High-value home policies increasingly carry a deductible that reads as trivial: one percent. It glides past in the declarations, a small round number. Then the arithmetic arrives. One percent of what? Of the dwelling limit, and on a home the carrier values at $8 million, that is an $80,000 deductible, applied to water damage, the single most frequent category of homeowners loss. The household that believed itself insured against the common claim discovers it is insured only against the uncommon one.
Percentage deductibles migrated into personal lines from catastrophe zones, where hurricane and wind deductibles of two to five percent became standard coastal practice. Their logic in catastrophe lines is at least coherent: they scale the insured’s retention to the property’s value and reduce the carrier’s exposure to correlated event losses. Their migration into water coverage, a frequency peril rather than a catastrophe peril, serves the carrier differently: it removes from the policy the ordinary losses, the supply-line failures, appliance leaks, and water-intrusion claims that constitute the bulk of homeowners claim counts, while preserving the appearance of full coverage.
Three features make these provisions treacherous. First, the percentage applies to the dwelling limit, not to the loss, so the retention grows with the carrier’s own valuation of the home, including the upward revaluations that follow inspection. Second, water damage is precisely the loss most households will actually have; the deductible transfers back the most probable claim. Third, the provision is easy to miss. It sits among percentages and definitions, and nothing in the premium invoice announces its significance.
The remedies are negotiable more often than clients expect. Some carriers will buy the percentage deductible down to a flat amount for additional premium. Others offer water-damage sublimits or endorsements that restructure the retention. A competing carrier may simply not impose it. The exercise that matters is translation: converting every deductible on the policy from its stated form into dollars, peril by peril, before binding. One percent is not a number a household can evaluate; $80,000 is. Insurance is only understood in the currency in which losses are paid.
This article is adapted from Nathan’s original LinkedIn post, published June 20, 2025. Read the original post on LinkedIn →