Urban regeneration with a view to efficient use of urban areas has been a strategy for urban development for decades. Densification is used as a planning approach to promote the implementation of the compact city model and to discourage urban sprawl. The central parts of the city are usually of high density, so the areas outside the city’s historic centre are seen as potential sites for urban densification. In many European cities large-scale residential areas built after the Second World War occupy a significant part of the territory outside of the city’s historic centres. Today, these housing areas are in most cases sleeping areas with great potential for development. Densification of urban areas outside of urban nuclei is not an easy task, and deals with a whole series of challenges. The paper examines the existing approaches focused on densification in large housing estates. In order to define the typical challenges of this process, the examples of infill developments in large housing area Imanta in Riga are analysed. The analysis of infill development in Imanta showed four possible approaches. Some approaches contribute to the improvement of public space for neighbourhood inhabitants in general, still some approaches tend to isolate the new development and inhabitants from the surrounding territory.