The transition towards sustainability requires changes in almost every aspect of our lives. The transport system is one of the areas where significant change still needs to happen. Sustainable mobility intends to reduce the need to travel, encourage greater use of public transport, walking, and cycling, improve transportation accessibility, and reduce travel distances. Studies of sustainable cities have determined a set of parameters that characterise a sustainable city. The contemporary 15-minute city concept advocates that residents will be able to enjoy a higher quality of life in which they can effectively fulfil the essential social functions of the city. In European cities, large housing estates (LHE) form a large part of the population accommodation, and in Eastern and Northern Europe, it is often even the majority. These mass housing districts were originally planned to provide residents with everything they need for everyday life within easy reach on foot. However, the location of these districts in the city, their insufficient provision of convenient and efficient public transport, the limited variety and quality of local infrastructure, the gradual loss of local facilities due to viability challenges, as well as the residents’ wide choice of options for ensuring their daily needs have created a situation where the original idea of LHEs is increasingly failing. Through selected case studies in five European cities, the aim is to understand whether the essential urban social functions of a ’15-minute city’ are present in the urban pattern of LHEs and whether the amount and proximity to these specific services would help in saving time wasted in traffic, thus promoting sustainable mobility.