Within the last years, negative side-effects of increasing anthropogenic use of energy have been more and more recognised. Besides an enforced use of renewable energy sources and a more efficient use of energy, it will be necessary to reduce the level of energy consumption in industrialized societies in order to achieve a sustainable energy system. Although private households will play a crucial role in this transition, private energy consumption seems hard to tackle, as it results from highly complex patterns of decision making, life-styles, values, etc. After introductory chapters including a situation and problem analysis, the master thesis demonstrates the degree of energy conservation that can be reached by behavioural changes of private households - based on Austrian climate conditions. Model calculations are applied for households with different behavioural patterns in regard to room temperature settings, ventilation habits, hot water and electricity use. The results show the huge potential for energy savings through behavioural changes. The assumptions on an energy saving behaviour resulted in an energy demand of minus 32% in comparison to the average. Squandering behavioural patterns resulted in plus 74% compared to the average. The second part of the thesis starts with an introduction of the idea of participation and describes examples of participatory approaches in the context of private energy use. The idea of participatory approaches is then discussed along the theoretical framework of a socio-technical approach. Effects of participatory processes are shown, and limiting as well as promoting factors for a successful implementation are identified.The thesis concludes that participatory approaches allow people to try out new behavioural patterns under "laboratory" conditions. They can provide an additional incentive as well as the information and support that are necessary to enable people to change their energy behaviour towards sustainability. They cannot be the only solution to decrease energy demand of private households. But they should be part of a bigger strategy that includes other endeavours to lead the system towards sustainability, such as political and financial incentives or directives.