Methodology and sources

The rule behind every figure

We only publish figures we can tie to a named public source, with source name, source year, and verified date stored in our checked-in data file (src/data/state-costs.json) and printed in the source box on every state page. Launch verification date: 2026-10-04. If a source is revised, we update the figure, the year and the verified date together.

Primary sources at launch

• State averages: Bankrate True Cost of Home Insurance 2025 state table (as reproduced by The Hartford, citing Bankrate), priced on a $300,000 dwelling coverage basis. That basis is stated on every page that uses the figures.
• National average: $2,470 per year from the Bankrate True Cost of Home Insurance report (press release, August 25, 2025).
• Trend context: an Insurance Information Institute summary of NAIC data noting the average homeowners premium rose 11.2 percent in 2022 (NAIC study reported May 2025, latest cited by III). We cite this as direction, never mixed into the state averages.
• Median home values: Ruby Home 2023 median home price summary, used for context only. Insurers price rebuilding cost, not resale value, and our pages keep the two visibly separate.

States included and excluded

The launch table covers 12 states where we verified the published figure: California, Texas, Florida, New York, Pennsylvania, Illinois, Ohio, Georgia, North Carolina, Michigan, New Jersey and Virginia. Where a state figure cannot be verified, we show the national benchmark and say so, or exclude the state. No insurer rankings are presented as advice anywhere on this site.

The benchmark model, in the open

The Home Cover Benchmark starts from the published state average and applies simple factors printed on the tool page: dwelling band $300k at 1.0, $500k at 1.35, $750k at 1.7; roof age 0-10 years at 0.95, 10-20 at 1.0, 20+ at 1.2, unknown at 1.35; deductible $1,000 at 1.0, $2,500 at 0.93, 1% at 0.97, 2% at 0.9. The range shown is 80% to 125% of the adjusted centre. These factors are a transparent teaching model, not an insurer rate filing, and the tool labels its output a benchmark range, not a quote.

Known limitations

• Published averages describe groups in a past period. Your premium will differ, sometimes widely.
• The $300,000 dwelling basis frames every state comparison. Higher limits are translated with the printed factors, not re-measured.
• Flood insurance is excluded from every figure. It is a separate policy with its own pricing.
• Median home values are 2023 summary figures used for context, not for pricing.