The paper presents soft densification as a phenomenon suitable for the sustainable development of ageing suburban housing of larger cities in the Czech Republic. The background, potential, and risks are described using literature and foreign practical experience and suggest the possible application of this strategy in Czech conditions. A description of the spatial types of soft densification regarding the reserves of existing land and houses, and a description of the main actors of the phenomenon serve as a basis for further research. The article also includes an introduction of the online database of Dense Satellites, which was created to collect good practice projects and popularize the topic among the wider public.