Electrical fires: the #1 identified cause of US home fire property loss.

Two ways of ranking home fire damage produce two different answers. By count, cooking is the leading cause: it starts roughly half of all US home fires. By total dollar loss, electrical malfunction destroys more home value than any other identified ignition mechanism. The headline claim on this page is the second one.

• Leading by total dollar loss.Across the US residential building fire data, electrical malfunction tops the leaderboard of named causes for total annual dollar loss [1].
• Leading by per-fire severity.Among the same named causes, electrical fires also produce the highest average dollar loss per fire (~$63,000), about 18 times a cooking fire and roughly 3.6 times a heating fire [1][3][4][5].
• Not leading by ignition count.Cooking starts about 7 times more residential fires than electrical malfunction each year. Most cooking fires are caught small and produce little dollar loss [4].

One scoping caveat: 'other unintentional, careless'

USFA tracks an aggregated catch-all category called other unintentional, careless. It bundles many small residual causes (candles knocked over, child playing with fire, miscellaneous accidents) and in 2023 it carried higher total dollar loss than electrical ($2.48B vs $1.50B) [1]. Because it is a residual bucket and not a single ignition mechanism, the precise headline claim defended here is leading identified cause, i.e. leading among the specific named ignition mechanisms (cooking, heating, electrical malfunction, smoking, open flame, intentional, exposure, natural, other heat). On that comparison, electrical is #1.

The numbers below are taken directly from the US Fire Administration's 2023 residential building fire dollar-loss table ^[1], paired with the fire counts from the corresponding cause pages where available [2][3][4][5]. The per-fire column is the division.

Among the eight named ignition mechanisms, electrical malfunction leads on total dollar loss. It is also the only named mechanism that crosses $1B in a single year. The other unintentional, careless row sits above it in aggregate, with the caveat noted in section 01.

The per-fire severity gap is intuitive once you look at where and when the fires start.

• Cooking fires start in front of someone.Roughly half of all home fires begin on the stovetop or in the oven, where an occupant is usually present, awake, and looking at the heat source. Most are extinguished or contained in the first minute.
• Electrical fires start where no one is looking.Behind walls, in roof spaces, inside outlets and switchboards, at appliance cords trailing under furniture. By the time the smoke alarm sounds, the fire has often had time to compromise structural materials.
• Detection lags propagation.An arc fault can smoulder for minutes inside a wall cavity before producing detectable smoke. By the time anyone notices, the damage envelope is wider.

The cooking-vs-electrical asymmetry is a structural feature of how each cause behaves, not a statistical accident. The same gap appears every year of the 10-year USFA dataset [1].

Comparing 2014 to 2023, USFA reports the following for residential electrical malfunction fires ^[2]:

• Fire count.+2% over the decade. Electrical fire frequency is roughly flat.
• Civilian deaths.-19%. Smoke alarm coverage and faster response are pulling fatalities down.
• Dollar loss.+28%. Per-fire severity is increasing materially.

NZ has no equivalent NFIRS-grade per-cause residential fire dollar-loss dataset, so we cannot quote a like-for-like New Zealand figure. What we can say is that the wiring physics and product mix are the same: AS/NZS 3000 covers the same circuit types, NZ homes have the same heat pumps and EV chargers, and FENZ structure-fire counts show electrical as a leading cause locally.

• 2,378.House fires in New Zealand in 2025. 15 of them fatal [8].
• 830 of 2,432.Structure fires attributed to electrical causes in 2023, a 34% increase year on year [7].
• Older stock disproportionately exposed.BRANZ research indicates pre-1980 NZ dwellings carry a disproportionate share of the electrical fire burden, consistent with the US severity-with-aging-infrastructure pattern.

Cooking fires are won at the cooktop. Electrical fires are won at the panel. The protective gap on a default NZ switchboard sits exactly where the per-fire severity is highest.

• Arc-fault detection per circuit.Catches the ignition mechanism behind roughly two thirds of home electrical fires before it propagates. See arc-fault-risk.
• Temperature-monitored modules.Detects switchboard overheating and opens the affected circuit before plastics ignite. Switchboard fires are a recognised subset of the electrical category.
• Hardened enclosure.Fire-resistant foam and fire-rated plastic housing reduce the spread envelope if a fault does ignite inside the panel.
• Continuous self-test.Every circuit, constantly. The protection chain is continuously verified and issues are flagged, not relying on a 6-monthly push button that almost no homeowner runs. See rcd-thresholds.