While the department stores are in heavy weather, the need for housing is increasing everyday. Redesigning old department stores to be used as housing is a necessary solution. So how to fit appartments in a large building, that is so unfit to be used for housing in its current condition? While researching the V&D department store in Leiden it was confirmed that the building needed thorough changes to adapt to a housing function.To adapt the building for its new function the building block is changed into an open-block structure. Resembling the structure used in most high density urban environments. At the same time this open structure compliments the already existing connection between the Aalmarkt and Breestraat side of the building. While opening up the building it was important to preserve its valuable elements, and where elements were removed or introduced, to relate to the original department store. The result is a building with a stepped open-block structure to balance the amount of light, floorspace and functions. The open structure creates terraces for the apartments which also serve as traffic space. An open public courtyard is introduced on the ground floor, reintroducing the old connection through the building. The inside of the building and the Marsmansteeg get new facades, using materials that relate to the main facade at the Aalmarkt. Using the valuable old V&D store a building is created which mixes public functions and housing in the heart of the city.