Table 6b. U.S. Residential Energy Intensity Using Weather-Adjusted Site Energy¹ by Census Region and Type of Housing Unit, 1978-2005
(Million Btu per Household Member)

Type of Housing Unit and Census Region
	1978	1980	1981	1982	1984	1987	1990	1993	1997	2001	2005
U.S. Total	45	39	40	36	39	40	40	38	38	37	37
Mobile Home	33	32	32	27	30	31	31	30	31	30	29
Single-Family Detached	46	40	41	37	40	41	42	41	41	41	40
Single-Family Attached	44	37	38	37	42	41	39	36	40	39	36
Apartments in Buildings with 2 to 4 Units	51	42	44	39	39	41	45	39	40	36	35
Apartments in Buildings with 5 or More Units	36	38	36	37	35	35	28	25	23	21	27
Total Northeast	54	46	47	43	47	49	50	45	47	46	47
Mobile Home	53	34	32	34	42	37	32	40	44	42	45
Single-Family Detached	56	44	45	42	47	51	54	51	51	53	52
Single-Family Attached	44	40	45	45	48	47	44	38	50	46	39
Apartments in Buildings with 2 to 4 Units	59	53	51	43	48	49	54	47	48	48	46
Apartments in Buildings with 5 or More Units	48	54	51	48	44	43	35	31	31	26	36
Total Midwest	56	47	55	43	50	51	52	51	51	48	46
Mobile Home	48	48	52	33	39	40	40	39	48	43	43
Single-Family Detached	57	48	57	44	51	52	54	53	53	52	48
Single-Family Attached	59	37	50	33	51	48	48	57	54	47	48
Apartments in Buildings with 2 to 4 Units	56	43	56	44	49	57	65	57	51	45	52
Apartments in Buildings with 5 or More Units	43	39	36	39	49	50	38	36	31	28	32
Total South	32	33	31	32	31	32	33	33	32	33	32
Mobile Home	25	27	24	22	21	24	22	23	26	24	26
Single-Family Detached	35	34	33	33	33	35	37	36	36	37	34
Single-Family Attached	29	38	28	36	32	29	28	33	30	36	30
Apartments in Buildings with 2 to 4 Units	29	30	29	36	30	26	27	22	26	24	25
Apartments in Buildings with 5 or More Units	19	28	27	30	26	27	23	23	20	21	23
Total West	40	31	31	29	31	30	29	27	27	26	29
Mobile Home	33	33	38	32	35	34	34	30	28	31	27
Single-Family Detached	41	32	33	30	34	31	30	30	30	30	32
Single-Family Attached	43	28	30	25	28	36	40	25	26	23	29
Apartments in Buildings with 2 to 4 Units	49	29	25	27	23	25	27	23	23	18	19
Apartments in Buildings with 5 or More Units	35	26	24	27	26	25	20	16	16	15	17
1.The Btu value of energy at the point it enters the home, building, or establishment, sometimes referred to as "delivered" energy. Sources: Energy Information Administration, Residential Energy Consumption Surveys, 1978, 1980, 1981, 1982, 1984, 1987, 1990, 1993, 1997, 2001 and 2005; National Oceanic and Atmospheric Administration tapes.