This dataset was generated to analyse essays and interviews related to the empirical analysis of five pilots addressing urban sustainability challenges. In all pilots, the interaction between Galleries, Libraries, Archives, and Museums (GLAMs) and Citizen Science (CS) practices was a core component. In Delft, children’s perceptions of urban spaces were collected and discussed through a collaboration between a university and a public library. In Tallinn, a community museum supported the testing of a digital visualisation tool to enhance citizens’ feedback in urban planning. In Vienna, an urban research institute and an academic library co-designed two pilots addressing urban heat and the transformation of public spaces. Members of the pilot teams were asked to compose an essay for each city, following the same template. To further learn about the role of GLAMs in CS initiatives, six members of the pilot teams and a public library director were interviewed following a structured interview protocol. The interview questions were derived from the key insights identified in the essays and related literature. Inductive coding was used to derive concepts and ideas from the data (essays and interviews). We used a ground-up approach where the codes were derived from the data without preconceived notions, refined through iterations, and grouped into five thematic families. This dataset provide all quotes and codifications (55 codes tagged in a total of 10 documents).