Circular construction: digital paths to a sustainable circular economy
Circular construction stands for a resource-conserving circular economy in the construction industry. Components and materials such as bricks, window glass or steel are not disposed of but reused—in line with the cradle-to-cradle principle.
The age of linear construction is over. The future lies in circular construction: Buildings are seen as material stores that can be dismantled after use and transferred to new cycles. To be successful, that requires digital tools and new planning approaches, from material databases, building information modeling (BIM) and the digital twin to the digital construction site. digitalBAU 2026 will showcase the many digital solutions for circular construction.
Every year, Earth Overshoot Day—the day on which all the natural resources that our planet can regenerate within a year are used up—moves further forward in the calendar. From then on, we live globally “on credit” and continue to work with rare earths, sand, ores, and other materials that the Earth cannot provide to the extent that we consume them. For Germany (and also Poland), Overshoot Day was already on May 3, 2025. That means that if everyone in the world would live as they do in Germany, the globally available resources would already be used up this early in the year.
Circular economy in construction: responsibility and innovation
As one of the largest consumers of raw materials, the construction industry has special responsibility in this context: The construction sector uses 90 percent of mineral raw materials while at the same time generating more than half of the total waste produced in Germany. Other impressive facts: In 2023, this resource-intensive industry accounted for around 36 percent of the EU’s total steel demand; sand is now considered the most widely used raw material in the world, with the construction sector as the main customer.
Against this backdrop, circular construction is becoming increasingly important. The aim is to conserve existing resources and reuse building product materials. Unlike the previously common linear construction method, materials should not be disposed of at the end of the building’s useful life, but be dismantled by type, recycled or reused as far as possible.
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From the cradle to the cradle instead of ending up in landfill
Circular construction, often used synonymously with the cradle-to-cradle principle, describes a continuous cycle concept. Biodegradable consumer goods are returned to natural cycles. Technical materials are broken down into their constituent parts by type and reused. Waste in the conventional sense should no longer be produced. For existing buildings, this means that they will become the material stores of the future. Every screw, every door, every piece of concrete can thus potentially be reused. Urban mining – in other words, recovering resources from existing buildings—becomes a strategic resource. Digital material registers and material passports provide the necessary transparency
Urban mining and recycling: the value of existing buildings
Urban mining is about systematically recording materials from existing buildings and preparing them for reuse. Material databases or the building resource passport document the materials used and make them recyclable and economically calculable. The systematic recording of material origin, carbon footprint, and recyclability enables a genuine circular economy in construction.
- Old rafters can be processed into squared timber for partition walls.
- Bricks can be used again directly or can be cut and used for facades and interior walls.
- Superfluous window elements are energetically upgraded and installed in new buildings.
In this way, complete buildings can be constructed with second-hand components from smart recycling. Examples of circular architecture with existing materials are the recycling house in Hannover and the recycling extension in Kelsterbach. Sustainable construction is guaranteed with solutions such as this.
Design for disassembly: holistic planning. Through to dismantling.
Circular construction starts with the design. Design for Disassembly—in other words, planning and designing for dismantling by type—becomes the central principle. Composite materials, bondings that are difficult to separate, or undocumented components make recycling difficult. Instead, the focus is on detachable, separable and documented compounds to enable subsequent upcycling or recycling.
Upcycling and reuse: creative second use of building materials
Upcycling refers to the creative reuse of materials beyond their original purpose, for example, when old gym floors are turned into furniture, or bricks from demolished buildings are used as façade material. In architecture, this results in individual solutions with a history. Here too, digital platforms help make materials available, and give planners new scope.
Serial and modular construction: models for the Circular Economy
Construction methods such as serial or modular construction offer particular advantages in a circular context. Elements that are prefabricated in the factory are easier to dismantle, sort, and reuse. Modular buildings allow flexible adjustments and more efficient use of resources. One example is the residential complex for hospital staff in Esslingen (Germany), where prefabricated modules were assembled according to the plug and play principle.
Digital tools for sustainable construction
In addition to sustainable materials and advanced construction techniques, digitalization plays a crucial role in fully exploiting the potential of the circular economy. Technologies such as building information modeling (BIM) enable a continuous flow of information across the entire life cycle of a building. They document precisely which materials were used, how they are installed, and what properties they have. This data is the basis for dismantling, reuse, and recycling.
EPDs and PCDS: the “profiles” of the products
Environmental product declarations (EPDs) are used to evaluate products according to ecological criteria. They document emissions, service life, ingredients, and environmental impact. In addition, the Product Circularity Data Sheet (PCDS) provides information on circularity, for example, whether a product can be separated, repaired, or recycled.
Material passports as digital raw material accounts
Buildings become material banks: Material passports document all the materials used, including their origin, CO₂ values and recyclability. These are stored virtually on material platforms, in the Digital Building Resource Passport from Concular or the Building Resource Passport of the DGNB (German Sustainable Building Council).
Planners and real estate or construction companies use it to record the materials and products that are processed in a building, and thus effectively pay the monetary value of the beams, doors and windows into a material account. In the meantime, a variety of applications and online platforms are available for collecting and quantifying the data, and can also be used to calculate carbon emissions and the circularity of real estate. Information on material origin and recycling is also stored in a data record.
Once the building in question has been dismantled, the materials can be recycled or returned to the material cycle in accordance with the cradle-to-cradle principle, allowing the best possible use to be made of our planet’s limited resources.
The digital twin as a tool for circularity
Circular construction and the associated circular economy of the construction industry will become an all-round success when digital planning and documentation go hand in hand with digitally controlled manufacturing and production. BIM models allow all construction-related data to be bundled in an as-built model, thus producing a digital twin of the building that is maintained and supplemented throughout the entire life cycle. This creates transparency and enables sustainable operation. Optimum preparations are also made for dismantling and recycling.
Circular economy in construction—key topic at digitalBAU 2026
digitalBAU 2026 in Cologne will show in lectures, discussion panels, and at the stands of specialized exhibitors how circular construction (as part of a circular economy) is becoming reality with digital tools. Visitors to the trade fair will experience the entire range of digital solutions and services for circular construction.
Among other things, the focus is on planning methods such as BIM, which can be used to create digital building models, the “digital twins”. By using various planning, coordination and execution tools, sources of error can already be identified and eliminated in advance. That allows the consumption of materials and raw materials to be further optimized, making a decisive contribution to the circular economy.