Earthquakes and Building Codes

Why most earthquake deaths are caused by collapsing buildings, how building codes save lives, and why enforcement is the hard part.

Earthquakes cannot be prevented or precisely predicted. But how many people they kill depends largely on how buildings are built. Engineers often say that earthquakes don’t kill people; collapsing buildings do.

Building codes

A building code sets minimum standards for construction, such as the strength of materials, the design of columns and beams, and how buildings are anchored. Seismic codes are designed so buildings can withstand strong shaking without collapsing, even if they are damaged.

Countries in earthquake zones, such as Japan, Chile, New Zealand and the United States, have developed strict seismic codes, often improving them after each major earthquake.

The enforcement problem

Having a good code on paper is not enough. It must be enforced. When builders cut corners to save money, using weaker concrete or fewer steel reinforcing bars, buildings may look fine but collapse in an earthquake.

In February 2023, powerful earthquakes struck southern Türkiye and northern Syria, killing more than 50,000 people. Türkiye had modern building codes, but many buildings that collapsed were found not to meet them. Past construction amnesties, which let owners legalise buildings that broke the rules by paying a fee, were widely criticised afterwards.

The economics of cutting corners

Why do builders and owners skip safety? The cost of strong construction is paid now and is visible; the benefit arrives only if a rare earthquake strikes, perhaps decades later. Buyers often cannot tell how well a building was made, a problem of hidden quality. And inspectors may be underpaid or open to bribes. Research has linked corruption to higher earthquake death tolls.

Two apartment blocks

Two similar apartment blocks are built side by side. One follows the code, costing somewhat more. The other skips reinforcement to save money, and the savings go to the developer. For years, residents cannot tell the difference. When a strong earthquake strikes, the first is damaged but stands; the second collapses. The saving was small; the cost was catastrophic.

Retrofitting

Older buildings built before modern codes can be retrofitted, strengthened with extra supports. Retrofitting is expensive, so governments often focus on schools, hospitals and emergency buildings first. Some cities, like Los Angeles, require owners of certain vulnerable building types to retrofit.

Thinking strong codes guarantee safety

Codes only protect people if builders follow them and inspectors check. Enforcement, honest inspection and penalties for violations are as important as the rules themselves.

Key takeaways

Most earthquake deaths are caused by collapsing buildings.
Building codes set standards so buildings withstand strong shaking.
The 2023 Türkiye-Syria earthquakes showed the deadly cost of poor enforcement.
Hidden quality, short-term thinking and corruption lead builders to cut corners.