Refurbishment of Office Building Z2, Stuttgart

The six-storey office building from 2002 underwent a comprehensive energy, structural and architectural overhaul within just a few years in order to drastically reduce energy requirements and raise the working environment for around 450 employees to a new level.

ZÜBLIN made a conscious decision to renovate rather than demolish: the shell, access cores and most of the existing components were retained. The reuse of materials – including the characteristic aluminum parapet strips - and the use of recyclable components significantly reduces material consumption. Around 25 percent of the new materials used come from recycled or reusable sources.

The building's energy efficiency upgrade is a key focus: The roof, façade and underground garage ceiling have been extensively insulated. Air-to-water heat pumps now provide both heating and cooling for the building. The system is supplemented by photovoltaic systems on the roof and façade as well as an innovative PV fence, which also serves as fall protection. Surplus energy is stored in a storage system - an important basis for a particularly low primary energy requirement.

The interior of the building has also been designed with the future in mind: A modern office concept, capillary tube ceilings for heating and cooling, optimized acoustic solutions and connection to the Group's central building control system create a flexible and efficient working environment. Sustainable wood products, CO2-reduced glass and green façade segments also support the overall ecological concept.

With the refurbishment, the building has achieved DGNB platinum certification and meets the requirements of the EU taxonomy. The strategic combination of reuse, energy efficiency and digitally supported planning makes Z2 a pioneering project for sustainable construction in existing buildings - and a visible expression of the Group-wide sustainability goals.

The project is aiming for DGNB "Sustainable Building Site" certification from the German Sustainable Building Council.

Certified by the German Sustainable Building Council (DGNB)

Ed. Züblin AG is pursuing several goals with this project: A sustainable construction site organisation, the conservation of resources as well as the minimisation of emissions, responsibility for the health and well-being of the builders, the cultivation of good neighbourliness and, of course, high-quality construction. For this, Ed. Züblin AG was the first company to be recognised by the German Sustainable Building Council (DGNB).

Here you can find more information about the DGNB system for sustainable construction sites: https://www.dgnb.de/en/certification/buildings/construction-site

Selected measures in the project