Impressive timber hybrid building is sustainable flagship project
For EDGE Suedkreuz Berlin wood and concrete prove to be an unbeatable team when it comes to ecological construction. The office building planned by Tchoban Voss Architects at Schöneberger Linse with glassfibre reinforced concrete panels by Rieder is in many respects a showcase for the change that is taking place when it comes to standards for new buildings.
A look behind the concrete skin facade of the project reveals that a new age for real estate development is finally upon us. Germany’s largest timber hybrid building shows how the needs of sustainable construction can be combined with many other requirements of a building with 32,000 square metres of floor space. Tchoban Voss Architects and the visionary project developers EDGE used concrete skin glassfibre reinforced concrete panels for the facade of this imposing wood structure in Berlin. The high-performance elements with a thickness of only 13 mm complement the well thought-out concept not just in terms of design. The requirements for the products used in this DGNB Platinum pre-certified project are particularly high. The Rieder product impressed with its visual appeal and design options as well as with technical aspects such as its comparatively low weight and high environmental and health standards.
Visionary wood and concrete
The concrete skin elements are an important part of the DGNB Platinum certificate of this flagship project in Berlin. The building material wood and the concrete elements by Rieder not only complement each other architecturally, they also advance the same goals regarding ecological construction and reduction of CO2 emissions. Rieder consistently meets the highest environmental and health standards. All products have always been free of crystalline silica. “Rieder approaches production with much energy and ecological awareness. This is also very important for the project developers, because EDGE of course is looking for the building to be a role model in terms of eco-friendliness, ecological construction and ecological materials,” says Sergei Tchoban, underlining Rieder’s commitment to better architecture.
Rieder’s goal is not only to prepare for the future of the company, but also to ensure the preservation of our world for future generations; Rieder thus takes comprehensive steps to prepare its glassfibre reinforced concrete facade products and company operations for the future. The main focus for Rieder is to make its products and operations more ecological. “Our central goal is to be CO2-neutral by 2025. We want to have a positive CO2 balance by 2030. To this end, the company is currently working on the development of a cement-reduced and subsequently cement-free concrete, among other things,” says Wolfgang Rieder. In a first step, 50 percent will be substituted, which saves 30 percent in CO2 emissions. This makes Rieder the first facade manufacturer to produce CO2-reduced glassfibre reinforced concrete. In spring 2022, the result will be seen in textured slate in a limited colour collection on the facade of the new glemm21 headquarters.
Concrete on wood: opposites or the new normal?
You cannot see the exciting inner life of this visionary building at first glance. Above ground, the building extends over seven floors. Hundreds of wall elements (including windows) and over a thousand ceiling elements were manufactured in wood-concrete construction. Wall and ceiling modules were prefabricated at the factory. They were delivered to the construction site as required, where they simply had to be joined together. This saves plenty of time and storage space on site.
A number of additional key advantages made Rieder the right partner in this particular case. The comparatively low weight of the facade panels was a particular advantage: “Not everything can be attached to the wall elements of the wood hybrid system: natural stone, for example, would be far too heavy. It would weigh almost 100 kilos per square metre. One element from Rieder is three times lighter!”, explains architect Sergei Tchoban. In addition to the standard size of the glassfibre reinforced concrete panels, project-specific sizes can be produced easily. The material also guarantees absolute safety and fire resistance due to its excellent thermal properties and is assigned to fire protection class A1 “non-combustible” according to DIN 4102. This means there is no need for a sprinkler system for the facade. Pre-assembly in the factory, independent of weather conditions, guarantees a high quality standard, an efficient and flexible construction process, and rapid assembly on site. The prefabricated modules are simply hooked in on site and tweaked into place.
Three different colours were used for the building envelope: sahara, a sandy shade, which makes visual reference to the wood that dominates the interior. The pylons divide the facade vertically. They were accentuated with the colour terracotta, and their reveals visually set off in silvergrey. To ensure that the individual components interact perfectly, Rieder and the architects constructed a 2.50 metre high facade mockup, which allowed all details and joints to be checked again.
A carré and another, smaller building make up this urban complex with its rhythmic facades defined by the fine structure and the discreet colours of the concrete skin elements by Rieder. “We are impressed with the feel and the surface of the concrete panels, which have a thickness of only 13 mm – and with the product’s natural appearance,” says Sergei Tchoban, explaining the decision. Glassfibre reinforced concrete from Rieder consists of raw materials taken from nature, which produce a special surface appearance that is characteristic of concrete. The sustainable and weather-resistant panels have a long service life and offer a wide range of facade design options.