With one quarter of final energy consumption, the German household sector is in the focus of policies to implement the Energiewende towards a low carbon society. Residential buildings need to be decarbonised entailing that domestic household energy consumption requires substantial changes. Policy interventions are attempting to foster the implementation of energy efficiency measures (insulation of the building envelop i.e. façade, roof etc.; replacement of windows with insulation glazing) and the installation of sustainable generation technologies (e.g. solar thermal heating, heat pumps, photovoltaic systems). However, private households do not seem to sufficiently respond to current policy instruments. Against the backdrop of mediocre effectiveness of present instruments and the impending breach of climate protection agreements, this thesis contributes to an improved understanding of energy-related household decisions and establishes a framework to describe and analyse these decisions. Results imply that economic and financial aspects are relevant, but not sufficient to explain energy-related household decisions. The decision-making clearly deviates from financial investment calculus and for an improved understanding the conceptualization as environment-related strategic consumer decisions is helpful. Besides economic considerations, household decisions are determined by comfort aspects, settlement structure and spatial dependence.