With the complete renovation of its Z2 corporate building in Stuttgart, Ed. Züblin AG is sending a clear message about sustainable construction. In the space of just 18 months, the six-storey office building underwent a comprehensive, energy-efficient refurbishment and an architectural reinterpretation using a BIPV façade and Cradle to Cradle certified systems from Schüco.
| Type of Building | Office and administration |
| Product areas | Windows Facades BIPV |
| Schüco Systems | AWS 65 FWS 50 BIPV |
| Features | Refurbishment Decarbonization Energy efficiency Cradle-to-Cradle |
| Location | Stuttgart Degerloch, Baden-Württemberg |
| Completion | 2024 |
| Architects | Ed. Züblin AG |
| Specialist company | Forster Fassadentechnik GmbH,Schwend Metallbau |
| Picture credits | © Achim Birnbaum Teutonenstraße 4 70771 Leinfelden-Echterdingen |
Instead of demolishing the Z2 building which was built in 2002, the decision was made to further develop it. The building shell, stairwells and sanitary facilities were preserved, while the façade and interior were completely renovated using reused or recycled materials. Supplemented with Cradle to Cradle building materials, the end product is a prime example of sustainable construction for existing buildings. The basis for the project was the digital design process using generative design. The building was captured parametrically to simulate hundreds of options for façade construction, use of natural light, air volume and heating and cooling loads. The result is a building that has been optimised for energy efficiency while also preserving the character of the ZÜBLIN Campus.
As an architectural principle, the incorporation of building-integrated photovoltaics was part of the renovation strategy right from the very beginning. The anthracite-coloured BIPV modules give the building its characteristic appearance and influence the energy balance of Z2. With a standard grid size of 1.35 x 0.9 metres, they harmoniously structure the façade and take on a safety barrier function in the fascia area as a “PV fence”. The system comprises a total of around 350 façade modules with an output of 107 kWp and a PV fence with an output of 29.1 kWp. Due to the irregular geometry and shading of the building, the layout was adjusted for the specific property. The uneven geometry of flat, concave and convex façade sections posed a particular challenge during planning and fabrication. While it was possible to fabricate the convex modules using heat at the factory, the concave elements had to be cold-fitted into the frames on site while under tension. This allowed the curvature of the façade to be precisely mapped out.
In addition to the energy-efficient refurbishment, Z2 was transformed into a modern working environment with flexible room structures and digitally controlled building technology. Digital cycle control helped to optimise building processes and enabled the precise coordination of all trades. For the first time in the interior construction industry, a mobile 3D concrete printer was used. This further accelerated construction progress and allowed materials to be used in a targeted way. The renovated building meets the EH 40+ NH Efficiency House energy standard and has been awarded DGNB Platinum and QNG Premium certifications.
