TCHOBAN VOSS Architekten’s Ferrum 1 features a sculptural corten steel facade

TCHOBAN VOSS Architekten’s Ferrum 1, an office building in St. Petersburg, Russia, has a complex urban setting and an interesting history. The importance of understanding the cultural and geographical context of a site is an important aspect of the studio’s practice. Sergei Tchoban and Ekkehard Voss, in a joint statement, spoke about the importance of working with the context in which their projects are situated, saying, “Before embarking on a new construction project, we always approach the specific urban situation as something unique and valuable in itself. This is what produces unique architectural solutions. The surrounding urban context guides us to the best possible result, which may be contrasting or discreet, massive or light and delicate.”

While the first visual aspect that one would encounter is the building’s façade, it is important to recount the site’s built history. Situated on the right bank of the Neva opposite the Smolny Cathedral, Ferrum 1 stands on what used to be the Rossiya factory in St. Petersburg's Polustrovo district. The factory complex was built in 1911, during the "industrialisation of the entire country". The factory was built on what used to be the palace and garden, built for Prince Alexander Andreyevich Bezborodko, at the end of the 18th century. The site was utilised, up until the 19th century, as a popular recreation and health resort for the upper class of St. Petersburg. Throughout the industrialisation of the Russian Empire, the Rossiya machine factory occupied large parts of the former garden for the factory premises and production facilities, warehouses and administrative buildings.

The former garden area was lost to the factory, which has been closed for a long time. The buildings, which were erected in the course of the factory's expansion, many of which remained unfinished, stood empty and began to decay over time. However, over the past ten years, the former industrial site has been undergoing extensive redevelopment. Ferrum 1 is the result of this redevelopment. The central design theme of the building is "rust on the outside, gold on the inside". It seems to reference the industrial and the aristocratic past of the site through contemporary materiality, namely Corten steel. While the plan of the new business centre is rectangular, the façade is more complex. The seven-storey Ferrum 1 is one of the first buildings in Russia to be constructed with a sculptural Corten steel façade. 

Corten steel is a genericised trademark term used to refer to Weathering steel, which has gained popularity as a façade material because it is resistant to corrosion and is extremely durable. Its visual characteristic which makes it appear to have a rust-red patina and velvety texture, help create a more striking visual to the architectural façade. Expressing the materiality of the surface was a central focus for TCHOBAN VOSS Architekten when they were designing the façade. The office building even gets its name from this material, Ferrum which is Latin for iron. The name serves as a dual reference as it refers to both the material composition of the façade, and the industrial history of the site on which the new building was erected.

“Wrap and weft”, the sculptural nature of the façade is constructed using a geometric grid and is meant to look like a coherent, dynamic, organically flowing fabric of loose threads. The metallic stripes span the rectangular building both horizontally and vertically. Much like the architectural fold, the design operative here exists primarily in the architectural drawing. The physical manifestations create the illusion of plaiting of the steel strips. The alternation of flat and protruding modules when viewed from the side, gives the impression of the horizontal lines diving beneath the vertical lines, and vice versa.

At the corners of the building, delicate structural glazing alternates with the sharp-edged folds of the Corten weave. This point of contact, coupled with the velvet appearance of the Corten steel, enhances the fluid form of the façade. The glass and steel seem to play around the exterior of the building. The building's main entrance is marked by a large portal, and the central foyer features double-sided structural glass that fills the space with light and visually connects it to the surrounding park. The colours of all foyers follow a two-tone concept, which actualises the theme of "gold on the inside”. The building is also topped by a band of golden aluminium panels, whose sheen visually offsets the intense colouring of the main façade cladding.

Project Details

Name of the project: Ferrum 1
Location: Saint Petersburg, Russia
Area: 7,965 sqm
Year of completion: 2021
Architect: Sergei Tchoban
Design team: Valeria Kashirina, Severin Burr, René Hoch, Natalia von Kruechten, Puk Paludan, Evgenia Sulaberidze
General contractor, Project management, Landscaping: Teorema (Business Park Polustrovo Ltd.), St. Petersburg
Structural engineering: Nord Fassade, St. Petersburg
Corten steel: SSAB, Saint Petersburg
Windows/doors: Guardian Glass, Moscow; Aluminum frames: Reynaers, Saint Petersburg; Lifts: Mac Puar S.A, Moscow; Assembly lifts: Schtihmas, Saint Petersburg