For a long time, the Westraven office building in Utrecht was a heavy, closed and stuffy colossus that was due to be demolished. The revitalization that was nevertheless chosen had to at least reflect the modern values of the user, the Ministry of Infrastructure and the Environment: openness, transparency, professionalism and sustainability. The proposals made by cepezed matched the requirements best. The more than 27,000 sqm tower was stripped back to the concrete skeleton and provided with five enormous voids that bring a generous incidence of natural light and a feeling of spaciousness to the building and also contribute to good orientation. To create a panoramic view and allow a lavish amount of daylight to enter, the new façades are glazed for the most part. Elements that can be opened make natural ventilation possible. A double façade primarily of Teflon-coated glass-fibre membrane prevents wind nuisance, functions as a sunscreen that leaves the view intact and also forms an aesthetic component that generates strong horizontal articulation. The renewed climate system consists mainly of projectspecific climate ceilings between the concrete floor joists. A 23,000 sqm extension at the foot consists of five triangular office wings that offer as many people as possible a view of the adjacent canal. The triangles are connected at the base by an efficient circulation artery and at the rounded corners by a large, all-round conservatory where the spaces between the wings have been roofed over transparently. With an ornamental pond on all sides, the complex is firmly anchored in park-like surroundings covering an area of around 3,000 sqm. The ensemble is characterized by a large variety of sustainability aspects. Besides the double façade already mentioned and climate ceilings, these include elements such as a geothermal pump, concrete core activation in the new-build floors, a lay-out divided into various climate zones related to use and a series of integrated design solutions, which are not only aesthetically pleasing and functional but also save considerably on materials. Westraven has received many nominations and awards for sustainability and also for its architecture. In addition, various heavyweights from the Dutch construction world have described the project as one of the most successful in recent years. The former chairman of the construction trade association Bouwend Nederland, Eelco Brinkman, said: ‘Everything is just right: the location, the comfort, the energy consumption. A project like this demonstrates that quality is worth it.’

utrecht / the netherlands

government buildings agency