The Poznań Conurbation is a place where the suburbanisation process is appearing. The spatial transformation of suburban areas indicates that the application of research-based solutions, which in theory are supposed to reduce unfavourable trends, in practice appears to be a complicated task. Problems that remain unresolved for many years, as well as mistakes that often cancel efforts to solve these problems, are the obvious confirmation of that thesis. An important factor, which affects the poor spatial situation in suburban areas, is the lack of central urban planning indices. Although each municipality that is part of the Poznań Conurbation has its own up-to-date statutory land use policy study and other documents defining the local spatial planning policy, their records frequently contain solutions that are not beneficial to the public interest or sustainable development. Problems that are mentioned in producing them, as well as the unachieved aspirations and needs of space users, contribute to increased criticism of complex urban structures, while the strong position of developers in suburban areas raises the question as to whether the area of land dedicated to new buildings, especially residential ones is not too excessive when compared with current needs. This paper presents the results of research that concerns the relationship between the depopulation of Poznań and the increase of the built-up area in the neighbouring village of Skórzewo, which is a place of massive development of residential buildings and rapidly developing enterprises. The aim of this research is to introduce a tool for a more precise prediction of future spatial development in suburban areas.