Helsinki Metropolitan Area is a growing region with rising demand for housing. The low density of housing, which is very often visible in Finland and in other Nordic countries, bears great potential for infill development to conquer or at least ease the growing need for housing. Densification is often argued to be one answer to the environmental pressures the built environment is coping with. The main argument is that, densification of residential areas will make better use of existing infrastructure and decrease travelling. In addition to the positive environmental impacts, the infill developments are argued to have societal benefits such as diversification of population and land use, and increased vitality of the area. Infill development can also bring economic benefits to various parties. At the same time that the city is seeking savings in infrastructure construction and maintenance costs, housing companies may also receive financial means from the construction of a new building on their property. This income can potentially cover costs needed for example for energy and pipe renovations, and lift construction.

In Finland where the level of owner-occupancy in housing is high, home owners can be seen as key players when discussing new infill developments. While the public sector sets the frames, eventually much is in hands of the real estate owner and inhabitant. Even though the impact of infill developments has been studied thoroughly, little is still known about the willingness or unwillingness of inhabitants to support infill development in their neighborhood. The topic deserves more attention, as infill development projects often face opposition from the inhabitants, despite the many known benefits.

The aim of this study is to find connections between characteristics of areas and their inhabitants' attitude towards infill development. The results can give a better understanding of inhabitants' appreciations. This knowledge could be applied in urban planning processes to support infill developments in the future. The inhabitants' attitudes are examined using a questionnaire survey. The survey was carried out in the Helsinki Metropolitan Area, and the extensive questionnaire received opinions from 1088 respondents. The inhabitants' attitudes towards infill development are compared to different areal characteristics to reveal their interconnections and significance.