A comprehensive redevelopment of a complex of two 19th-century townhouses rising above Wiosny Ludów Square in Poznań has just been completed. Both buildings, which are part of an investment called Kamienica Wiedeńska (Vienna Tenement House), stand in a very prominent place – at the junction of Szkolna and Podgórna streets. According to representatives of the Demiurg studio, which was the author of the replacement designs and the general contractor for the works, this realisation was one of the most demanding challenges carried out in the city centre.
The Vienna House – from demolition to precise reconstruction
When work began on the project, both properties were in a very poor state of repair, so the reconstruction had to start with demolition. The buildings used to tower over Podgórna Street and partly over Wiosny Ludów Square, which was one of the most representative places in pre-war Poznań. At the beginning of 1945, the tenements were damaged, after which they were rebuilt in a simplified form. After years of neglect, they were in a poor condition, so as a result of expert assessments it was decided to demolish them almost completely, keeping the front elevations. Work began with the removal of the outbuildings, ceilings and internal walls. Subsequently, supportive foundations set on micropiles were constructed, which were used to install a structure to protect the façade. It took nearly a year to set up the steel truss weighing nearly 90 tonnes.
Construction in the former moat area and logistics
Due to the location of the townhouses in the area of the former city moat, the entire building had to be founded on piles. In order to protect it from groundwater, a white tub-type waterproof structure was used here. Only after the ceilings were in place could the substructure be dismantled and further work begin. These, however, were not any easier. The narrow space of the construction site, the constraints of tram traffic and the proximity of other projects required particular coordination. All deliveries had to be planned very carefully, and any delay risked bringing the work to a halt. Strict discipline, schedule control and precise management ensured the success of the project.
The Vienna House – with respect for heritage
The project was carried out in close cooperation with the City Conservator of Monuments. In order to meet modern energy standards without interfering with the historic façade, thermal rendering was used on the inside of the buildings. Reinforced acoustic insulation was also provided in the vicinity of the track. The façade of the corner building and the neighbouring building was reconstructed on the basis of archive photos and surviving documentation. The old proportions of the windows were restored, the corner oriel topped with a cupola was reconstructed, the balconies were reconstructed and care was taken to preserve the historical details. Today, the Vienna House serves as a residential, office and service building. In addition, it has been fitted with modern utility systems that do not interfere with its historic character. A glazed terrace has been added to the rear section, which introduces a new quality of space without compromising the historic form of the building.
New life for Poznań’s historic buildings
Contemporary architecture is increasingly abandoning greenfield construction in favour of the renovation of existing buildings. This approach requires a great deal of experience, technical knowledge and the ability to conduct a dialogue with the past. The Poznan-based company Demiurg has specialised in this type of project for years. Their realisations show that it is possible to create architecture that does not impose new forms, but brings out the potential in existing buildings. The renovation of the Vienna Tenement proves that even buildings in a very poor technical condition can be brought back to life. Here, the key to success was close cooperation between the contractor, investor and conservator, and consistent attention to quality.
Investor: DS New Venture
Construction project: SPA Design Office
Replacement building design, detailed designs: DEMIURG
General contractor: DEMIURG
Photographs: Maciej Lulko
Read also: Poznan | Tenement | Architecture in Poland | Metamorphosis | History | Monument | Renovation
Viennese tenement house past and present
