Slussen is a mixed used area in the central part of Stockholm. Slussen includes Stockholm’s second busiest public transportation hub, a floodgate regulating water levels between the lakes Saltsjön and Mälaren and it also connects the island Södermalm with Gamla Stan. The present Slussen was constructed in the 1930th and needs to be upgraded to meet todays and future demands. The architecture firm Foster+Partner has designed the new Slussen. The main part of the project is implemented as a client design contract. The design is however carried out in close cooperation between the consultant, the client and the contractor. All designs are prepared and submitted as 3D models with detail information included and available in the design elements. Extremely few traditional blueprints are prepared.