It is a truism that a window needs glass to become a window. But when a glass producer with 350 years of history behind it meets a passionate window manufacturer, things are suddenly different: Saint-Gobain’s Fabrice Didier and Finstral’s Florian Oberrauch talk about light and life, about solar irradiation and Louis XIV, about innovation, lightness and perseverance. And about glass, of course. And windows. Portrait of an encounter.

If we understand architecture as a language that creates very different narratives according to its context, then windows must also change depending upon their context. Box-type windows, for example, do not recount the story of democratic transparency, while large glass surfaces do not necessarily accord with the history of a 500-year-old Swiss farm located in a mountain landscape. This in turn means that architects as storytellers can draw on a very wide choice – of window material that in its turn consists of a vast range of window and sash frames... and glass. Upon what exactly does this connection depend? To answer this question, a glass expert from Paris met a window expert from Unterinn on South Tyrol’s Ritten mountain: Fabrice Didier, vice-president of the Saint-Gobain group, is responsible for marketing and was previously responsible for the company’s glass business in Germany. Florian Oberrauch, a nephew of Finstral founder Hans Oberrauch, sits on the board of directors and is responsible for production and logistics.

The venue is Lower Franconia. Didier and Oberrauch meet at the Finstral insulation glass factory in Gochsheim, right in the middle of this German province, in an industrial area that was once green fields: easily accessible, but only by motorway. First of all, our host André Mehlhorn, member of the management board of Finstral Deutschland, leads us into the meeting room on the second floor before inviting us on a tour of the factory building. Up here we are of course sitting behind Finstral windows and therefore behind glass made by Saint- Gobain – as, for the past four years, Europe’s most highly certified window manufacturer has exclusively been using panes from Europe’s leading flat glass producer. It is a hot day and, despite the solar control glass, the ventilation is working flat out. Later, when the talk turns to glass as a vector of innovation, Florian Oberrauch states “We cannot be satisfied with this – things have to be better in energy terms.” He agrees with Fabrice Didier that this has to happen – and soon. But before we look ahead to smart windows that can adapt to the time of day and the season, we look back. How did the story of French glass, which has made window history, actually begin? And where?

It all began – as with so much in modern France - with Louis XIV who, on the one hand, caused both his court and absolutism to shine in Europe – but who was on the other much less narcissistic than the pomp and splendour of the Palace of Versailles might suggest. Fabrice Didier leans forward and his voice softens. You can tell that he knows very well how much his company owes to the “Sun King”. “When Louis XIV designed Versailles,” explains Didier, “his aim was not simply to build a memorial to himself. His main concern was to promote the most innovative technologies of the day, bringing them together in one place and thus making them visible.” Louis’s vision of completely new water features required completely new types of pump. While for the famous Hall of Mirrors he needed mirror glass that had never before existed in this form and size. “The idea was that more light should enter the rooms, so that not so many candles had to be lit in the early afternoon. They created large amounts of smoke.”

In 1665 Louis’s Minister of Finance, Colbert, was tasked with founding a mirror glass factory: the origin of the company that later became Saint-Gobain. Didier calls the first location in Paris a “pilot plant”. But, as is so often the case, the beginning was difficult. “In the first year it was planned to produce 1,000 glass plates”, says Fabrice Didier. “But, of the 1,000 pieces, 999 broke. The new factory itself immediately went bankrupt. But then the engineer responsible marched out to Versailles and said, Wait a moment. One plate has survived, which shows that the production parameters were not constant. If we can understand these parameters better, we can turn one plate into ten, then a hundred, then a thousand.” Colbert was convinced and continued with the financing. The engineer discovered that the surface upon which the cylindrically blown glass was cut, rolled flat and allowed to cool should not itself be cold. The temperature difference was otherwise simply too great: the glass would break. So they warmed the table and, some time later, invented the revolutionary table rolling process, whereby the melted glass is poured and rolled directly on the hot table. Shortly thereafter the factory moved to Picardy in northern France, to the village of Saint-Gobain after which the company is named. This was in 1692. “From that moment on, we have known success”, says Fabrice Didier, pausing for a moment. “I still tell this story today, preferably to our staff in the research department. I want to show them that sometimes you have to persevere. Then as now.” In 1993, after 301 years, Saint-Gobain closed its plant in Saint-Gobain; the company headquarters, long located in Paris, are now being rebuilt – using plenty of glass, of course. The spirit of the early days can still be felt today. “It makes us proud that Saint-Gobain has for the last seven years been voted among the world’s 100 most innovative companies,” says Fabrice Didier. “Always think ahead, trying out new things and pushing forward... You can say that this attitude is part of our genetic make-up.”

Perhaps the question of the impulse behind it is simply: why all this, why such a passion for glass for windows and windows for glass? “We need and make windows,” replies Fabrice Didier, “because people need natural light. Without light we would suffer a nervous collapse. A child’s brain needs at least 300 lux for at least three hours a day in order to develop. There is no life without light.” Many architects know this, of course, and their desire to create stories using as much glass as possible remains unbroken. And Didier is sure that Finstral, more than other window manufacturers, has a special sense for light. “The frame plays an important role. But the profiles are narrow, so the glass is at least as crucial. Finstral recounts a great deal using glass and light, more than other window manufacturers.” Fabrice Didier, top manager in a global corporation with nearly 180,000 employees and many products other than glass, speaks this phrase – one that seems to come from his deepest soul. While he states this about the Oberrauchs and Finstral, it is at least just as much about himself: “Market leadership is good, innovation is great. But loving and living glass is the finest of all.”