The efficiency strategy to exploit the potential for energy savings in buildings still is applied rather slowly in most countries. In addition, there are indications that energy savings are partly compensated particularly by wealth but also rebound effects, the "empty nest" (persistence of elderly people and couples in family homes), and cohort effects (e.g. vintages of people or buildings). In Germany, as in other European countries, the existing trend in housing is a continuously growing floor space per capita. Over the last decades it expanded from about 20 m2 in 1960 to currently 45 m2 per person. Forecasts expect a further increase to more than 50 m2 per person. Obviously, more floor space needs more energy for space heating and cooling, ventilation, and lighting, but it also allows the household to operate more and or bigger appliances, all of which increase energy consumption.
On the other hand, housing projects emerge offering relatively small private living spaces in combination with various shared spaces to use. Many of them are based on private initiatives. But what is the motivation behind it? And is there a higher need for new living concepts in the future?
The proposed paper presents main drivers of increasing floor space per capita in Germany and discusses the question if more space is necessary for higher comfort. It presents different examples of housing concepts that strive to achieve good living with less space and suggests a "building typology of sufficiency".
Finally, the paper discusses qualitatively to which extent these housing concepts can lead to less energy use and emissions. In this way sufficiency could be best friend with efficiency and tackle wealth, rebound, and other effects that counter-act efficiency progress. But therefore, as the paper concludes, politics and policies should recognise sufficiency as a field of action instead of referring to individual decisions and lifestyles.
Estimating the sufficiency potential in buildings : the space between underdimensioned and oversized
(2019)
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?