Million U.S. Housing Units

Total......................................................................... 111.1 10.9 26.1 27.3 24.0 22.8

Indoor Lights Turned On During Summer

Number of Lights Turned On

Between 1 and 4 Hours per Day......................... 91.8 8.2 22.3 23.1 19.7 18.4

1........................................................................ 28.6 2.3 7.1 6.7 6.4 6.2

2........................................................................ 29.5 2.6 6.9 7.7 6.6 5.7

3........................................................................ 14.7 1.3 4.1 3.4 2.9 3.0

4........................................................................ 9.3 1.0 2.4 2.2 2.1 1.8

5 or More........................................................... 9.7 1.0 1.9 3.2 1.8 1.8

Energy-Efficient Bulbs Used........................... 31.1 2.5 7.1 7.0 8.1 6.4

1.................................................................... 14.6 1.1 3.2 3.3 3.8 3.3

2.................................................................... 9.6 0.8 2.2 2.3 2.7 1.7

3.................................................................... 3.2 0.2 0.9 0.6 0.8 0.6

4.................................................................... 2.2 0.2 0.6 0.4 0.6 0.4

5 or More....................................................... 1.4 Q 0.3 0.4 Q 0.3

Number of Lights Turned On

Between 4 and 12 Hours per Day....................... 73.2 6.5 17.7 19.2 15.5 14.3

1........................................................................ 23.0 1.9 5.6 5.9 4.8 4.7

2........................................................................ 24.9 2.3 6.1 6.5 4.9 5.0

3........................................................................ 12.5 1.0 3.2 3.4 2.9 2.1

4........................................................................ 6.4 0.8 1.3 1.7 1.3 1.2

5 or More........................................................... 6.4 0.5 1.5 1.6 1.6 1.3

Energy-Efficient Bulbs Used........................... 27.9 2.4 6.8 6.1 7.3 5.4

1.................................................................... 13.6 1.1 3.1 2.8 3.8 2.8

2.................................................................... 8.9 0.9 2.5 2.1 1.9 1.5

3.................................................................... 3.0 0.2 0.7 0.6 1.0 0.5

4.................................................................... 1.3 Q 0.4 Q 0.3 0.3

5 or More....................................................... 1.1 Q Q 0.3 0.3 Q

Number of Lights Turned On

More than 12 Hours per Day............................... 27.0 1.6 6.2 6.9 6.1 6.2

1........................................................................ 14.8 0.8 3.3 3.6 3.6 3.4

2........................................................................ 7.8 0.5 1.7 2.2 1.5 1.8

3........................................................................ 2.0 Q 0.5 0.5 0.5 0.4

4........................................................................ 1.0 Q 0.3 0.3 0.2 Q

5 or More........................................................... 1.4 Q 0.3 0.4 0.3 0.2

Energy-Efficient Bulbs Used........................... 11.0 0.7 2.4 2.3 3.0 2.6

1.................................................................... 7.0 0.5 1.4 1.4 2.1 1.6

2.................................................................... 2.9 Q 0.7 0.7 0.7 0.7

3.................................................................... 0.5 Q Q Q Q Q

4.................................................................... 0.3 N Q Q Q Q

5 or More....................................................... 0.3 Q Q Q Q Q

Less than 

4,000 HDD

Housing 

Units 

(millions)

Climate Zone1

Table HC9.13 Lighting Usage Indicators by Climate Zone, 2005

Lighting Usage Indicators

2,000 CDD 

or More

and Less 

than 4,000 

HDD

Less than 2,000 CDD and --

Greater than 

7,000 HDD

5,500 to 

7,000 HDD

4,000 to 

5,499 HDD

Energy Information Administration

2005 Residential Consumption Survey: Preliminary Housing Characteristics Tables
 Million U.S. Housing Units

Less than 

4,000 HDD

Housing 

Units 

(millions)

Climate Zone1

Table HC9.13 Lighting Usage Indicators by Climate Zone, 2005

Lighting Usage Indicators

2,000 CDD 

or More

and Less 

than 4,000 

HDD

Less than 2,000 CDD and --

Greater than 

7,000 HDD

5,500 to 

7,000 HDD

4,000 to 

5,499 HDD

Outdoor Lights on All Night................................... 25.8 2.1 5.5 6.6 5.3 6.2

1............................................................................ 16.8 1.4 3.6 4.2 3.6 3.9

2............................................................................ 5.6 0.4 1.1 1.7 0.9 1.5

3 or More.............................................................. 3.4 0.3 0.8 0.8 0.7 0.8

Gas Outdoor Lights on All Night........................ 1.3 Q 0.3 0.3 Q 0.4

1........................................................................ 0.6 Q Q Q Q Q

2........................................................................ 0.7 Q Q Q Q Q

 1. One of five climatically distinct areas, determined according to the 30-year average (1971-2000) of the annual heating and cooling 

degree-days. A household is assigned to a climate zone according to the 30-year average annual degree-days for an appropriate nearby 

weather station.

 Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were 

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Consumption Survey: Preliminary Housing Characteristics Tables