This thesis investigates the development of the long-term energy consumption in the Swedish households by estimating the sector’s total energy use and moreover, by examining how structural, institutional and economic factors have affected the demand for energy in the residential sector during the period 1913-2008. The investigated period covers a transition from traditional fuels, such as firewood, to fossil fuels and finally renewable energy. Previous quantitative research in the field of energy history has mainly focused on estimates of the primary energy supply, and further, this research has primarily been supply-oriented and has therefore focused the production of energy and the supporting infrastructure.   Overall, there is currently a lack of knowledge covering the long-term patterns in Swedish household’s energy consumption, including changes of the household energy mix. Identifying the central mechanisms behind these changes is the central research question in this thesis. Improved understanding of the energy transformation in Swedish households constitutes important knowledge for all actors who address energy and climate policy, not the least are knowledge about the complex factors that have affected the household consumption of fossil fuels, and thereby the household’s carbon dioxide emissions, important.- The aim of this thesis is to contribute to a better under-standing of the households' role in the energy system and how this role has changed during the 1900s until 2008.   The thesis uses a structural analytical approach, based on the concepts suggested by foremost Olle Krantz and Lennart Schön, to understand how the household’s energy consumption is linked to structural changes and techno-logical development. Although the structural analytical chronology, as suggested by Schön, primary builds on the industrial sector, the households can be expected to follow a similar pattern of transformation. This since general-purpose energy technologies is central for the pattern of transformation. However, since different sectors face different conditions and different abilities to utilize the energy, it is equally plausible to assume that the households follow a different pattern than other sectors. The response could either have been faster or slower.   The thesis concludes that the period covering the years 1913 to 1973 was a catching-up phase. The households lagged behind the industrial sector with respect to the transition to coal, electricity and oil. But in 1973 the households had however a similar energy mix to other sectors. The second conclusion is therefore that the households made a faster transition from oil to electricity and district heating. After 1985 the household’s energy mix took a different path compared to other sectors, which is the third conclusion. After 1985 the household’s oil consumption continued to decline as the consumption of district heating was increasing. The households were also more prone to increase their consumption of bio-fuels during the 1990s.