The glass roof of the Central Branch has been restored to its former splendour
Societe Generale values its architectural heritage full of history
Featuring Art Nouveau elements, the Societe Generale head office, located in the heart of Paris at 29 boulevard Haussmann, is an architectural masterpiece designed at the turn of the 20th century by the architect Jacques Hermant. Its glass roof, created by master stained-glass artist Jacques Galland and listed in the Inventaire Supplémentaire des Monuments Historiques (French Supplementary List of Historic Monuments) is one of the building's key features and has just been undergone a renovation. Real architectural and technical challenge, but also a human one, this major project was a source of great pride for all the teams who have contributed to this achievement.
Photo credit: @vuedici
An ambitious project of colossal proportions
Endow with a dome measuring almost 18 metres in diameter and 27 metres high, the glass roofs is one of the largest in Paris. This renovation, started in 2022, on the lower sections, arches and medallions, completes the restoration work lunched in 2011. During this new and final phase, more than 1,350 panels were renovated, representing around 1,250 square metres of stained glass.
This ambitious project was completed in three and a half years (two years of studies and one and a half years of restoration work) thanks to the help of companies with highly specific skills: a heritage architect qualified to work on historic monuments, exceptional craftsmen, a team of master glaziers, of rope access technicians and of electricians.
A methodical and timeless organisation
The excellence of this project lies in the exemplary organization demonstrated by the teams. Also, each panel of the glass roof was methodically removed with the help of a team of rope access technicians to be taken to the workshop, where it was dismantled, cleaned, repaired (if necessary), repainted and then reassembled by the glass craftsmen, before being re-installed on site. At the same time, the structure of the glass roof was completely cleaned. All the on-site work was carried out overnight, to reopen every morning the branch to employees and customers. This was a major challenge!
This exceptional heritage in the heart of Paris has now been restored to its former splendour, and staff and customers alike will be able to continue to marvel at this majestic glass roof, a witness to the history of the Societe Generale group, for many years to come. No one would even know it existed before entering 29 boulevard Haussmann!
Watch a behind-the-scenes video of this exceptional project, as told by those who made this stunning renovation possible.
The glass roof of the central branch has been restored to its former splendour
Marie ROUSVOAL/Ateliers Duchemin vitraux/General Manager
It is quite an extraordinary adventure to finally be involved in this restoration. Firstly, because this glass roof is in an exceptional building, and is extremely grand and very beautiful. It is not excessive, it is highly decorative, and was there to light up the decor. And above all, you are helping to protect a heritage that Societe Generale is committed to preserving, supporting and enhancing.
Louis BRIERE/Ateliers Duchemin vitraux /Technical Manager
The difficulty here is access. You are on a dome with stained glass windows everywhere, so you must not step on them. Of course you are roped up, but you need to keep your balance. And then you are still 25 metres above the ground.
Marie ROUSVOAL/Ateliers Duchemin vitraux/General Manager
All the panels extracted from the glass roof are taken to the workshop, where they are cleaned and dismantled. Broken parts are replaced or glued, reassembled and painted. Because there is a little specificity, which is that in the lower part, seals are painted with gold, so lead is painted with gold and then repacked to be taken to the site and reinstalled overnight as well. This means monopolising a team, energies and constraints over a long period of time, on a continuous production basis. That is all you will do for six months.
Louis BRIERE/Ateliers Duchemin vitraux /Technical Manager
To access the site, you need a team of rope access technicians with whom you can get along well since they provide you with perfect assistance in terms of safety of course and also help because the surface area is very large, so you also need to have arms to be able to carry the stained glass windows and transport the new panels.
For the restoration of stained glass windows, you need to use precise dimensions that are quite complicated since you really have to choose the precise location to take the dimensions, since they are oblong shapes that have no right angle. So it is quite complex.
Baptiste RIO/Colibri/Joint General Manager
The restoration of the stained glass windows required numerous preliminary operations with the cleaning of the entire glass roof. It is a glass roof that has not been cleaned for a hundred years. The sheer scale of the project meant that rope installations had to be extremely varied and complex in some areas, in order to serve all the zones of the glass roof. The treatment has been complete. Thanks to the techniques used, we were able to reach the entire structure and discover even the smallest details and ornamentation.
Louis BRIERE/Ateliers Duchemin vitraux /Technical Manager
We are very proud to be working on this kind of structure, which is really impressive. You do not get much done in a lifetime of stained glass work.
Elodie DELANNOY/Société Générale/Real-Estate Project Manager
It is pretty rewarding. It is a great source of pride to have been able to work on this kind of historic monument. But also, it must be said that this glass roof has not been restored for 110 years. The glass roof of 29 Haussmann underwent two first restorations of the dome in 2011 and 2014 and here in 2022/2023, the restoration of the lower parts, arches and medallions of the glass roof has been undertaken. This glass roof is one of the largest glass roofs in Paris. The dome is 18 metres in diameter, 27 metres high, so it could be used to house the Luxor obelisk that currently stands on the Place de la Concorde. You could put it under the glass roof. During this phase, we restored over 1,350 panels, representing around 1,250 square metres. This project was carried out over three and a half years, i.e. two years of studies and one and a half years of pure work on site. All the work was done at night, and every morning the branch was reopened to employees and customers. It was a huge challenge. So we had to surround ourselves with companies with very specific skills, an architect qualified to work on listed monuments, exceptional craftsmen, a team of master glassworkers, a team of rope access technicians and a team of electricians. We have made some major discoveries, we have cleaned things that we thought were dark, bronze.
Matthieu DUPONT/Colibri/Site manager
And when you start cleaning them, you can see that behind it is gilding. And then you think, this is extraordinary. The bank is decorated with gold leaf. And in fact, from then on, it was pure joy. It was lovely to see.
Elodie DELANNOY/Société Générale/Real-Estate Project Manager
It has been a technical adventure, but also a human adventure, with great cohesion with the site teams and between the site teams. It is a real source of pride to have been able to work on this project. Over a career, you may not restore a stained-glass window on such a grand scale, and quite simply on such a majestic scale.