyone inside.

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