Climate change is and will have a severe impact on urban areas. Dutch cities are actively searching ways for successful climate adaptation. One way to do this is by experimenting with sustainable innovations in urban living labs (ULLs). This is a place where different urban actors, such as governments, businesses, knowledge institutes and citizens, collectively experiment with innovative ways to solve urban problems in a sustainable matter. This collective experimenting is also known as co-creation. From the beginning of the COVID-19 measures in 2020, ULLs are facing difficulties regarding co-creation as a result of the measures that are taken for social distancing. Furthermore, these social distancing measures affect the social cohesion in communities, and therefore most likely also in ULLs. The relationship between social cohesion and ULLs has not yet been studied extensively, and the COVID-19 measures give an opportunity to understand ULLs in a new way. Therefore, this thesis aims to answer the following research question: What is the relationship between social cohesion and urban living labs in times of COVID-19? The research methodology consists of expert interviews and a single case study research in ULL Reyeroord+ in the neighbourhood Reyeroord in Rotterdam. The expert interviews are conducted with five experts that are active in five different ULLs in the Netherlands. The case study research consists of document analysis to understand the aim and activities of ULL Reyeroord+, as well as interviews with citizens of Reyeroord. The research data is analysed using a social cohesion framework that subdivides social cohesion into the quality of social relations, identification with the social entity, and orientation towards the common good. Overall, the experts believe that regular physical contact, a long-term relationship, having an equal mindset, involving citizens in decision-making and experimenting, and taking a qualitative approach are perceived as being the most important for a successful ULL. From the citizen interviews became clear that problems of violence, waste and parking are experienced as priority problems in the neighbourhood and that they are, together with the experienced deterioration of the social situation, seen as ‘pauperisation’ or ‘degradation’. It appears that most citizens have other priorities than climate adaptation, for example in terms of income. This could impact the social cohesion, as it can affect people’s willingness to take part in civic engagement and social networking. The communication between actors in Reyeroord+ were impacted by the COVID-19 measures, as meetings were organised online. Furthermore, the COVID-19 measures have impacted citizens’ involvement in the neighbourhood, mainly by increasing the awareness of people’s surroundings. This has most likely affected the community attachment of citizens. It is possible that this increased awareness will have a positive impact in the future. Furthermore, social cohesion and ULL Reyeroord+ are connected through the development of a new way of communicating that deviates from the current top-down approach, and through the development of a sense of ownership among citizens. ULL experiments are therefore not only sustainability experiments, but also an opportunity for actors to learn how to approach citizen engagement and to develop a new way of communicating with citizens that could ultimately be beneficial for climate adaptation in urban areas. The results are debated on the basis of several discussion questions. The main limitations for this research lie with the research methods, which are not as ethnographic as was anticipated due to the COVID-19 restrictions, and the social cohesion framework, which is susceptible for subjectivity. The scientific contribution is the social science approach in the field of ULLs, which builds on existing literature. Implications and recommendations are given for the municipality and the citizens as actor groups. Finally, it is suggested that further research on citizens’ role in co-creation processes would be valuable for future research.