Estimating the sufficiency potential in buildings : the space between underdimensioned and oversized

The emission reduction potential of energy efficiency and energy supply in buildings is estimated in various energy and climate action plans, scenarios, and potential analyses. But the third pillar of sustainability - sufficiency - is neglected in most studies.The increasing demand of space per person in the residential sector is a trend in most European countries. Its implication on energy use, demand for resources like land, building material, equipment, and waste production is enormous. Next to the ecological impact, the distribution of space has social and societal effects. Thus, sufficiency policies in the building sector complementing efficiency and energy policy are needed for a sustainable development of the European building stock. But how can a sufficiency potential in the building sector be estimated? How much space and equipment is needed for a decent living and how much is too much? The paper proposes four areas of sufficiency in buildings: space, design and construction, equipment, and use. It presents a set of indicators, a quantitative estimate of energy savings from reduced per capita floor area, and visualises the sufficiency potential in European countries in an experimental approach. The final discussion focuses on the question: What does this mean for policy making