Solo dwellers’ housing issues have received little attention in housing studies. This article addresses their domestic spatial needs in the context of the Helsinki Metropolitan Area (HMA) where dwelling sizes have decreased rapidly. A critical stance towards the trend of constructing small one-room apartments and related norm deregulation is based on the notion that dwellings should be at least 50 m2 and contain more than one room in order to overcome the shortage of space experienced by solo dwellers (N = 1453). Emphasizing the perspective of housing design, the findings provide insights into floor plan design by focussing on apartment types and sizes in relation to kitchen types and the experienced shortage of space. All in all, the article demonstrates that solo dwellers’ domestic spatial needs are more diverse than expected based on their household size and related public discussion on urban housing.