The Directorate-General for Public Works and Water Management (Rijkswaterstaat) tendered the extension of the lock with a DBFMO contract. That means that those market parties are responsible for the design (D), the building (B), financing (F), maintenance (M) and Operation (O). To guarantee spatial quality during the tender, Bureau B+B composed an Esthetical Demands Program. The most important functions of the EDP are enhancing the landscapes’ identity, increasing usability and creating consensus. The lock complex in IJmuiden consists of four different locks, the oldest dating from 1876. The youngest will be completed in 2019. Consequently, the locks differ in shape and size. The challenge lies in connecting the different parts of the lock complex, without compromising their separate identities. In the concept ‘Machine+Dune’ the original dune landscape returns to the lock islands.

Wild, flowering dune vegetation is sowed on the islands, creating a high contrast with the technical environment. To prove that functionality and aesthetics don’t exclude each other, all technique is designed in a way that clearly shows the functioning of the machine. The lock creates a connection between different waterways. At the same time, it is an important link in the land infrastructure. Cars, bikes and pedestrians cross the canal over the lock. Nature and recreation also demand attention. The lock islands serve as stepping stones in the National Ecological Network. Plants and wildlife migrate north and south using the islands. Besides that, there are recreational demands on the world’s largest lock complex, causing a conflict between the safety and accessibility of the locks. All these aspects are pieces of a puzzle that must be fit together with great care. The EDP is the manual to this puzzle.