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Inflation, rebuilding costs and underinsurance
Rebuilding costs rose nearly 30% in five years. How that leaves limits short, what research says drives underinsurance, and how to keep your limit current.
The cost of rebuilding a house has climbed faster than most dwelling limits were adjusted, so a policy that matched your home's rebuild cost a few years ago may not match it now. The Insurance Information Institute (Triple-I) reported in December 2025 that structural replacement costs had risen nearly 30% over five years. The gap between your limit and that cost is underinsurance, and it matters at the worst moment: after a total loss, when the policy pays no more than its limit.
How much rebuilding costs have risen
Triple-I's December 17, 2025 market release put the increase in structural replacement costs at nearly 30% over the previous five years, and named supply chain disruptions, higher material prices and workforce shortages as the causes. That is a national figure. Your market could be higher or lower, particularly if you live somewhere that a recent hurricane, hail season or wildfire has stretched local contractors.
The pressure has not stopped. The National Association of Home Builders reported on September 10, 2026 that building material prices, excluding energy, were up 5.1% from a year earlier in August 2026, and that inputs to residential construction overall were up 7.8% (NAHB Eye on Housing). Materials are only part of a rebuild; labor is often the larger share. building materials, labor shortages and claim costs covers both and tariffs and home insurance costs covers the trade policy piece.
Claims data show the same direction. According to Triple-I's tables of ISO data, average homeowners claim severity went from $13,884 in 2019 to $20,062 in 2023, and the average non-catastrophe fire claim from $99,613 in 2020 to $173,111 in 2024 (Triple-I). Severity mixes costs and loss types, so it is not a construction index, but it points the same way.
Why a fixed limit falls behind
An insurer sets your Coverage A limit from an estimate of what it would cost to rebuild, and then renews it every year. If the estimate at purchase was low, or if the annual adjustment trails the true local cost, the shortfall grows with each year of rising prices.
Two things happen when the limit is short. On a total loss, the policy pays the limit and no more, so you carry the difference. On a partial loss, the standard ISO HO-3 settles building losses at replacement cost only if the limit is at least 80% of the full replacement cost; below that, the payment is reduced under the formula in the form (HO 00 03 05 11; newer editions and your insurer's own form may differ). How much dwelling coverage do I need? walks through that formula, and the coinsurance and insurance-to-value calculator runs it with your numbers.
A hypothetical: five years of drift
Say you bought a house in 2021 with a $400,000 dwelling limit that matched the estimate then. If rebuilding costs in your market rose the 30% that Triple-I reported nationally, the same house now costs $520,000 to rebuild. Three ways it could have gone:
| Your limit today | Share of $520,000 | Total loss | $60,000 repair |
|---|---|---|---|
| $400,000, never adjusted | 77% | $120,000 short | Below the 80% line; the proportional formula gives about $57,700 before deductible, or the actual cash value of the damaged part if that is higher |
| $463,700, rose 3% a year | 89% | $56,300 short | Above 80%; paid in full |
| $520,000, matched to cost | 100% | Covered | Paid in full |
The middle row is the one many owners are in. An automatic increase keeps you above the 80% line without covering a total loss. The numbers are invented for illustration; a real market may have risen more or less.
Is inflation really the cause of underinsurance?
It is part of it, and researchers disagree about how much. Two recent studies point somewhere less comfortable.
Economists at the University of Colorado and the University of Wisconsin studied 4,859 policies affected by the December 2021 Marshall Fire in Colorado. They estimated that 74% of policyholders were underinsured, and 36% severely so, with a limit below three-quarters of replacement cost. The paper found that a sharp rise in rebuilding costs after the fire did not fully explain the shortfall, that older policies were no more or less underinsured than newer ones, and that average underinsurance differed widely from one insurer to another (Cookson, Gallagher and Mulder, Philadelphia Fed working paper 25-09, March 2025). A working paper is preliminary research and not a final finding.
A California Western School of Law professor, Kenneth Klein, analyzed 74,070 fire claims on owner-occupied California homes from 2018 to 2023. According to Insurance Business's September 2026 report on the study, 71.3% of destroyed homes had dwelling coverage below the insurer's own incurred loss, by an average of about 19%, and the point-of-sale rebuild estimate came in below the eventual loss 75% to 95% of the time. About 90% of the policies carried extended or guaranteed replacement cost, yet most catastrophe-destroyed homes still fell short. The study uses insurer-reported data and excludes flood, wind and FAIR Plan claims.
Read together, the two studies suggest that inflation widens the gap, but a limit set too low at the start, from the insurer's estimating tool, may be the larger problem. The other side of the argument, as insurers and agents usually frame it, is that construction costs move quickly, local conditions are hard to model, and an owner who declines a suggested increase or leaves out a renovation takes on part of the risk. There is truth in both, and the practical conclusion is the same. Do not assume the number on your declarations page was checked against anything but a model.
How your premium is tied to it
When a limit rises with construction costs, the premium rises with it, because the rate applies to a larger dollar amount. Part of a renewal increase can be a better-matched limit and not a higher rate. That is a trade worth making, and the way to tell the two apart is to ask your agent for the rate change and the limit change separately. See why homeowners insurance keeps going up for the other forces behind increases.
Insurers address drift in three ways:
- Inflation guard. A provision that raises the limit at renewal by a set percentage or a cost index. It keeps pace only as well as the index does; see inflation guard and automatic coverage increases.
- Periodic revaluation. Many insurers re-run their estimate every year or few years and propose a new limit at renewal. Accepting it is usually correct, unless you know the inputs are wrong.
- Extended or guaranteed replacement cost. Extra cushion above the limit, typically a stated percentage, or in some policies a commitment to rebuild. Triple-I describes the extra as 5 to 25 percent for extended replacement cost. A cushion helps but does not replace an accurate base; see extended and guaranteed replacement cost coverage.
Keeping your limit current
- Get the estimate and its inputs every year. Ask your insurer for the replacement cost figure and the list of features behind it: square footage, stories, finishes, roof, foundation.
- Check the inputs against the house. A finished basement, a remodeled kitchen, an addition or a swapped roof all change the cost. Tell your agent when you finish.
- Test the number locally. Run the home replacement cost estimator and, for a large home or a custom build, ask a local builder for a per-square-foot cost at your finish level.
- Compare the increase to what you have heard. If contractors in your area are quoting 8% more than a year ago and your limit rose 3%, ask for a higher limit.
- Recheck after a regional disaster. A hurricane, hailstorm or wildfire nearby can send labor prices up quickly, which insurers and contractors call demand surge.
- Consider the cushion. Ask whether extended or guaranteed replacement cost is available, what the percentage is, and what conditions attach to it.
- Know what to do if the limit proves short. If you discover after a loss that your coverage was not enough, underinsured after a disaster: your options lays out the options.
Key takeaways
- Triple-I reported in December 2025 that structural replacement costs rose nearly 30% in five years, and building material prices excluding energy were still up 5.1% year over year in August 2026 (NAHB).
- A dwelling limit that is never revisited drifts below the 80% line, and below the true cost, as prices rise.
- Research on the Marshall Fire and on California fire claims suggests that low starting estimates and insurer-to-insurer differences matter at least as much as inflation.
- Part of a premium increase can be a limit that now matches the rebuild cost, which is a reason to ask for the rate and limit changes separately.
- Review the estimate and its inputs each year, update after renovations, and treat inflation guard and extended replacement cost as cushions, not fixes.