2.1.12	2005 Residential Delivered Energy Consumption Intensities, by Vintage
			Per Square				Per Household				Per Household				Percent of
Year Built			Foot (thousand Btu)			(1)	(million Btu)				Member (million Btu)				Total Consumption
Prior to 1950				74.5				114.9				46.8				24%
1950 to 1969				66.0				96.6				38.1				23%
1970 to 1979				59.4				83.4				33.5				15%
1980 to 1989				51.9				81.4				32.3				14%
1990 to 1999				48.2				94.4				33.7				16%
2000 to 2005				44.7				94.7				34.3				8%
Average				58.7				95.0				40.0
Note(s):	1) Energy consumption per square foot was calculated using estimates of average heated floor space per household. According to the 2005 Residential Energy Consumption Survey (RECS), the average heated floor space per household in the U.S. was 1,618 square feet. Average total floor space, which includes garages, attics and unfinished basements, equaled 2,309 square feet.