Damaging quakes are not just a West Coast problem
Most buyers file earthquakes under California and stop there. The hazard map is wider than that. The USGS 2023 National Seismic Hazard Model estimates that close to three quarters of the United States could experience damaging shaking, and the places where risk is most underappreciated are usually the ones without the shaking baked into their building codes.
- The New Madrid Seismic Zone, spanning parts of Missouri, Tennessee, Arkansas, and Kentucky, produced three magnitude 7 events in 1811 and 1812 that rang church bells in Boston. Big quakes there are rare, on the order of centuries, which is exactly why the housing stock was never built for them.
- Oklahoma and parts of Kansas saw earthquakes jump from a couple a year to several a day during the 2010s, driven by wastewater injection, capped by a magnitude 5.8 near Pawnee in 2016.
- The Wasatch Fault runs straight through Utah's most densely populated corridor, and researchers put the chance of a magnitude 6.75 or larger in the next 50 years at roughly 43%.
- The Pacific Northwest and coastal British Columbia sit above the Cascadia subduction zone, the source of the region's largest possible quake.
The point is not to scare anyone off a region. It is that a buyer in Memphis or Salt Lake City has as much reason to look at this as a buyer in Los Angeles, and far fewer people around them are talking about it.
How to read a property's earthquake risk before you offer
Two free steps, before you ever book a showing.
First, check the ground. The USGS hazard maps and your state geological survey will tell you the shaking potential and whether the parcel sits near a mapped fault, a liquefaction zone, or soft soil that amplifies a quake. In California, sellers must provide a Natural Hazard Disclosure that flags seismic and other hazards, so read it closely rather than skimming past it.
Second, read the house. This is Casaroo's whole method: the expensive risks hide in the photos most buyers scroll past. A listing sells the looks. What decides how a home rides out a quake is the bones, the structure and the systems, and those show up in the exterior shots, the basement photos, and the ones the listing quietly left out. Pair the hazard map (the seismologist's half) with a careful read of the structure (the buyer's half) and you can size up a home's earthquake exposure before you write an offer.
The warning signs that show up in the photos
These are the features most associated with earthquake damage in wood-frame houses, and most of them are visible before an inspector ever arrives.
- An unreinforced masonry chimney. A tall brick stack with no visible bracing is one of the first things to fail in a quake, and it often shows clearly in exterior photos.
- A cripple wall or soft story. A short wood-framed wall between the foundation and the first floor, or living space and garage doors stacked over an open lower level, is a classic collapse pattern. Look at the front elevation.
- Foundation cracks, and which kind. Thin vertical hairlines are usually harmless shrinkage. Horizontal cracks, bowing walls, or stair-step cracks can mean active movement, and shaking punishes a foundation that is already compromised. Telling them apart reliably needs a structural engineer, not a waterproofing salesperson. See foundation cracks.
- Brick or stone veneer over wood framing, which can shed in a quake if it was not properly tied back.
- A water heater that is not strapped. It is a cheap fix, but an unstrapped tank can topple and shear its gas line, and it tells you whether anyone ever did the basic seismic prep.
The damage buyers overlook most
Buyers fixate on the finishes, the kitchen and the paint, and miss the parts a quake actually goes after. The overlooked damage is almost never the pretty stuff. It is the chimney, the foundation and cripple walls, the gas connections, and the pre-existing weaknesses that shaking simply exposes. Brittle old plumbing and marginal electrical do not survive movement well, so a quake often turns a problem you could have seen into a repair you cannot avoid.
This is the core idea behind scoring a home's bones separately from its looks. The looks are what get staged for the photos. The bones are what cost real money, and in a seismic region they are also what keep you safe.
Retrofits, and what they do for value and insurance
The most common fix for an older wood-frame house is a foundation retrofit: bolting the frame of the house to its foundation and bracing the cripple walls in the crawl space with plywood. It is not exotic work.
In California, the Earthquake Brace + Bolt program offers eligible owners a grant of up to $3,000 toward a code-compliant retrofit, and income-eligible households can reach up to $10,000 with the CEA supplemental. A typical brace-and-bolt retrofit runs about $3,000 to $7,000. Eligibility generally targets homes built before 1980 with a raised foundation and a crawl space, in higher-hazard ZIP codes.
For a buyer, a documented retrofit does two things. It reduces the odds of the most expensive structural damage, and it can lower an earthquake insurance premium, since insurers like the California Earthquake Authority offer a hazard-reduction discount for a verified retrofit. Ask whether the home has been retrofitted, and get the paperwork. If it has not, price the retrofit into your offer the same way you would a roof near end of life.
Earthquake insurance is a separate policy, and the deductible is the surprise
Here is the part that catches people. A standard homeowners policy does not cover earthquake damage. Anywhere in the U.S., earthquake coverage is a separate policy or endorsement you have to buy on purpose.
Almost nobody does. Even in California, only about one in eight homeowners carries earthquake insurance, which means most people in a high-hazard state are self-insuring a catastrophe without realizing it.
And when buyers do get a policy, the deductible is the shock. Earthquake deductibles are not a flat dollar figure. They are a percentage of the insured value of the dwelling, commonly 5%, 10%, 15%, 20%, or 25%. On a $500,000 home, a 15% deductible means the first $75,000 of damage is on you before the policy pays a cent. That is the number to understand before you buy coverage, not after. Evaluate the deductible, what is and is not covered (many policies limit or exclude the contents, the pool, or masonry veneer), and whether a retrofit earns you a discount.
Does living in an earthquake zone make financial sense?
For most buyers in these regions, the answer is yes, with eyes open. Whole economies sit on top of active faults, and walking away from every seismic ZIP code is neither realistic nor necessary. The mistake is not buying in a quake zone. It is buying blind, treating a low listing price as a bargain without pricing in the retrofit you will want and the insurance you should carry.
A smarter first look turns earthquake risk from a vague fear into a line item. What does the ground map say. Is the chimney unreinforced. Is the foundation bolted. What would a retrofit cost, and what would coverage cost with a deductible you can actually absorb. Answer those before you remove your conditions, and an earthquake zone becomes a place you buy on purpose, at a price that reflects reality.
One cross-border note: this all ports north. In British Columbia and the rest of Cascadia, earthquake coverage is likewise an optional add-on that most owners skip, and the same read-the-structure logic applies.
What to do with an earthquake flag
A flag is not a signal to walk. It is a question and a number. Confirm the structural questions with a licensed engineer, get a retrofit quote, price coverage with a real deductible, and negotiate from there. That is the entire point of a smarter first look. For the flags that cross regions, see red flags in a listing, and for the specific ones, foundation cracks and chimney and flue risks.