Background: Previous research identifies organisational culture as one of a number of factors associated with the quality of life outcomes of group home residents' with intellectual and developmental disabilities. This study aims to elaborate on the dimensions of group home culture in settings in England. Method: Participant observations and semi-structured interviews with staff were carried out in two group homes. Field-notes, interview notes and transcripts were analysed using inductive thematic analysis by a researcher naïve to the project and the previous literature. Initial coding was re-examined after sensitisation to theorised models in previous literature to identify the most parsimonious fit. The two settings were rated and compared using a five-point Likert scale for each of the dimensions. Results: The findings describe group home culture across seven dimensions. There were mixed ratings across the different dimensions reflecting inconsistencies in culture that were reflected in staff practice. The challenge in assigning a global rating of culture in group homes, which includes interactions across multiple staff and multiple residents over time, was highlighted. Conclusion: The development of an observational measure of culture is highlighted as potentially helpful in understanding and responding to culture in services for individuals with intellectual and developmental disabilities.