STRABAG’s “tea box system” is a model for efficient, sustainable construction

Generative design is improving both innovation and sustainability in the construction industry. STRABAG’s innovative construction system can be explained using a typical household item.


Generative design supports collaboration across different departments, making planning more connected and cost-effective.

Image courtesy of STRABAG.

people collaborating using generative design at strabag

Friederike Voigt

October 25, 2022

min read
  • STRABAG is one of the 10 largest construction groups in the world.

  • The Austrian firm’s focus on innovation and digitization is combined under a separate central division unit, STRABAG Innovation & Digitalisation (SID).

  • STRABAG’s new approach is aimed at optimizing the early phases of the design and construction project lifecycle, when the largest impact on costs, deadlines, quality, and resources can be achieved.

  • Generative design provides designers at STRABAG and ZÜBLIN (the group’s German subsidiary for building construction and civil engineering) with automation tools that allow them to work in a more networked, efficient, and sustainable manner.

Konstantinos Kessoudis, head of BIM/5D Development at SID, is standing at the tea kitchen in the VR Center of the ZÜBLIN building in Stuttgart, Germany. A number of cameras hang from the ceiling, and a massive screen illuminates the room. While discussing the challenges of digitalization in the construction industry, Kessoudis takes out a compartmentalized box full of tea bags, a common household item in Austria and Germany.

“The tea box is the building,” he says. “The tea bags are the standardized components that are installed in the building.”

Kessoudis does, however, note that a tea box is less flexible than buildings. “While tea boxes are preconfigured, structures of buildings vary in size and shape,” he says. “Ideally, you’d be able to sort everything out during the design stage: organize the tea bags individually, arrange them in any box independent of structure, and network these boxes with the production system.”

STRABAG’s tea-box system uses standardized components that are connected to manufacturing processes, and Kessoudis believes that the mechanical engineers who have been working with this system since the 1990s are far more efficient than construction workers. He cites integrated factory modeling in the automotive industry as a prime example of this efficiency and says the construction sector has some catching up to do.

“This connection between planning elements and the production process is precisely what we’re missing on the building site,” Kessoudis says. But change is no longer optional for the construction sector, whose raw material procurement, building processes, and operations are responsible for almost 40% of global carbon dioxide emissions and is adopting leaner processes as a result. STRABAG’s new system is a huge step in the right direction.

Automation and networking are key to modern construction

people working in hardhats at strabag
Automation helps construction companies become more competitive and more sustainable, which is why STRABAG focuses on innovations such as augmented reality and generative design. Image courtesy of STRABAG.

Kessoudis is excited about the topics of automation and networking. “Networking reduces inefficiencies such as having to search for items on the construction site,” he says. “Automation helps us to become both more competitive and more sustainable.” He is not only talking about connecting design and construction but also about reducing the number of materials and the need for strenuous physical labor on the construction site by using robotics, 3D concrete printing, virtual-reality goggles, and artificial intelligence (AI) in the design and construction phases.

STRABAG wants to use these innovations to improve productivity in construction and is bringing partners such as Autodesk on board to achieve this goal. The cooperation between the two companies launched with a letter of intent signed by Autodesk CEO Andrew Anagnost and STRABAG Digital CEO Klemens Haselsteiner in 2020. “Autodesk is the perfect partner for us because it understands construction and manufacturing, and it can bring valuable experience from both industries to our work together,” Haselsteiner says.

Generative design optimizes the planning phase at STRABAG

different iterations of the design using generative design
Generative design can be used to create different structures. This helps land valuation planners determine how best to develop a site. Image courtesy of STRABAG.

STRABAG has had a clear focus on innovative technologies for years. Generative design is one of many innovation drivers and is now the name of a dedicated STRABAG unit that reports to Dr. Marco Xaver Bornschlegl as part of STRABAG Innovation & Digitalization. Function Lead for Generative Design Fabian Evers also mentions automation regularly. “We’re rethinking the design stage,” he says. “We’re all about automated processes. We translate expertise in architecture and construction into algorithms to automate design. Ultimately, automated design lets us optimize buildings.”

Designers used to work on a Microsoft Excel spreadsheet; now, they use an automation tool. All the designer has to do is set the parameters and define the objectives. These are then fed into a CAD system. The computer takes this as the basis for logical calculations using adaptive AI methods to create not three or four, but myriad optimal designs in a very short time. These designs also contain a far greater number of more precise metrics than any human designer could ever provide. All the designer has to do is decide on the best solution by filtering according to certain parameters.

This design method is being developed in collaboration with STRABAG Real Estate (SRE) for land valuation, for example. Project developers can rapidly determine the best way to develop a site. The tools take into account parameters such as the optimal amount of direct sunlight, the CO2 footprint, and the number of housing units right from the start.

Generative design is also used in detailed planning. It “greatly simplifies the designers’ work,” Evers says. His team has programmed standardized staircase and elevator modules that are automatically generated in Autodesk Revit once parameters such as the floor height are entered. This means that the designers do not have to redraw standard staircases every time they start a new construction project; instead, they can refer to the blueprint. This is a prime example of the “standardized tea bag.”

“The computer-generated stair module saves us a lot of time at the design stage,” Evers says. “Instead of three weeks of fiddling about, the design for a staircase can be completed in a single day.” Designers no longer have to bother with modeling simple components. A variety of floor plans make it much easier to move walls, as the modules automatically adapt to changes to the model. This saves valuable time in responding to individual customer requests.

In the future, STRABAG and ZÜBLIN want to develop parts of buildings or even entire buildings as a “tea box” construction system based on the staircase model. The planning, production, and final assembly of these structures on the construction site will all be automated. All three stages will be seamless, digitized, and networked.

Algorithms connect planners

people in hardhats in a tunnel
Automation tools allow employees at STRABAG and ZÜBLIN to work in a more networked, efficient, and sustainable manner. Image courtesy of STRABAG.

This method of working enables closer collaboration between designers who previously worked in silos. It brings architects, structural engineers, building services engineers, sustainability experts, fire protection officers, facade planners, and structural engineers to the same table; gives them a better understanding of interdependencies; and allows them to see the building as a whole. In short, generative design makes planning more networked.

One of the main benefits of this for the construction industry is sustainability. This new digital design method gives sustainability experts (who have traditionally had a say only at the end of the planning phase) a voice right from the start, as the tool takes the carbon footprint into account from the very beginning of a project.

“This is a huge help in the move toward sustainable construction,” Evers says. He explains that design decisions are now based on facts and parameters whereas they used to be based exclusively on the experience of experts. Without the aid of generative design, a vinyl window would be installed in a certain way because “that’s the way it’s always been done” and it’s more economical in the short term. Now, however, the automation tool will suggest an aluminum window because it lasts longer and is more sustainable.

STRABAG believes that automation tools and generative design can revolutionize the planning and construction process. They accelerate pipelines; bring experts together; and save time, money, and resources. Optimization is the magic word, automation is the magic wand, and the tea box is the hat from which designers conjure up standardized components for production.

Friederike Voigt

About Friederike Voigt

Friederike Voigt is Content Manager for Autodesk being responsible for Design & Make with Autodesk in EMEA. She previously worked as a journalist with Callwey, a German leading publishing house specializing in architecture. While studying Media Management and History of Art she was awarded a national scholarship in journalism and worked for various newspapers and magazines including the German Press Agency (dpa) and Cicero Magazine.

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