The Werkspoor District of Utrecht houses an immense industrial warehouse of 175 metres long. The factory hall is, together with several other buildings, part of the old Werkspoor. Large-scale steel constructions were processed here for civil engineering. Most of the buildings have meanwhile been demolished, but together with the Werkspoorkathedraal, the Werkspoor Factory acts as a catalyst of the area and it is a symbol for the circular area development that is taking place here in the coming years. Zecc transformed the monumental industrial warehouse of the Werkspoor Factory into a sustainable and circular multi-lessee business building for the creative manufacturing industry. It now houses an active community of approximately forty businesses. From beer brewery De Leckere to 3D printing. The idea was to create a new structure within the free industrial space of 175x25x15 metres where businesses of various scopes and with various activities can establish themselves. Without prejudicing the industrial character, views and the length effect. In order to achieve this high level of ambition, ample surface area was added locally whilst at other locations as much spaciousness as possible was preserved. It is now a factory of several businesses, spaciously and visually connected with each other. The signature skylight and continuing steel window frames were restored and equipped with insulating glass. The open floor on the 2nd and 3rd floor was filled with flexible work units of wood and glass. In association with Sustainer Homes, Zecc devised a modular building system of wooden building blocks that can easily be adjusted or repositioned. The system is 100% circular and is assembled without screw and/or glue connections. The whole forms a spacious world with small bridges, stairs and views. Future use is anticipated with the interventions in the façades and the added new structure of open floors. The Werkspoor Factory has considerable influence on the activation of the area and the people who work, think, live and manufacture here together. The building stimulates entrepreneurship, innovation and is open to the surroundings. The synergy between design and programming turns this ambition into reality. Big-hearted cooperation resulted in a big-hearted building where, apart from lessees, external visitors are also welcome. Meeting is facilitated by spaciously set up traffic areas. An event space and skybox offer room for meetings, coffee bar Pluck is present in the main lobby, which is accessible to everyone. To strengthen the relationship with the public, the history and the neighbouring district, the ‘Museum van Zuilen’ was housed in the Werkspoor Factory. This is already resulting in wonderful cross-connections and a tangible energy! The building works, it is lively because it was designed for and by cooperating designers. It stimulates interaction and is flexible in use. The sustainability of the construction and the possibility of repurposing in the future give its beauty an additional dimension. Hopefully, it will inspire others to take the step to a sustainable development.