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Earthquake risk is underpriced: why Seattle and the West Coast rank so high

PropHunt Team7 min read

Earthquake is the hazard most likely to be missing from your model entirely — and that is exactly why it is dangerous. It is low frequency and high severity, standard property policies exclude it, and a major event does not appear in a five-year hold projection. So investors treat it as a tail they will never see. The carriers do not, and neither should you.

The data

Why the West Coast ranks so high

On FEMA's National Risk Index, the top-percentile earthquake metros are Los Angeles (100), San Jose (99.9), Seattle (99.9), and San Francisco. Seattle is the instructive one: it lands in the national top-10 for overall risk almost entirely on seismic exposure. The USGS National Seismic Hazard Model maps why — the Pacific Northwest sits over the Cascadia subduction zone, capable of a magnitude-9 event, while California rides the San Andreas system.

The mechanism

Excluded by default, expensive to add

Because standard commercial property policies exclude earthquake, the cost shows up in one of two places: a separate earthquake (DIC) policywith a high deductible — commonly 10–20% of insured value — or, if you skip it, uninsured tail risk sitting on your balance sheet. Both are real costs; pretending the second one is zero is how a single event wipes the equity in a levered deal.

Lenders increasingly force the question. Many require a seismic risk assessment — a Probable Maximum Loss (PML)study — on assets in high-seismic zones, and will require earthquake coverage above a PML threshold (often around 20%). If you have not priced that into the deal, the lender will price it for you, after you are committed.

The takeaway

The right way to carry earthquake in a West Coast pro forma is not a line item of zero. It is either an explicit DIC premium with its deductible modeled, or an explicit, quantified decision to self-insure the tail — ideally informed by a PML study. “We'll deal with it later” is not an underwriting position.

The diligence checklist

What to verify before you offer in a seismic market

  • Pull the seismic hazardfor the address (USGS) and the building's construction type — unreinforced masonry and soft-story buildings carry far higher loss potential.
  • Order or review a PML study. It drives both your insurance requirement and your real exposure.
  • Get a DIC quote with the deductible spelled out, and decide explicitly whether to buy it or self-insure.
  • Check retrofit status and local mandates. Cities like Los Angeles and San Francisco have mandatory retrofit ordinances; un-retrofitted buildings can be both a liability and a capex surprise.

Earthquake is the clearest case of the broader theme — insurance as the swing variable — but it sits alongside wildfire and flood in the markets that rank highest overall. See the full picture in the riskiest-metros ranking or browse any market on the Risk Index.

Check seismic + insurance exposure on any address

The free Deal Scan returns the earthquake score and the broader hazard / insurance read for a specific property, with the cap rate and comps — so the tail risk is in the model, not a surprise after the lender's PML study.