The Synthesis line of ReDesigning Deltas is focused on integration and academic consolidation of the other lines of enquiry in the program, such as the Joint Fact Finding and the Design Study, to prepare an international, 5-year research program. To do so, the Synergy line describes the outcomes of deliverables for their scope and validity, but also analyzes and develops methods. H+N+S Landscape Architects has been commissioned to review the instruments of the Dutch Layers approach (a planning instrument) and the Casco Model (an instrumental elaboration of the Layers Approach).

Although both have become mainstream over the last decades, the question remains how they can be made instrumental for design. H+N+S analyzed the instruments (that originated from their offices) on their perspective and how they were used at the national (Belvedere, Ecological Main Structure, Room for the River) regional and local scale (VINEX and the Green-Blue Buffer in Delfland, with the design of Berkel-Rodenrijs). Here the perspective for the drawing of the casco became clear, as green structure or in coherence with the urban areas; Belvedere is the national program for historical values as base of development used in the regional project of De Nieuwe Hollandsche Waterlinie and the local design of the Diefdijk. The aspect of historical qualities in multifunctional land use (preservation and recreation) proved to be a key strategy in creating a new spatial order; while the ecological main structure was a driver for the Room for the River-program, developed on a local scale in Nijmegen.

The outcomes of the analysis of H+N+S are used in the methodology workshop of the Design Study, where a new interpretation of the Casco Model will be used by the design-teams. The Synthesis Line also houses other contributions focused on methods of different disciplinary fields, such as scenario-planning, landscape design and spatial planning.