The American architect Robert Venturi wrote in 1966 the book Complexity and Contradiction in Architecture. The book was one of the first that critiqued the 'either-or' attitude of Modernism, which arose from the selective 'less is more' dogma. Venturi suggested that the complexities and contradictions should be accepted thereby creating a richer architecture; 'less is a bore". When complexities and contradictions are allowed a conflict is created that has an effect on space. One of the results is an intermediate space that Venturi calls "poché". This space is the residual space between two dominant areas. Venturi attributes several qualities to these residual spaces ranging from the conditioning of light to the articulation of spaces. This study continues on Venturi's "poché" through a retrospective study on the in-between spaces of Van Eyck and the Smithsons. This study is divided into a theoretical and a design research. The theoretical research starts with a discussion of the works of Peter and Alison Smithson and Aldo van Eyck, from which their primary motives are distilled. Using these motives their projects are analyzed and an outline is formed on how the Smithsons and Van Eyck's theoretical fundamentals manifest physically. From both the Smithsons and Van Eyck four projects are selected. These eight projects lead to the main conclusions, as they are one of the main projects in the overall architectural discourse. The in-between space of the Smithsons is based on their ceaseless quest for a new social domain as the street had lost its social function in the city. In their designs this results not only in large voids between buildings - the intervals - but also widened galleries that provide the ground for social expression - the so-called 'streets-in-the-air'. Whereas the Smithsons pursuit a dichotomous model, the work of Aldo van Eyck is about a endless network of related spaces and objects. With its 'Twin Phenomena' Van Eyck embraces the relativity of everything; everything must be related to each other in a reciprocal way. Van Eyck's inbetween space is an articulating space where the surrounding entities are simultaneously present in a dedicated architectural appearance. The studied principles of both the Smithsons and Van Eyck play an important role in the design research. But while the principles can be traced, there is a divergence from how the Smithsons and Van Eyck have used these principles. The in-between spaces in the design are not only the result of external, but also of internal complexities and contradictions. While some of the complexities arise from eg the inner-city location, complexity also arose from the anticipated user of the building, Stichting Exodus, a reintegration program for ex-prisoners. This adds additional complexity in how to incorporate this socially undesirable group within a neighborhood. The design is based upon a clearly defined order by creating three powerful gestures. Gestures, which have been derived from the Smithsons' repetoire in wich by starting with several powerful gestures a void is created, the interval. Allowing internal and external complexities then breaks this powerful basic order. The poché spaces that result from this exercitation are then approached from the studied in-between spaces of Van Eyck and the Smithsons. Existing walls are being retained to organize spaces, for example in the public domain where they act as transitional areas between public and private. Incorporating the phase-system used by Stichting Exodus varies these transitions between public and private. Within the design a promotion to a subsequent phase results not only in an improvement in the offered facilities - a private bathroom, kitchen, etc. - but also results in a less clearly defined public space. The in-between spaces of Van Eyck and the Smithsons are not only based upon historical significance, but also add pedagogical features. This project illustrates the possibilities of Venturi's attitude towards complexities and contradictions and the consequence it can have in an architectural design. It leads to a different approach of in-between spaces than that of the Smithsons and Van Eyck, an approach that follows from considering both external as well as internal complexities and contradictions. Besides the articulating qualities that Venturi ascribes to poché, one may conclude that in-between spaces have more to offer besides qualities. Notably Van Eyck's theory illustrated the mediating role of in-between spaces, which makes the 'in-between' not only a construct useful for a building but also a suitable strategy in urban design.