Topical Fire reporT SerieS Volume 8, Issue 2 / March 2008

Residential Building 

Electrical Fires

These short topical reports are designed to explore 

facets of the U.S. fire problem as depicted through 

data collected in USFA’s National Fire Incident 

Reporting System (NFIRS). Each topical report 

briefly addresses the nature of the specific fire or 

fire-related topic, highlights important findings 

from the data, and may suggest other resources to 

consider for further information. Also included are 

recent examples of fire incidents that demonstrate 

some of the issues addressed in the report or that 

put the report topic in context.

Findings

■ Annually, an estimated 28,300 residential building electrical fires cause 360 

deaths, 1,000 injuries, and $995 million in direct loss.

■ Fifteen percent of residential building electrical fires start in bedrooms.

■ Nearly half (47%) of the residential building electrical fires where equipment 

was involved were caused by the building’s wiring.

■ Twenty-two percent of residential building electrical fires occur during 

December and January.

continued on next page

Electricity is a basic part of residential life in the United 

States. It provides the energy for most powered items 

in a contemporary home, from lights to heating systems to 

televisions. Today it is hard to imagine a residence without 

electricity. It is a part of our homes and our activities that 

most of us take for granted. We rarely think how powerful 

electricity is.

Yet, using electricity can have dangerous consequences. 

Electrical fires are pervasive throughout the United States, 

causing injury, claiming lives, and resulting in large losses 

of property. Faulty electrical systems cause many fires. Even 

more electrical fires result from inappropriate wiring installations, overloaded circuits, and extension cords. Based 

on the latest available data for 2003 to 2005, an estimated 

28,300 residential building electrical fires occur annually 

and cause 360 deaths, 1,000 injuries, and losses of $995 

million.1,2,3 Electrical fires accounted for 7% of all residential building fires in this 3-year period.

Fire Rates Attributed to Residential 

Electrical Building Fires

Electrical fires in residential buildings result in more damage and higher death rates per 1,000 fires on average than 

nonelectrical residential fires (Table 1). Dollar loss per fire 

for residential building electrical fires is more than double 

that for nonelectrical residential building fires; deaths per 

1,000 fires is about 70% higher for residential building 

electrical fires. The injury rates resulting from residential 

building electrical and nonelectrical fires, however, are 

roughly the same, at 28 to 29 injuries per 1,000 fires.

Table 1. Loss Measures for Residential 

Building Electrical Fires 

(3-year average, 2003-2005).

Loss Measure

Residential 

Building Electrical 

Fires

All Nonelectrical 

Residential Building 

Fire Causes

Loss per fire $25,126 $10,635

Injuries per 1,000 fires 28.5 28.2

Deaths per 1,000 fires 6.3 3.7

Source: NFIRS 5.0

Note: Loss per fire is computed only for those fires where loss and cause information was available.

The Electrical Fire Problem

Despite their prevalence, electrical fires are not always noted 

as such. When fire is severe, it can be difficult, for example, 

to discern whether an electric appliance started the fire or if 

a poorly wired plug was the cause. Heat-producing electrical equipment (e.g., hair dryers, portable heaters, cooking 

U.S. Department of Homeland Security • U.S. Fire Administration

National Fire Data Center • Emmitsburg, Maryland 21727

www.usfa.dhs.gov/statistics/reports/index.shtm
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 2

continued on next page

appliances, and the like) tend to use more power than 

other electrical equipment. Devices like these may overload 

a circuit, especially one that is already reaching its maximum 

amperage allowance. Coupled with a faulty circuit breaker, 

this overload can cause the products to overheat and possibly 

to catch fire. Moreover, electrical fires that start in walls can 

smolder for some time. By the time the fire is detected, most 

likely it already has spread within the walls, unseen. There 

are over three times more residential building electrical fires 

than nonresidential building electrical fires, so the problem is 

particularly important for each of us in our homes.

Electrical fires can be particularly tricky to put out. Since 

they involve electricity, and water conducts electricity, using 

water to put out the fire can cause electrocution. Chemical 

powders can cause the fire to smolder rather than extinguish, setting the stage to reignite. Turning power off to the 

residence is an important step, if it is possible to do so.

While new construction is not immune from electrical 

fires caused by faulty wiring, there are many older homes 

with outdated wiring that is deteriorating, inappropriately 

amended, or insufficient for the electrical loads of a typical 

household in the 21st Century.

According to Underwriters Laboratories (UL), over 30 million homes—more than one-third of all U.S. housing—are 

more than 50 years old.4

 Consider the expansion in the 

number of appliances used by residents in the past halfcentury, and it is quickly obvious that overloaded wiring 

and circuitry is likely in these structures. Overloading will 

heat up wiring that already could be deteriorating, crumbling, and no longer a good insulator.

Just how big this problem is remains to be seen. The 

Residential Electrical System Aging Research project was 

launched by the Fire Protection Research Foundation to 

study how the age of wiring, outlets, junctions, and other 

connectors affects the pattern of electrical fires in homes.5,6

One objective of the study is to make improvements to the 

National Electrical Code® (NEC) (National Fire Protection 

Association (NFPA) 70) and through the building codes 

adopted by local and State jurisdictions around the country. Already, changes in wiring practices dictated by better 

electrical codes and the required use of smoke alarms have 

made new construction safer.7

Residents demand higher levels of electrical energy to 

power their homes and appliances than they did in the past, 

and new homes are built to meet this demand for multiple 

televisions, phones, hairdryers, microwaves, washers and 

dryers, etc. As the consumers’ electrical demands increase, 

so does their expectation that their homes will supply 

adequate power to meet these. They meet their needs by 

adding more circuitry (and circuit breakers in blank spots 

on the breaker panel, or even another circuit breaker box) 

and outlets to accommodate their purchases. If an outlet 

is added to an existing circuit, then the load easily can be 

more than the wiring originally was designed to conduct—

perhaps decades ago.8

What these consumers really do is create unseen hazards in 

their homes. Inside the walls, wiring is heating and damaging its own insulation, wood frames are being charred by 

high-wattage light bulbs too close to ceilings, and fixture 

wattage ratings are being exceeded. But as long as the lights 

come on and the appliances start, the consumer remains 

unaware of the danger—until a fire starts.9

Where Residential Building Electrical 

Fires Occur

The functional and structural areas of the home are the 

most likely to experience electrical fires (Figure 1). Included 

in the functional category are bedrooms, dining rooms, 

kitchens, bathrooms, laundry areas, and the like. Fifteen 

percent of residential building electrical fires start in a 

bedroom (Table 2). The bedroom also is the leading area of 

fire origin for fires with injuries and dollar loss—bedrooms 

account for 30% of residential building electrical fires that 

result in injuries and 16% of residential building electrical 

fires that result in dollar loss. Structural areas of the home 

include areas such as crawl spaces, attics, walls, porches, and 

roofs. Attics, the second leading area of fire origin, account 

for 11% of residential building electrical fires. Over a quarter of all residential electrical fires start in these two areas. 

While fewer residential electrical fires start in lounge areas 

(family rooms, living rooms, and the like), these fires result 

in nearly a third of the deaths (31%). 
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 3

continued on next page

Figure 1. General Area of Fire Origin in Residential Building Electrical Fires, 2003–2005.

1.7

1.3

0.3

35.5

4.2

2.0

7.7

0.1

38.0

6.9

2.4

0.0% 5.0% 10.0% 15.0% 20.0% 25.0% 30.0% 35.0% 40.0%

Other area

Outside area

Vehicle area

Structural area

Equipment or service area

Service facilities

Storage area

Technical processing areas

Function areas

Assembly or sales area

Egress/Exit

Percent of Fires

Source: NFIRS 5.0

Note: Percentages may not equal 100 due to rounding.

Table 2. Leading Area of Fire Origin in 

Residential Building Electrical Fires, 

2003–2005 (fire-based).

Area of Fire Origin Fires

Fires with...

Deaths Injuries Dollar 

Loss

Bedroom for fewer 

than 5 people 15.1% 16.6% 29.6% 16.0%

Attic: vacant, crawl 

space above top 

story

11.3% — — 11.6%

Cooking area, 

kitchen 9.4% 6.4% 6.2% 9.0%

Wall assembly, concealed wall space 8.4% 5.7% 5.9% 8.2%

Common room, den, 

family room, living 

room, lounge

6.8% 31.2% 13.9% 7.1%

Function areas, 

other — 8.3% 6.6% —

Source: NFIRS 5.0

What Ignites

By far, building structural components is the largest category of items first ignited in residential building electrical 

fires (Figure 2). Structural components include structural 

member or framing, insulation, trim, wall coverings, flooring, and the like. Of these components, structural framing 

(usually wood) accounts for 17% of residential electrical 

fires (Table 3). Insulation and interior and exterior wall 

coverings (e.g., paneling, wallpaper, siding) account for an 

additional 18% of residential electrical fires. However, the 

leading item first ignited in residential electrical fires is the 

insulation around electrical wires and cables. At 30% of 

residential electrical fires, it accounts for nearly the entire 

general materials category. 

Together, insulation around electrical wires and structural 

member/framing account for 38% of all deaths from fires 

in residential buildings.
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 4

continued on page 8

Figure 2. General Items First Ignited in Residential Building Electrical Fires, 2003–2005.

4.1

1.0

44.7

7.9

7.0

0.6

0.8

1.4

0.9

31.6

0.0% 10.0% 20.0% 30.0% 40.0% 50.0%

Other

Multiple items

Structural component or finish

Furniture, utensils

Soft goods, wearing apparel

Adornment, recreational material, signs

Storage supplies

Liquids, piping, filters

Organic materials

General materials

Percent of Fires Source: NFIRS 5.0

Note: Percentages may not equal 100 due to rounding.

Table 3. Leading Items First Ignited, 

Electrical Fires, 2003–2005.

Item First Ignited Percent of 

Fires

Electrical wire, cable insulation 30.2%

Structural member or framing 17.1%

Thermal, acoustical insulation within wall, partition, 

or floor/ceiling space 7.0%

Interior wall covering excluding drapes, etc. 6.5%

Exterior sidewall covering, surface, finish 4.7%

Source: NFIRS 5.0

When Residential Building Electrical 

Fires Occur

Heating, lighting, and cooking activities are highest in 

winter and so, too, are the occurrence of indoor fires stemming from electrical problems. Throughout most of the 

year, the pattern of residential electrical fires is consistent, 

but occurrences peak in December and January, accounting 

for 22% of all such fires (Figure 3). In the winter months, 

the relative humidity within the walls of a typical home 

can be very, very low and can turn wood wall framing into 

kindling, easily ignited by an arcing current. Fire deaths 

also are high in these months, but March and October, still 

dry months, both have similar peaks. Summertime has the 

lowest incidence of deaths resulting from electrical fires in 

the home. Figure 4 shows that late afternoon and evening 

are the most likely time for electrical fires to occur in residences. But it is the hours before dawn, between 3 and 6 in 

the morning, when deaths are most frequent.

Equipment Involved in Residential Building 

Electrical Fires

Wiring and electrical components have a life expectancy 

that does not always equal the life cycle of the building. As 

the electrical equipment wear out, fires are more probable. 

Electrical wiring with its various components is by far the 

major culprit in residential building electrical fires. Lamps 

and other lighting and cords and plugs also present severe 

problems (Figure 5). 

Fire Spread

Most residential building fires are confined to the object 

of origin (62%) with 38% of fires spreading through the 

residence and beyond (Figure 6). Fire spread from residential building electrical fires, however, has nearly the opposite 
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 5

Figure 3. Month of Occurrence for Residential Building Electrical Fires and Fire Deaths, 

2003–2005.

10.5

8.0 8.1

7.1 7.3 7.5

8.6

7.9

7.1

7.8

8.6

11.5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent of Fires

13.0

9.3

12.5

8.8 8.8

4.2 4.2

3.2

5.1

11.1

8.3

11.6

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent of Fire Deaths Source: NFIRS 5.0

Note: Percentages may not equal 100 due to rounding.
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 6

Figure 4. Alarm Time for Residential Building Electrical Fires and Fire Deaths,

2003–2005.

3.6

3.3

2.9

2.6 2.6 2.5

2.9

3.4

3.6

4.0

4.5 4.6 4.5

4.9 4.8

5.0

5.2 5.2

5.5 5.6

5.3

5.0

4.7

3.8

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Mid-1A

M

1A

M-2A

M

2A

M-3A

M

3A

M-4A

M

4A

M-5A

M

5A

M-6A

M

6A

M-7A

M

7A

M-8A

M

8A

M-9A

M

9A

M-10A

M

10A

M-11A

M

11A

M-12PM

12PM-1PM

1PM-2PM

2PM-3PM

3PM-4PM

4PM-5PM

5PM-6PM

6PM-7PM

7PM-8PM

8PM-9PM

9PM-10PM

10PM-11PM

11PM-Mid

Percent of Fires

10.6

6.0

4.2

8.8

7.9

11.1

3.7

3.2

5.6

2.8 2.8

1.9

0.5

2.8

1.4

2.3

1.4

0.0

3.2

2.8

1.4

4.6

2.8

8.3

0.0

2.0

4.0

6.0

8.0

10.0

12.0

Mid-1A

M

1A

M-2A

M

2A

M-3A

M

3A

M-4A

M

4A

M-5A

M

5A

M-6A

M

6A

M-7A

M

7A

M-8A

M

8A

M-9A

M

9A

M-10A

M

10A

M-11A

M

11A

M-12PM

12PM-1PM

1PM-2PM

2PM-3PM

3PM-4PM

4PM-5PM

5PM-6PM

6PM-7PM

7PM-8PM

8PM-9PM

9PM-10PM

10PM-11PM

11PM-Mid

Percent of Fire Deaths Source: NFIRS 5.0

Note: Percentages may not equal 100 due to rounding.
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 7

Figure 5. General Equipment Involved in Ignition in Residential Building Electrical Fires, 

2003–2005.

1.7

9.9

3.7

46.8

3.1

23.5

11.3

0.0% 10.0% 20.0% 30.0% 40.0% 50.0%

Other equipment

Heating-related 

Electrical distribution,

power transfer

Electrical wiring

Power transfer

Lamp, lighting

Cord, plug

Percent of Fires

Source: NFIRS 5.0

Figure 6. Fire Spread in Residential Building Electrical Fires, 2003–2005.

2.4

14.6

4.3

16.6

62.1

2.3

23.4

8.8

30.9

34.6

0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0%

Beyond building of origin

Confined to building of origin

Confined to floor of origin

Confined to room of origin

Confined to object of origin

Percent of Fires

Residential Building Electrical Fires

All Residential Building Fires

Source: NFIRS 5.0
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 8

profile—these electrical fires are more likely to spread 

throughout the home. Sixty-five percent of residential 

building electrical fires spread beyond the initial object that 

started the fire. Structural members and framing contribute 

most to flame spread (27%).

Leading Factors Contributing to 

Residential Building Electrical Fires

Not surprisingly, when a factor was noted as contributing to 

ignition, some type of electrical failure accounted for 89% 

of electrical fires in residential buildings. The four leading 

specific factors, all electrical issues, account for 81% of these 

electrical failures (Table 4).

Table 4. Leading Factors Contributing to 

Ignition, Electrical Fires, 2003–2005.

Factor Contributing to Ignition Percent of 

Fires

Electrical failure, malfunction, other 35.4%

Unspecified short-circuit arc 26.0%

Short-circuit arc from defective, worn insulation 15.1%

Arc from faulty contact, broken conductor 4.4%

Mechanical failure, malfunction, other 3.8%

Source: NFIRS 5.0

Electrical Safety Devices

Arc Fault Circuit Interrupters (AFCI) or Arc Fault 

Interrupters (AFI) and Ground Fault Circuit Interrupters 

(GFCI) or Ground Fault Interrupters (GFI) perform different jobs.10 A GFCI protects you from electrical shock. 

An AFCI breaker protects you and your house from a fire 

caused by electrical arcs. 11,12

GFCIs traditionally meet the standard for protecting against 

electric shock. GFCIs were first implemented as an electrical 

code requirement in the early 1970s for bathroom outlets. 

Over time, GFCIs have become required in other areas likely 

to pose a risk for shock, especially those in potentially wet 

locations such as kitchens, unfinished basements, garages, 

outdoors, Jacuzzis, and hot tubs. Although GFCIs are 

designed to protect people from electrocution, they are not 

designed to protect against house fires. 

AFCIs identify arcing at cords, outlets, and lights and trip 

breakers before the arcing can start a fire. AFCIs recently 

became a requirement for bedrooms in new construction 

by the NEC in use in many local and State jurisdictions. This 

technology is better suited for new homes with updated 

wiring rather than older homes where the grounding for 

wiring is questionable.

Examples

The following recent examples illustrate typical residential 

building electrical fire scenarios:

July 2007, Havre, MT: A family lost all of their personal 

belongings in an electrical fire. The fire, which officials 

said originated in one of the wall outlets, consumed an 

8' x 14' bedroom and its contents. Fire or smoke was 

not seen although a family member smelled something 

burning. Bedrooms were checked and, in the corner of 

one, was a fire. “At first it started small but it went up 

fast,” the young woman observed.13

November 2007, Newton, KS: A malfunction in the 

electric distribution system was determined to be the 

cause of an apartment complex fire that sent three 

people to the hospital. The fire originated in an electric 

box on the outside of the building near the stairwell.14

December 2007, Salem, OR: Fire blamed on a worn 

extension cord extensively damaged a house in Salem, 

OR. Fire investigators noted the fire was caused by an 

extension cord that had been pinched under the corner 

of a couch. The investigators expected the house to be a 

total loss.15

Conclusion

While the source of an electrical fire can be hard to determine, some known culprits—overloading circuits with heat 

producing equipment, for example—can lead to items such 

as the insulation around electrical wires and cables catching fire, either slowly or immediately. With over three times 

more residential building electrical fires than nonresidential building electrical fires, it is important to ensure that 

the electrical panels, outlets, switches, and junction boxes 

in your home are correctly installed and not damaged or 

modified by unlicensed electricians. Do not use extension 

cords and multiple plug-in devices as a replacement for new 

circuits. Since 15% of residential building electrical fires 

start in a bedroom, upgrade bedrooms with AFIs where 

possible. 

Never use water on suspected electrical fires, and inform 

your local fire department when you call 9-1-1 that you 

presume the fire to be electrical.

Continued from page 4
TFRS Volume 8, Issue 2/ Residential Building Electrical Fires Page 9

Notes:

1NFIRS 5.0 contains both converted NFIRS 4.1 data and native 

NFIRS 5.0 data. This topical report includes only native 5.0 data 

and excludes incident type ‘110’, since it is a 4.1 conversion code.

2National estimates are based on 2003 to 2005 native version 5.0 

data from the National Fire Incident Reporting System (NFIRS) 

and residential structure fire loss estimates from the National Fire 

Protection Association’s (NFPA) annual survey of fire loss. Fires are 

rounded to the nearest 100, deaths to the nearest 5, injuries to the 

nearest 25, and loss to nearest $M.

3 In NFIRS 5.0, a structure is a constructed item of which a building is one type. The term “residential structure” commonly refers 

to buildings where people live. The definition of a residential 

structure fire has, therefore, changed to include only those fires 

where the NFIRS 5.0 structure type is 1 or 2 (enclosed building 

and fixed portable or mobile structure) with a residential property use. Such fires are referred to as “residential buildings” to 

distinguish these buildings from other structures on residential 

properties that may include fences, sheds, and other uninhabitable 

structures. In addition, incidents that have a residential property 

use, but do not have a structure type specified are presumed to be 

buildings.

4 “Drawing Wisdom from the Wall,” http://www.ul.com/newsroom/wiring/index.html

5 Ibid.

6

 Rasdall, Joyce, “Aging Residential Wiring Issues: Concerns for 

Fatalities, Personal Injuries, and Loss of Property,” Education 

Presentation, Annual Household Equipment Technical Conference, 

Louisville, KY, Oct. 26-28, 2005, http://www.esfi.org/educators/

documents/AheeAgingResidentialWiringIssues5-05.pdf 

7

 Ibid.

8

 Ibid.

9

 “Drawing Wisdom from the Wall,” http://www.ul.com/newsroom/wiring/index.html

10 AFCIs also are known as Arc Fault Interrupters (AFI). GFCIs also 

are known as Ground Fault Interrupters (GFI).

11 Consumer Product Safety Commission, GFCI Fact Sheet, http://

www.cpsc.gov/cpscpub/pubs/99.html 

12 Consumer Product Safety Commission, AFCI Fact Sheet, http://

www.cpsc.gov/CPSCPUB/PUBS/afcifac8.PDF

13 “Electrical fire consumes family belongings,” Elizabeth Doney, 

Havre Daily News, (Havre, MT), http://www.havredailynews.com/

articles/2007/08/07/local_headlines/local.txt

14 “Accident ruled cause of Nov. 18 blaze,” The Kansan.

com, http://www.thekansan.com/stories/112707/topstories_112707008.shtml

15 “Extension cord blamed for fire,” Statesman Journal (Salem, 

OR), http://www.statesmanjournal.com/apps/pbcs.dll/

article?AID=/20071213/NEWS/712130324