This article explores how the architecture of neighbourhoods influences interethnic tensions in ethnically diverse neighbourhoods. We found that people of Dutch descent living in apartments in four storey walk-ups in ethnically diverse innercity neighbourhoods seem less likely to feel threatened by ethnic diversity than people living in in similarly diverse suburbs characterized by larger housing blocks featuring inner courtyards and galleries. Further analysis reveals that the residents of these suburbs share various types of semi-public spaces and have competing interests in using them, whereas the residents of inner-city neighbourhoods share fewer semi-public spaces and therefore have more scope to choose when and how to engage in interethnic contact with other residents. We also explore residents’ housing histories and examine differences between people who either have more negative or more positive views on diversity with regard to their active participation in various organizations. This last piece of the puzzle will be used to analyse the potential for both negative and positive messages about ethnic diversity to spread. Based on the empirical findings, we will formulate some building blocks that can help to further explain the level of perceived ethnic tensions in ethnically diverse neighbourhoods.