This paper analyzes the energy consumption during the period 2001-2006 of 192 flats distributed in three-storey buildings, in order to understand how current policies related to energy use could be improved for increased residential energy efficiency in Argentina. The buildings (1, 2 and 3 bedrooms) are located in La Pampa, central Argentina, in a moderate cold climate. The dimensional and energy-consumption variables are studied (area, envelope's area, FAEP = envelope's area/floor area; envelope's thermal resistance R, volumetric heat loss G and auxiliary heating Q(aux)). The natural gas consumption is analyzed at annual and seasonal levels. Consumption variability among buildings, storeys and flats is calculated. The quantitative analysis is coupled to a qualitative description through direct observation of the buildings. The results show: (a) a high incidence of natural gas consumption in the total annual energy consumption (natural gas+electricity), (b) seasonality of natural gas consumption, with a maximum value in the cold period July-August (variability = 80%). (c) little variability among buildings of the annual natural gas consumption (4.17%), (d) the lowest average energy consumption at the first floor, (e) high variability among flats on each storey, (0 winter consumption of a multi-family dwelling lower than a single-family dwelling of similar area and (g) little seasonal variability of the electricity consumption. (C) 2009 Elsevier Ltd. All rights reserved.