- Building category
- Office and Business
- Windows, Façades
- ERC 50
- Düsseldorf, Germany
- U.Sadowski, Architekt, Berlin/GER
The Hans-Böckler high-rise in Düsseldorf was built in 1968 as a reinforced concrete frame construction with precast parapets. After the interior had been renovated, the decision was made to modernize the façade, which had been designed in the typical style of the 1970s. The building had deficits, particularly regarding thermal protection during the summer. The energy consumption lagged far behind today’s standard, and the external venetian blinds on the continuous ribbon windows were no longer fully functional. The parapet elements were completely uninsulated. The U-value of the aluminum ribbon windows was approx. 3.0 W/m2K, and the G-value was around 70 %.
For the Hans-Böckler-Haus’ new façade, the architect and builder client opted for the Schüco Modernization Façade ERC 50, which was specially developed for refurbishment projects. The system is impressive due to its highly efficient energy concept, which includes double glazing and integrated solar shading, as well as the ease of installation. In the first step, the existing natural stone slabs were removed and the existing parapets, onto which the mounting brackets of the new façade were subsequently fixed, were secured. After the supports and the new window units were installed, the aluminum elements of the existing façade were dismantled step-by-step and floor-by-floor, from top to bottom. Finally, work was performed on the interior cladding, the solar shading was installed, and the natural stone slabs, which were carefully cleaned at the construction site, were reinstalled.
Apart from building maintenance purposes, the refurbishment had ambitious energy goals. The installation of the natural stone slabs – this time in front of a well dimensioned insulating plate – and the inclusion of the characteristic ribbon windows in the new design concept help to retain the architectural character of the old Hans-Böckler-Haus. The improved thermal protection and the new highly insulated aluminum profiles nearly halve the Uw-values.
The users and client drew positive conclusions. All of the goals of the façade modernization could be achieved, from the visual redesign to the significantly reduced energy consumption and clearly enhanced user comfort. The high degree of prefabrication of the façade units made it easy to plan the construction site and permitted a short construction time. The refurbishment of the Hans-Böckler-Haus’ façade, which has a total surface area of more than 5,000 m2, could be completed in a mere five months period and each employee only had to leave the office for two days.
Challenging: Logistics and construction circle
Modernising a façade while the building is in use is still something special: in general, disturbances caused by noise and dirt as well as the complexity regarding the planning process are to high. By using Schüco’s modernization façade ERC 50 it was possible to achieve all targets of the façade refurbishment – architectural improvement, energy saving optimization and higher level of user comfort – within budget and on time.
Preserving the Buildings Character
Architect U. Sadowski : "The most important aim of the modernization was to eliminate the defects of the building physics and functional shortcomings, while preserving the building's character. Not to affect the users during the modernization, was one of the basic requirements for the project."
The natural stone tiles were cleaned and lateron re-mounted. Architect Udo Sadowski and the client decided to take extensive advice on Schüco’s ERC 50 modernization façade which has been specially developed for refurbishment projects. The deciding factors were that the system, with double glazing and integrated sun shading, is on the one hand highly efficient in saving energy, and on the other hand safe to install.
After mounting the pilaster strips and the new window elements, the aluminum elements of the existing façade were removed floor by floor from the top to the bottom. First, the new elements were mounted in front of the existing spandrels then the old windows could be removed. Finally work was done on the interior finishes, the installation of sun shades and the re-mounting of the carefully cleaned natural stone tiles.
Before fixing the new façade, the existing structure was enforced. "Timing and the organization of the building site were very important in this project. All the decisions were taken in close collaboration with the client and the user. The high level of pre-fabrication of the components make site-work easy to plan and ensures a minimum construction period. The façade refurbishment of Hans-Böckler- Haus, with over 5,000 m² surface area, took just five months to complete," stresses Christian Anders, the CEO of metallbau anders, some of the advantages of the modernisation façade.
User and client alike draw positive conclusions Every objective of the refurbishment was reached. From the aesthetic re-design to the significant reduction in energy consumption and a noticeable higher level of user comfort. Cost plans and deadlines were met. A façade refurbishment that is a testimonial to everyone involved.