Does Your House Need Earthquake Retrofitting? Here’s How to Tell

If you live in an earthquake-prone area like the Pacific Northwest, making sure your home is earthquake-ready is more than smart—it could save lives. Earthquake retrofitting strengthens your home’s foundation and structural elements to better withstand shaking. But how do you know if your house needs it?

Here’s how to assess your home—and what steps to take if a retrofit is in order.

1. Know When Your House Was Built

The age of your home is one of the biggest indicators of seismic vulnerability. If your house was built before the mid-1970s, there’s a good chance it was not constructed with modern seismic safety in mind.

• Homes built before 1985 in places like Seattle likely lack anchor bolts, bracing, or proper connection between the wood framing and the foundation.

• Newer homes generally follow updated seismic building codes and are better equipped to resist earthquakes.

🛠️ Check building records or your permit history if you’re unsure. Your local building department may have this information.

2. Look at the Foundation and Crawl Space

If your house has a raised foundation with a crawl space, it may be vulnerable to sliding off the foundation during a quake. This is especially true if:

• The wood frame isn’t bolted to the concrete foundation.

• The short walls (called cripple walls) between the foundation and the floor are not braced with plywood or OSB.

• There are signs of rot, poor-quality concrete, or previous shifting.

You can often spot these issues by removing a vent cover or access panel to inspect your crawl space. Or, better yet, hire a qualified inspector.

📖 Learn more in the Earthquake Brace + Bolt Homeowner Resources.

3. Check for Unreinforced Masonry

If your home has brick or stone walls without steel reinforcement, it may be an unreinforced masonry building (URM)—one of the most dangerous types during an earthquake. Telltale signs include:

• Bricks laid in a decorative pattern without visible metal ties.

• Cracking in mortar joints.

• Lack of interior reinforcement.

URM buildings are particularly vulnerable and may even be flagged for mandatory retrofitting in some jurisdictions (like Seattle’s URM policy).

4. Look for Additions or Remodels

Homes with multiple remodels or add-ons might not be structurally unified. For example:

• A second-story addition added decades after original construction.

• Converted garages or sunrooms without proper lateral bracing.

If parts of your home were added without seismic reinforcement, they may fail independently during shaking.

🧰 A licensed structural engineer can assess whether different parts of your house move uniformly or need additional anchoring.

5. Signs You’ve Already Had a Seismic Weakness

Even if you haven’t experienced a major earthquake, there may be hints your house isn’t solidly anchored:

• Uneven floors or cracks in the walls.

• Doors and windows that don’t close properly.

• Cracks along the foundation.

While not always caused by seismic activity, these can indicate foundation movement—something to take seriously in a high-risk zone.

So, Does Your House Need a Retrofit?

If your home checks any of these boxes:

✅ Built before 1985

✅ Raised foundation with an unbraced cripple wall

✅ Unreinforced masonry

✅ Evidence of past shifting or poor connections

...you should seriously consider a retrofit.

The good news? Retrofitting doesn’t always mean a full rebuild. For many homes, it involves:

• Bolting the frame to the foundation

• Bracing cripple walls

• Adding hardware to strengthen connections

Next Steps

Hire a retrofit specialist like Stronghome Seismic to evaluate your home.

🧭 FEMA’s Homeowner’s Guide to Earthquake Safety (PDF) is a great starting point for DIY evaluation and planning.

By understanding the vulnerabilities in your home and taking proactive steps, you’ll not only protect your investment—you’ll safeguard your family in the event of the next big quake.