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In addition to office space for 450 workers, the building houses state archives, a restaurant, a conference center, a fitness center, and a secure computer center for managing all of Zeeland's sluice-gates in an emergency.

The new RWS office sets an example in sustainable construction. The Amsterdam design firm, Architectenbureau Paul de Ruiter b.v., applied familiar design techniques in innovative ways to make the building efficient in energy use without interfering with its economic feasibility or architectonic image.

The building makes use of passive solar energy, with heat and cold stored both in the structure and below it. "Climate facades" sport variously angled louvers to protect the view glazing from overheating. Multiple atria augment daylight, and sustainable and techniques materials were chosen for construction.

So-called "active concrete" refers to a technique for stabilizing temperature within the thermal mass of the structure while guaranteeing interior comfort levels. A prefabricated, 12-inch- (30 centimeter-) high concrete floor system is formed with "conduit" for air distribution, integrating electrical and data systems.

The concrete mass of the floor and ceilings absorbs a large proportion of the heat generated within the office space. The concrete is, in turn, cooled by circulated air, producing a comfortable radiant cooling effect for occupants.

Additional thermal storage occurs below grade. In the winter, water in an aquifer is chilled and used the following summer to cool the building. In reverse, the excess summer heat is stored in a separate part of the aquifer to be used to heat the building during the following winter.

Heat exchangers manage the distribution of heat and cold between below-grade storage and the interior spaces and between spaces with differing thermal needs. This energy system is thought to be 40 to 50 percent more efficient in energy use than conventional systems.

The exposed concrete floors and ceilings eliminate the need for air ducts and a dropped ceiling. This reduces the floor-to-floor height from 11 feet-10 inches to 11 feet-2 inches (3.6 to 3.4 meters) while increasing the net room height from 8 feet-6 inches to 10 feet-2 inches (2.6 to 3.1 meters). This extra ceiling height allows for higher glazing and greater daylight penetration and, therefore, less dependence on electric lights.

This modern building, by its transparency and innovative construction, makes a forum for stimulating the communication between workers. Its flexible construction system will make it adaptable in the future as interior space needs change in ways not yet envisioned.

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SUBSCRIPTION SAMPLE New office building for Rijkswaterstaat Zeeland (RWS) in Middelburg, The Netherlands, designed by Architectenbureau Paul de Ruiter b.v. Photo: Rob't Hart Fotografie Views along the canal from RWS. Photo: Rob 't Hart Fotografie Ground floor plan, RWS. Image: Architectenbureau Paul de Ruiter b.v. Cross section looking east, RWS. Image: Architectenbureau Paul de Ruiter b.v. Concrete floors and ceilings provide radiant heat or cold, depending on season. Image: Architectenbureau Paul de Ruiter b.v. Transparency of RWS at night. Photo: Rob 't Hart Fotografie Open daylit spaces provide visual comfort regardless of orientation. Photo: Rob 't Hart Fotografie Canal-side glazed corridor. Photo: Rob 't Hart Fotografie   Click on thumbnail images to view full-size pictures.