To assist users with describing the characteristics of their house, when users first enter the Home Energy Saver site, they are assigned default house characteristics based on the Census Division in which their ZIP code is located. These default characteristics were developed by analyzing the 1993 and 2005 Residential Energy Consumption Survey (RECS) microdata (US DOE 1995a, US DOE 2009). Consumption and characteristics are based on the RECS 2005 survey, supplemented by lighting and electrical cooking consumptions from RECS 1993. All analysis is based on a subset of 4,382 homes (2009 sample); mobile homes and single family homes (both attached and unattached). Where a house characteristic can only have discrete values (e.g., type of heating fuel or presence of dishwasher), we tabulated the saturation of that characteristic in the RECS data set and selected the most common value. For example, if natural gas was the most common heating fuel in a region, then the default house is assumed to use natural gas for heating. Characteristics based on climate zone contains the default input values for each census division. For the remaining characteristics for the house, a single value was applied across all divisions. National default characteristics contains these nation-wide default housing characteristics. Default house shell characteristics, for use in DOE-2, are described in the DOE-2 companion report (Warner 2005) which is included in Appendix E.
 Microdata are the household-level data from each of the houses in the RECS sample. http://www.eia.doe.gov/emeu/recs/recspubuse05/pubuse05.html