Swiss Life Brannhof – historic building structure and comprehensive refurbishment

Since March 2020, Swiss Life has been renovating properties 75 and 79 in Zurich's Bahnhofstrasse. In the summer of 2021, the historic building complex was renamed "Swiss Life Brannhof" – both as an homage to Julius Brann, the pioneer and founder of the department store opened in 1912, and as a reference to the structural changes and new use concept of Swiss Life. Around 4600 m² of flexible retail space will be created here from the first basement to the first floor, while the upper floors, with around 5600 m², are intended for offices. A café with a gallery floor is planned at the corner of Bahnhofstrasse 79 and Pestalozziwiese.

A great deal has happened in recent months behind the tarpaulin-covered scaffolding at Swiss Life Brannhof's construction site. One of the milestones was the completion of the civil engineering work. During the partial basement and the technically very elaborate securing of the excavation pit for a third basement, the builders were given surprising insights into earlier construction methods: when they broke off the floor slabs, they unexpectedly encountered railway tracks. Together with other residual materials, they had probably been used as reinforcement in 1910 to reinforce the concrete slabs in an inexpensive way. However, the builders were unable to find a certificate box from Brann's time, but they deposited a time capsule with Swiss Life documents when the foundation stone was laid.

"The fascinating thing about this renovation project is the diversity in which there are still historical building structures from the 1910, 1920s and early 1930s," says Christoph Kling, Project Manager Construction, Swiss Life Asset Managers. “There are not many buildings of this size on Bahnhofstrasse that are undergoing total renovation and that have preserved so much of their original fabric.” This is despite the fact that the building has been renovated several times in the decades after Brann. During the renovation, the original re-emerged behind countless layers and in varying condition. A good example of this is the large, round pillars on the ground floor: initially they were covered with plaster and stucco edges, then they were clad in mosaic tiles, later they were coated in new plaster, all kinds of paints, and finally even PVC. Now the original columns are being cleaned up again. But the preservation of the historical substance is not always successful. For example, it was not possible to restore the herringbone parquet because so much glue had been applied, and it was so worn and contaminated from all the subsequently applied floor coverings that it had to be removed.

Other components require extensive restoration, such as the wooden lattice windows dating back to 1911 on some upper floors, or they need to be brought out of the shadows, such as the old staircases on Lintheschergasse with their original floor and wall tiles. The 10 000 stained-glass windows by Otto Morach are also being restored. Likewise, there will be an atrium again, as seen in old photographs of the Brann department store, and as was so typical of the early department stores. However, the atrium was closed long ago in favour of more retail space. It is now being rebuilt to provide optimal lighting for the office space on the upper floors.

A lot of things are being done in parallel on this construction site. While the excavator is still standing in the basement and cranes are protruding from the inside, the windows are being refurbished, dormers in the roof are being completed, stairwells are being concreted and ventilation ducts and heating pipes are already being installed.

The scaffolding and the printed scaffolding cladding are currently being removed and gradually providing a view of Swiss Life Brannhof with its renovated sandstone façade. The large windows will then be installed on the ground floor. "Although they are all new, they should have a certain historical connection. That's why we chose architectural bronze frames. This material ages very nicely and is durable”, as Christoph Kling points out.

Meanwhile, the interior work continues. One of the most complex construction sites is the new hall on Lintheschergasse. Here, the restored stained-glass windows must be installed and additional thermal glazing fitted from the inside. The roof and dormers will be installed above the hall, and building services, fire protection equipment and corresponding tests of the systems are still to follow, as are the installation of high-quality stucco veneziano plaster and special LED lighting in the hall. So there is still a lot to do before the targeted retail space opens in autumn 2023.

_{Karin Pache, Communications, Swiss Life Asset Managers}