VILLI - Glass Tiles & Mosaic

For the exterior façade, tiled with VILLIglas, of the Luwoge/Gewoge (BASF) building, the architectural firm of AllmannSattlerWappner from Munich was awarded the German Façade Prize.

Thousands of small-sized glass tiles make up the façade of the Luwoge/Gewoge Service Center in Ludwigshafen. What appears to be massive in dimension is, in fact, ventilated at rear, based on the Verotec Futur façade system, which opens up a range of new architectural expressions.

One of the strong points of the Munich-based engineering office AllmannSattlerWappner is, without any doubt, their experimenting with conventions - that is, conventions of perception and structural engineering. Every project represents a subtle surprise of ambivalence, which adapts familiar motifs while, at the same time, qualifying them in new ways.

This approach might border on the subversive, but it is really about attaching a positive charge to structures that could have turned out quite different. But AllmannSattlerWappner are not into "off-the-rack architecture"; instead, everything is customized - with a meticulous eye for details.

Otherwise often sacrificed for practicalities and degraded to something marginal, the power of architecture lies in the detail, as this engineering office demonstrates - even if the detail is no more than the constancy of a façade grid made up of tiny elements. Rather than indulging in a big spectacle, they celebrate delicate and multifaceted architecture.

And this is also true of the Ludwigshafen project. Luwoge/Gewoge, a subsidiary of BASF, had launched a competition for the design of its new service center, which AllmannSattlerWappner won. About three years after starting work on the final design plans, the comb-shaped building is finished, moved in and fully operational.

Essentially, it is an administrative building for the housing company Luwoge/Gewoge as well as BASF's health-insurance fund Fortesnova - in other words, it was a familiar task for the architects, yet they came up with a unique and specific end product.

Their approach was to divide the property into parallel strips of varying functionality - a principle that instills order, which permeates the entire design.

With the building located along a busy street, the architects have developed a multipart design of five office modules that are docked to a slim cross-flank at the north end. This junction serves as a spatial link between the three-storey office modules, but also houses conference rooms, technical installations and entrances.

With a length of 160 meters, the junction also separates the building from the street in the north - it is also the part of the building that the public sees at first.

Think Big

The façade design of the junction, thus, serves an important function: It allows the architects to experiment with solidity and transparency as well as layers and reflection in a masterful manner. Most of the long north façade and the front façades facing west and east is covered by a white reflecting layer which, upon closer inspection, turns out to be a large number of small (48 x 48 mm) VILLI glass tiles.

One might assume that these white enamel-backed and double-fused tiles have been applied directly to the massive structure of reinforced steel. For reasons of heat insulation, building physics and the thermal expansion of materials, however, this is not possible.

This is why they had to find another way of implementing the esthetics of the design - and they found it in the Verotec Futur system, a rear-ventilated façade with supporting plates made of expanded-glass granulates. An elegant solution - after all, the supporting plate has an expansion similar to that of the glass tiles.

Since the concept of Verotec Futur is such that it can be used as a substructure for a variety of covering materials, the use of tiles was an obvious choice.

A special building permit "for this particular individual project" was obtained on condition that the material's long-term behavior had to be monitored.

The 8mm-thick tiles made by the Austrian company VILLIglas were shipped to the construction site in 30 x 30 cm units of tiles preset on mesh sheets. Then, they were cemented to the previously mounted and reinforced curtain wall, with special emphasis on ensuring a homogeneous overall appearance.

There was not to be any misalignment of individual mesh sheets. The vertical and horizontal gaps of 1.5-meter integrated and extremely narrow expansion joints (2 mm) were not to be visible either. This required material with a high degree of side adhesion and a color that matched the normal joints. For the purposes of matching the contamination behavior of the two joint sealers, the surface of the expansion joints was carefully sanded.

Transparent-opaque interaction with glass

As monolithic as the tiled areas of the structure may seem, they are balanced by the transparent glazed sections, with each one a storey high. They allow the observer to look into the inside of the junction and reveal its functional lateral and vertical development.

The staggered conference rooms, too, which also serve as support for slim, one-flight stairs, become visible this way. The conference rooms also enrich the building's appearance at night: its bright-green ambience radiates to the outside.

Reflections on the glass tiles always make the building look a bit different by day and night. The glass surface of the post/cross-member structure is set back by the exact thickness of the glass tiles. This is a detail that is crucial to the flat effect of the façade. It is also a good example of the meticulousness with which the architects ensured that their designs maintained the modular dimensions, the joint pattern and the façade connections.

The façades, but also the interior of the Service Center represent extraordinary solutions, which are based on the ability to take existing elements and combine them in ever-new ways. AllmannSattlerWappner have fused structural, formal and spatial innovation with the precision of industrial systems - a strategy that has relied on cooperative efforts from the start.

German Façade Prize 2007.