5 Building Design Features That Increase Earthquake Risk
As we move into the second half of the year, it’s a smart time for commercial and industrial property owners to take stock of their building’s health—beyond routine maintenance. One often-overlooked area? Seismic design risks—structural vulnerabilities built into a property’s layout that can increase earthquake damage, even in newer or well-maintained buildings.
Some buildings carry hidden weaknesses—not because of their age or condition, but because of how they were designed. Certain architectural features can compromise a building’s ability to withstand seismic forces, even if everything appears structurally sound.
Read Earthquake Risks of 5 Commercial Building Types
A mid-year building safety audit is the perfect time to evaluate whether your property includes any of these high-risk design elements—and to make a plan for mitigating them through targeted seismic retrofitting or structural repair.
Addressing seismic design risks early can help avoid costly damage, project delays, or disruptions down the road.
Architectural Features That Create Seismic Weakness
Here are five common architectural features that can compromise structural performance during an earthquake:
1. Re-entrant Corners
Re-entrant corners are inward (or outward) notches or sharp inside angles in a building’s shape—often seen in “L,” “T,” or “U”-shaped layouts. During seismic shaking, these corners may move differently than adjacent sections of the building, causing stress concentrations and potential cracking at the joints.
A re-entrant corner irregularity is typically defined when the notch extends more than 15% of the building’s total length in two perpendicular directions. Without reinforcement, these areas can become points of weakness.
Common examples: Office buildings with courtyards, shopping centers with inset storefronts, or apartment complexes with winged floor plans.
2. Soft-Story Conditions
A soft-story condition occurs when the first floor of a multi-story building is significantly weaker than the floors above—typically due to large openings and fewer supporting walls. This is common in structures with ground-level parking or retail space.
Soft-story collapse is one of the most well-documented types of earthquake failure, as the bottom level may buckle or pancake under the weight of the upper stories during shaking.
Common examples: Apartment buildings with tuck-under parking, retail buildings with glass storefronts, or mixed-use spaces with open lobbies.
3. Cantilevered Overhangs
Cantilevered sections are areas where part of a floor or roof extends beyond its supports—like balconies, second-floor pop-outs, or building wings that “hover” over driveways or open space. These overhangs can twist or separate from the main structure during an earthquake if not properly braced.
Torsional stress from cantilevered designs often leads to damage at the connection points between the overhanging section and the main structure.
Common examples: Buildings with extended upper levels over carports or drop-offs, or second-floor expansions added after original construction.
4. Asymmetrical Layouts
Buildings with irregular shapes or uneven weight distribution can experience torsion or unbalanced movement in an earthquake. For example, if one side of the building is heavier due to added equipment or materials, it may twist unevenly during shaking.
Asymmetry also affects how seismic forces travel through the structure—potentially overwhelming particular walls or joints that weren’t designed to carry that load.
Common examples: Industrial facilities with heavy rooftop equipment, warehouses with unevenly distributed storage loads, or buildings with offset wings.
5. Discontinuous Shear Walls
Shear walls provide lateral stability by helping a building resist horizontal seismic forces. When these walls don’t align between floors—or are interrupted by large openings—they can’t effectively transfer force through the structure, creating weak points.
This condition is often unnoticeable until a building is inspected more closely, as the exterior may appear consistent while interior wall alignments tell a different story.
Common examples: Multi-story buildings with open atriums, elevator shafts that stop partway through the structure, or levels with extensive window walls.
Why Addressing These Risks Matters
Many of these seismic vulnerabilities exist in otherwise well-maintained, code-compliant buildings. But when an earthquake strikes, seismic design risks can be just as damaging as deferred maintenance—or worse.
A mid-year safety check offers property owners a proactive opportunity to:
- Identify structural red flags before they become liabilities
- Schedule retrofit planning outside of emergency timelines
- Align risk mitigation with long-term capital improvement budgets
- Maintain tenant trust and occupancy rates
Seismic Strength Starts with Awareness
Earthquake risk isn’t always obvious—and it’s not just building age. Layout, geometry, and structural irregularities can subtly impact how well your property performs when the ground shakes.
Earthquakes don’t follow a schedule. But your safety planning can. That’s why mid-year is a smart time to pause, reassess, and ask: Is my building truly ready?
At Saunders Seismic, we’ve spent decades helping commercial and industrial property owners identify these risks and reinforce their buildings with precision, care, and minimal tenant disruption. Whether you’re just starting to explore your options or responding to a recent engineering report, we’re here to make the path forward clear.
If your building includes any of the architectural features discussed in this article—or if you want a second opinion on potential seismic design risks—we can help you evaluate next steps with confidence.
Schedule a free consultation today.