The Knoopkazerne in the center of Utrecht dates from 1989 and served for decades as headquarters for the Royal Netherlands Army. The building has now been radically transformed into a combined office and meeting center for the national government. Commissioned by the consortium R Creators with Strukton, Ballast Nedam and Facilicom, cepezed produced the architectural design. Fokkema & Partners Architects was involved for the interior design and Rijnboutt for the urban design component.
The original complex was characterized by a pronounced multitude of volumes with varying heights and floor dimen- sions as well as meandering façades with a smoke glass sun-blind. In the redevelopment designed by cepezed, drastic changes have been combined with partial demolition, new- build expansion and a completely new urban embedding over multiple height levels. A lively, transparent and double-height plinth will include general functions such as the entrance zone, a café, restaurant and landing work places.
The existing construction of twelve storeys houses all office functions, with the characteristic octagonal concrete columns being left in sight. Removal of the many inner walls has resulted in more light, air, openness and transparency. Hybrid ceiling islands specially engineered for the project in existing buildings mean that no lowered ceilings are needed and that maximum spatiality is created despite the limited floor height. The meeting centre is located in an extension with eight high storeys. The new and existing buildings unite in a transparent atrium and a transport zone with elevators and stairs. In the conference centre, pausing areas and guest workspaces are located adjacent to and in open connection with the atrium. For a pleasant quiescence, the meeting rooms are more remote from the atrium.
The complex has a taut outer skin with vertical articulation that binds the different parts together into one whole. In this way, inlets in the original building contour will form voids that contribute to the internal spatial quality.
Sustainability is very important and is achieved through, among other things, an optimal reuse of the existing build- ing, a high degree of flexibility, natural ventilation and, for example, the use of triple glazing, approved materials and a partly green roof. A large surface of solar panels, use of the cumulative mass of the existing concrete construction and an energy system based on recirculation and heat recovery are, just like automatic presence detection for the light and CO2-measurement for climate control, important additional aspects.