According to the Institute for the Catastrophic Loss Reduction:

Older wood-frame homes can be especially vulnerable during earthquakes when the structure is not adequately connected to its foundation.

About 1 million British Columbians live in approximately 440,000 homes that may be vulnerable to this type of earthquake damage. A relatively simple seismic retrofit known as brace + bolts can significantly strengthen these homes.

Why older homes are vulnerable

Many older wood buildings have weak walls between the foundation and first floor. Some also lack bolts connecting the wood structure to the foundation.

During strong earthquake shaking, these weaknesses can allow a home to move off its foundation or collapse. Damage can exceed $100,000, and residents may be displaced from their homes.

A practical retrofit solution

An earthquake brace + bolts retrofit strengthens the connection between the home and its foundation.

The retrofit typically involves:

  • Anchoring the wood structure to the foundation
  • Strengthening the short walls between the foundation and first floor
  • Improving structural connections so the home responds more effectively during earthquake shaking

A contractor can install the retrofit using established standard drawings, with an estimated cost of approximately $5,000 to $10,000.

Benefits beyond the individual home

Strengthening older homes can benefit entire communities.

Research cited in the fact sheet estimates that society can receive up to $8 in benefits for every $1 invested in strengthening vulnerable wood-frame buildings. Benefits can include reduced displacement, lower recovery costs, greater housing stability and reduced economic disruption after a major earthquake.

Proven elsewhere

Similar programs have already been implemented at scale in California, where tens of thousands of homeowners have completed seismic retrofits.

The experience demonstrates that brace + bolts is a well-understood approach that can be implemented broadly to improve residential earthquake resilience.

Learn more about earthquake brace + bolts retrofits

Read the full fact sheet to learn more about the risk, the retrofit approach and the research supporting residential seismic upgrades.

Download the Fact Sheet