This graduation project is part of the band published by the atelier 'Berlin as model'. The atelier reopens the discussion on the relationship between dwelling and city form. Within the theme of 'dwelling as building stone of the city' it focuses on the secondary space of Berlin. This type of city space, that forms a large part of the present-day metropolis, is underexposed in the debates about the development of the city. The investigation begins exactly there, where the discussion on how to develop a city is still very much unclear. The project tries to determine the secondary space of Berlin in order to get a clear image on what characteristics and potentials of this type of city are. The 'Zwischenstadt', a term introduced by Thomas Sieverts, provides a clear analogy with the space looked for in Berlin. The term addresses the decentralization of the compact historical European city and shows the development of a form of urbanity which he describes as the urbanised landscape or the landscaped city. The polycentric character of the metropolis of Berlin has led to a a similar kind of character. The expansion of the different centers within the region has resulted in a cityform where the characteristics, investigated under the term 'in-between city', are evidently useful to determine secondary space. These different characteristics are projected on the city of Berlin. It creates a layered map of the investigated space and thereby forms the first step into this project. A closer look on the uncovered city type shows a remarkably distinctive structure of a peripheral type of building block. This block has come to exist of a large diversity of different building types as a result of the different development phases it went through. The adapted building block is omnipresent in the secondary space. The blocktype is being analyzed by means of two case studies. This forms the basis for a strategy which envisions the evolution of the block with a collective type of dwelling. The strategy is being formed by analyzing bourgeoisie multi-family homes, from the period of 1895 until 1918, which are able to create a high quality living environment within this allotment type. The typology, developed just before modernism became the leading paradigm, is able to house this higher class in the city with very refined housing plans. As a result of the rationalization and standardization of the plans in subsequent periods this refinement is nowadays less and less present. This graduation project aims to overcome the resulted gap in the development of the upper middle class multi-family home by learning from the refinement of the bourgeoisie apartments from around 1900. This is being used to give an insight in the possible evolution of the block type and results in the design of three multi-family homes within an adapted building block in Berlin.