Washing laundry is one of the most widespread housework in the world. Today, washing machines do this work in many private households, using water, electricity, chemical substances, and process time. Although energy efficiency is in the focus of many regulations which have already achieved significant improvements, the question remains, how relevant these processes are in terms of the absolute impact on resources and whether there are possibilities to improve even further by looking abroad. This survey, which is based on published data, compares the energy and water consumption for automatic laundry washing in an average private household with the total energy and water consumption of private households. Only little data are available on resource consumption for laundry washing and reliable figures based on in-use measurements are hard to obtain. But although some of the data in this report are poor, this is the first work that tries to elucidate the contribution of automatic laundry washing to the total electricity and water consumption of households in selected countries worldwide. The report estimates the resource consumption of roughly 590,000,000 washing machines in 38 countries with about 2.3 billion people, which is about one third of the world population. The results of this work show that laundry washing in private households is done with quite different amounts of electricity and water in different parts of the world both in absolute and relative comparison to the overall household consumption. But due to different consumer habits in dealing with the achieved washing performance in the different global regions, the best practice in washing laundry in a most sustainable way cannot be determined yet. Further research is needed to form a basis for a most sustainable development of resource consumption in private households.

The study demonstrates that it is possible to compensate for the loss of hygiene effectiveness of laundering at lower temperatures using detergents with activated oxygen bleach or by extending the wash cycle time.

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Sustainability is a guiding principle for a responsible, future‐oriented 21st century lifestyle and this already begins in private households with the daily household tasks. Approximately 25% of an average household's electricity consumption is required to do the laundry and dishwashing – 5% alone is for washing clothes with a corresponding energy consumption of 6 billion kilowatt hours. In addition, 600 000 tonnes of detergent and 330 million cubic metres of water are used for textile care in Germany. These figures provide the rationale for the scientific study of current practices of using washing machines and for a resulting estimate of the latent energy‐saving potential in German households. In the context of the in‐home study presented here, 236 private households throughout Germany were studied with respect to their washing practices and existing knowledge about topics on the sustainable, energy‐saving use of their washing machines. Overall, across all households 2867 wash cycles were individually recorded and subsequently analysed over a 4‐week period. The results of this study show that washing machines tend to be underloaded, and therefore maximum loading of the machines could lead to a reduction of wash cycles per household. With respect to detergent dosage, it was determined that the consumer does not adjust the dosage to the textile type, load size, soil level and/or water hardness, and this can lead to under‐ or overdosing depending on prevailing conditions. Finally, the selection of the wash temperature showed a 90°C/95°C programme was only chosen in 2.3% of all recorded wash cycles, however, every fourth cycle was completed at 60°C. Therefore, adjusting the load size and detergent dosage as well as selecting the right wash temperature are key themes to be taken into account in future consumer communication about energy‐saving households.

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