The Chinese government encourages the promotion of community-based older people centres as a way to use space rationally, improve social inclusion and support older residents’ everyday lives. This exploratory study is the first to examine in depth the contradictory and consistent attitudes and suggestions of residents of different age groups for the design of an inclusive community-based centre for older and younger people in China. An integrative mixed-methods approach was used. In the quantitative phase, 270 older adults (⩾60 years) and 250 younger adults (<60 years) from Harbin were asked to complete questionnaires (older adults’ response rate = 87.0%; younger adults’ response rate = 87.2%). In the qualitative phase, seven focus group discussions (four groups of older adults, three groups of younger adults) were conducted. The findings indicate that older adults have a higher acceptance level of inclusive design and prefer to share spaces to improve intergenerational interactions than younger adults. Residents of all ages are more likely to share functional spaces related to health services, living services and physical exercise. Moreover, the study reveals some design suggestions: the location of the centre should be away from the residential area and integrated into a public community building; comprehensive services should be provided to older people and be accessible to the whole family; design should be barrier-free, and the climate and nearby spaces should be considered.