Flood and earthquake insurance, written for multifamily.

Both covers exist because the standard property form wants nothing to do with either peril. Flood and earthquake are catastrophic, correlated, and hard to diversify, so carriers carved them out decades ago. What you buy to replace them is either a government program, a specialty private policy, or both stacked.

What flood actually means on an insurance policy

Flood has a specific definition, and it is narrower than “water damage.” Flood is rising water from outside: storm surge pushed ashore by a hurricane, a bayou or river coming out of its banks, sheet flow from heavy rain that inundates the ground and enters the building, and mudflow. The test is rising, surface, and from outside the structure. A hurricane that drops twenty inches of rain and floods your first-floor units is a flood loss. The same hurricane tearing the roof off and letting rain in from above is a wind loss. Same storm, two different policies, and the second one does not exist unless you bought it.

The distinction owners most often get backwards: a burst pipe, a failed water heater, or a sprinkler discharge is not flood. That is water damage, and it is covered under your standard property policy. Owners who have had a plumbing loss paid sometimes conclude they “already have flood coverage.” They do not. Interior water from the building’s own systems is one peril. Rising water from the street is another, and only a flood policy responds to it.

NFIP versus private flood

The National Flood Insurance Program is the federal backstop, and it is where most lender-required flood placements start. Two of its features drive every multifamily flood conversation. First, the limits: the NFIP building limit available to an apartment community is capped well below the replacement cost of almost any multifamily asset, currently in the hundreds of thousands per building. It is a floor, not a solution. Second, the timing: NFIP policies normally carry a 30-day waiting period before coverage takes effect, with a narrow exception tied to loan closings.

Private flood is written by commercial carriers outside the federal program. It can carry limits up to full replacement cost, it can include loss of rents (which the NFIP generally does not), its waiting periods are often shorter or waived, and in many Texas and Florida markets it prices competitively against the NFIP for well-elevated risks. Lenders accept private flood as long as it meets the regulatory definition, which mainstream private policies do. The practical structure on a larger asset is often layered: NFIP or a private primary at the base, with excess flood above it to reach the value the lender wants insured.

Earthquake and earth movement

The property policy excludes earth movement broadly: earthquakes, landslides, sinkholes, subsidence, settling. Earthquake coverage buys back the seismic part of that exclusion, typically defined as earth shock, including aftershocks within a stated window (often 72 to 168 hours, with all shocks in the window treated as one event subject to one deductible). The cover responds to shaking damage to the building, and on multifamily that means foundation and structural damage, masonry and veneer failure, and the contents you own.

Two things make earthquake different from every other cover on your schedule. The deductible is a percentage of insured value, not of the loss, and the percentages run higher than wind. And the exclusion it sits on is wider than people think: settling, expansive soils, and sinkhole activity are earth movement too, and they are excluded whether or not anyone would call the event an earthquake. In Florida, sinkhole and catastrophic ground cover collapse have their own statutory treatment and their own endorsements. In parts of Texas, foundation movement from expansive clay is a maintenance reality, not a covered claim. Know which earth movement your policy actually bought back.

Loss of rents on these policies

A flood that takes forty ground-floor units out of service for nine months is an income event as much as a construction event. The NFIP generally does not cover loss of rents on an apartment building. Private flood can, and on an income-producing asset it should. The same question applies to earthquake: business income is available but not automatic, and the indemnity period has to reflect a real rebuild timeline. If your flood and earthquake placements cover the structure but not the rent roll, you have insured the asset and left the debt service exposed.

Flood is the most regulated corner of lender insurance requirements. Federal lending rules make some of it mandatory, and the loan documents handle the rest. Earthquake sits in a different place: driven by the lender’s catastrophe modeling rather than statute.

Mandatory purchase in special flood hazard areas

If any building securing the loan sits in a special flood hazard area (the A and V zones on FEMA maps), a federally regulated lender must require flood insurance as a condition of the loan. No zone, no requirement; but the determination runs against the building, not the parcel, so one low building on a large site can trigger the requirement for the loan. The requirement follows the loan for its entire life through zone tracking, which is why remapping matters.

Limits above the NFIP cap

The statutory minimum is the lesser of replacement cost, the loan balance, or the NFIP maximum. On a multifamily asset the NFIP maximum usually binds first, and sophisticated lenders know it. Many loan documents now require flood limits at full insurable value, which means private flood or an excess layer above the NFIP. Confirm the required limit before you place the base layer, because the cheapest compliant placement and the placement your loan documents actually require are often different things.

Deductible caps and waiting-period logistics

Lenders cap flood deductibles the same way they cap wind, and the certificate has to show coverage in force at closing, not coverage that starts in thirty days. Both are checkable weeks early, and both surface the week of closing when nobody checked. Our Lender Liaisons spend a real share of their time on exactly these two lines of the requirements schedule.

Earthquake and the PML study

In seismically exposed markets, larger loans routinely come with a probable maximum loss study: an engineering estimate of the damage a design-level earthquake would do to the collateral. The PML drives whether the lender requires earthquake coverage and at what limit. This rarely binds a Texas or Florida deal, but owners with nationwide portfolios will meet it, and the time to price earthquake is before the term sheet makes it a condition, not after.

Flood and earthquake are the two most model-driven lines in the program. The rating variables are mostly physical facts about the site and the structure, which means the price is largely knowable before you buy, and a few of the variables are things an owner can actually change.

Zone and base flood elevation

For flood, the map is the starting point: the zone designation and the base flood elevation, the computed height floodwater is expected to reach in a 1% annual-chance event. Everything else in flood rating is measured relative to that line. Two buildings a street apart can sit in different zones with different base elevations and price nothing alike.

First-floor height and the elevation certificate

The single most powerful rating variable is where the lowest floor sits relative to base flood elevation. Above it, the rate falls; below it, the rate climbs fast. The document that proves it is the elevation certificate, a surveyor’s measurement of the building’s floor heights. On garden-style multifamily, an elevation certificate is often the difference between a punitive rate and a reasonable one, and owners who skip it get rated on assumptions that are rarely in their favor.

Construction, enclosures, and flood openings

What sits at ground level matters. Enclosed areas below the lowest floor, parking under the building, storage rooms, ground-floor units versus elevated first floors: each changes the exposure. Engineered flood openings that let water flow through an enclosure instead of building pressure against it are a real mitigation with a real rating effect. So is moving mechanical equipment above the base flood elevation, which is one of the few flood mitigations a value-add renovation can deliver.

Distance to coast and surge modeling

Private flood carriers price with their own catastrophe models, and in Texas and Florida those models care about storm surge as much as river flood. Distance to coast, elevation of the site, and the surrounding terrain feed the number. This is why private flood quotes can disagree with the NFIP by a wide margin in either direction: they are not rating the same risk the same way.

Earthquake: construction class, soil, and proximity to fault

Earthquake rating turns on how the building behaves when the ground moves. Frame construction flexes; unreinforced masonry does not. Soft soils amplify shaking. Proximity to mapped faults sets the baseline hazard, and retrofits (bolted foundations, shear walls, soft-story reinforcement) earn credit. The deductible is the other lever: raising the percentage lowers the premium, but remember what the percentage applies to. It is insured value, not the size of your claim.

Deductible structure moves everything

On both lines, the deductible decision is the price decision. A higher percentage deductible can cut premium meaningfully, and on a large schedule it also moves real money into your retention. Price a couple of structures before you decide, in dollars, the way you would model any other self-insured layer.