From Concrete to Glass

– Renovating Compact Building 6/70

Renovate a building with floor space equivalent to six soccer fields and a height of about 50 meters as fast as possible – that was the plan that was to be implemented starting in 1991. The former production building 6/70 on today’s Carl-Zeiss-Promenade was to become the new headquarters of Carl Zeiss Jena. The challenge involved moving the production of other Carl Zeiss sites in Jena, including machines, personnel, and furnishings, into building 70 without interrupting production.

Building 70 had very little charm in 1991 – a colossus made of concrete, steel doors and endless corridors. Thus, the modernization of the complex was undertaken under the motto “light, air, and space”. “Our employees should be able to see a piece of the sky from every single workplace,” was the wish expressed by the executive board at the time.


The concrete front of the south façade (left) on Building 6/70 around 1978.

The concrete front of the south façade (left) on Building 6/70 around 1978.

The concrete front of the south façade (left) on Building 6/70 around 1978.
In 1995, all 173 concrete slabs were removed from the south façade by crane.

In 1995, all 173 concrete slabs were removed from the south façade by crane.

In 1995, all 173 concrete slabs were removed from the south façade by crane.
Renovation work inside Building 70.

Renovation work inside Building 70.

Renovation work inside Building 70.
Ceiling work in the interior of Building 70.

Ceiling work in the interior of Building 70.

Ceiling work in the interior of Building 70.
The glass front of the south façade of Building 70 in 2006.

The glass front of the south façade of Building 70 in 2006.

The glass front of the south façade of Building 70 in 2006.
The two glass elevators have been providing a view overlooking the roofs of Jena since 1995.

The two glass elevators have been providing a view overlooking the roofs of Jena since 1995.

The two glass elevators have been providing a view overlooking the roofs of Jena since 1995.

Challenges of a Free Market Economy

The free market economy was still new territory in 1991 and posed several challenges during the remodeling of Building 70. All of the bids by the trades and other suppliers had to be compared to a competing bid with regard to quality and price. Prior to 1989, such a wide range of service providers did not exist. In addition, time was of the essence in the modernization of the building – not only because of added costs due to the outsourced operations, but also because more renovation proved necessary than originally planned.


Renovation Work and Involuntary Hikes

The “woodpecker,” a hydraulic demolition hammer, was responsible for the rough work inside the building. It removed the massive walls of the former corridors that had been designed as an escape tunnel. Intermediate stories were added to the east and west façades of the south building. To ensure that ZEISS quality was still produced with its customary quality in the rooms adjoining the construction sites, extensive work was necessary to separate the areas.

Many walls and ceilings were given a new coat of paint, and the floors were completely replaced. Tradesmen laid electricity cables, installed new gas lines, and modernized the ventilation systems. While the sanitary facilities were being repaired, the Zeissians were not allowed to use the toilets in their own areas of the building. In 1992, the employee magazine mentioned the “involuntary hikes” that the staff in some areas had to take to find a restroom. They even had to go without running water during the times when the water lines were being rerouted.

From 1993 to 1995, 173 concrete slabs were removed from the south façade and replaced by a glass front.


Carl Zeiss in Jena Receives its New Calling Card

By the end of 1996, the southern part of Building 70 was almost completely modernized. In 1994, the new Carl Zeiss logo was affixed to the roof, an external symbol of the reunification of the sites in the East and West. Seven years later, it was replaced by an illuminated logo. A total of 15 existing elevators put the finishing touches on the “Glass Twins,” which have afforded a view overlooking the roofs of Jena since 1995. Together with the logo towering over them, they have been the company’s calling card at the Jena site ever since.