The Distilleria Nardini is enlarging to include a new auditorium, in an underground area, and two transparent elliptical structures that hover above a stretch of water surrounded by American oaks planted in the seventies. A ramp leads visitors to a below-ground section with rough-cut walls whose “skylights” give onto the water feature filtering light from above. The entrance, theatre and other spaces have been dug out of a bank of alluvional gravel.
The most striking feature of the complex, however, is the two, different size “bubbles”. Set at an angle to each other, they rest on slender slanting columns rising from the reinforced concrete walls of the underground hall. “The whole project needed a base and a backbone. The slanting elevator immediately appeared the solution”, says Massimiliano Fuksas. Built on a steel slab, the staircase crosses the water, linking two worlds: one, the light-flooded bubbles (transparent, glazed structures) with right-around views of the park and its research labs; the other, the “submerged” auditorium, carved out of the earth to form a canyon (100 seat auditorium accessed by a ramp that can serve as an outdoor theatre). The two areas can become one single arena surrounded by the irregular line of the sloping walls. Near the entrance, the water throws up reflections under the bubbles. The underwater skylights that filter daylight to the underground spaces at night become light sources. The asymmetry of the architectural elements creates a variety of views: the staggered ellipses, the slanted elevation, the suspended staircase, and the turns of the entrance ramp.
Key structural elements include the rough cut reinforced concrete load bearing walls of the underground levels, the ellipse-shaped “bubbles” with curved steel rib superstructure, and the H-beams of the foundation that give the bubbles their curved shape. As well as connecting all levels, the slanting elevator shaft constitutes the support point for the floors. The first underground level is a slab of fair-faced reinforced concrete. The steel lattice structure on the ground floor rests against the outer reinforced concrete walls. At the centre, it is supported by two reinforced concrete structural partitions, and the elevator shaft. The glass of the upper half of the bubble is transparent while the lower part below the floor is opaque. The whole structural project is dictated by the requirements of the glazing component. Indeed the degree of curvature required by the project was an initial technical challenge. Rather than anchored to the steel structure, the glass panels are point-supported by rounded joints that absorb the tolerances of both structure and glazing, and compensate for the dilation differences of the materials. This system does away with the usual safety support systems required for cantilevered surfaces subject to tensile stresses. The independent glass balustrade follows the curvature of the main structure.
Spatial distribution allows for high energy savings. Different exposure conditions, the use of the thermal inertia created between the external glazed volumes and underground spaces makes heating and cooling possible simultaneously in different parts of the building. A customised hydraulic cooling system transfers heat to the heating system with net savings. This multi-purpose heat-recovery cooling plant, especially designed by Climaveneta for this complex, produces hot water for domestic uses and cool water for the air conditioning system. It is designed to recover heat during summer, supplying hot and cold water on two different circuits – air conditioning and heating – regardless of the outside temperature. The primary energy source is a nearby well water.
The “selective” laminated glazing of the bubbles is more transparent to light rays than infrared frequencies, ensuring high energy ratings. Forced-air and radiant panel heating prevent misting of the glass during the winter and ensure comfort-zone temperatures during summer. Radiation heat exchange balances convective air exchange when the air conditioning is working, and ensures low energy consumption when the building is empty.
In the auditorium, air vents in the step risers convey cool air from the empty space immediately beneath that serves as a plenum. Air is extracted through the service zones.
In the bubbles, air enters around the sides, the empty under-floor space acting also here as a plenum. Air exchange takes place in the air space between the two glass layers and so does not cause any passenger discomfort. The artificial lake covering the underground structure creates a microclimate. Evaporation during the summer cools down the underground spaces and the aboveground area. An osmotic filtering system ensures constant water circulation.