MINNAERT BUILDING

Utrecht, The Netherlands

1994-97

Neutelings Riedijk Architecten

Rainwater pours through the roof of the Minnaert Building on the Uithof campus extension of the University of Utrecht to cascade noisily into a 150 by 30 foot basin filling half the building's cavernous central hall. This is on the second floor main circulation level, at which the building is connected by bridges to its neighbors. The water in the pool feeds a circulatory system by which the temperatures are controlled throughout the building, which houses facilities for three departments, including that of geophysics, and a restaurant serving the entire northwestern corner of the campus. The original program for the building consisted of a detailed schedule of spaces plus a percentage extra for circulation, services and 'architecture.' The architects decided to concentrate all this space in the unasked-for central hall and to use the hall for a dramatically novel form of energy-efficient climatic control. With its laboratories and library packed with computers, the building needs no extra heating, even in the extremes of winter. Instead its spaces are cooled, and heat is conducted away from them, by circulating the rainwater through panels suspended below the ceilings. To prevent the water becoming too warm to serve this function in summer, it is pumped onto the roof to be cooled by the night air before plunging back into the pool. Rising and falling levels of water in the pool are emphasized by the sloping 'beach' which connects the bottom of the pool with the floor of the hall. Construction consists of pre-cast, ochre-pigmented concrete slabs. Those forming the roof are suspended below pre-cast beams. (The steel mullions of strip windows and letters spelling MINNAERT are structural too.) Insulation is external to the concrete units, and the elevations are clad outside of this with a rough, rust-colored sprayed concrete. This is intended to emphasize the monolithic character of construction inside while also being 'wrinkled' to express that it is only a skin. Rather resembling an upward extrusion of earth, the effect seems appropriate to a department of geophysics. Shades of green: Low energy/high performance; total life cycle costing

[photo credits: Minnaert 1, 2 by Hermann H. Van Doorn]