The circular economy is based on the three principles of the Ellen MacArthur Foundation, which can be implemented as follows:

1. Value finite resources and control their stocks and material flows. Dematerialise value, use renewable raw materials, replace finite resources and recover used resources
2. Improve raw material yields by closing loops while always maintaining the highest possible value of the raw materials. Close loops, share benefits, 'use rather than own', extend lifetime, repair products, reuse, refurbish, recycle materials, avoid waste
3. Ensure the effectiveness of the system through consistent consideration of externalities. Consistently include external consequences for humans (e.g. health, justice) and the environment (e.g. pollutants, emissions).

The DGNB builds on this definition of the circular economy and wishes to contribute to a far-reaching consensus and to the dissemination of this basic under¬standing.

The Circular Economy is logical – but how can the transformation succeed?

The globally widespread linear economic system is based on a life on credit. It rests upon the use of finite resources and leads to the growing scarcity of resources through increasing consumption and population growth, with environmental problems getting worse and global injustice increasing drastically.

Instead of extracting resources regardless of their finiteness as before and disposing of them again after a short period of use, we should focus on preserving quality and on the resulting possible circulation between the phases of production and use.

In view of the fact that globally available resources are finite, it is becoming increasingly important to keep the raw materials once taken from the planet in a high-quality condition and to use them as long as possible. Nevertheless, more and more new resources are introduced into new buildings and consumer goods, where they usually remain in or are "stored" in for many decades. Instead of disposing of these at the end of life, the building stock and also the goods produced by man are increasingly being considered as a central source of raw materials. In this context one speaks of "urban mining" or of the anthropogenic (i.e. man-made) stock.

Over the course of half a year, the DGNB held a series of workshops on the subject of "circular economy" together with experts from the construction and real estate sector as well as from the waste management sector. The following workshops took place in 2018:

"Circular Economy – Shared Spaces"
"Circular Economy – Construction level/building structure"
"Circular Economy – Deconstruction"

The results gathered in the workshops have been published in the report "Circular Economy - Closing loops means being fit for the future".

Circular Economy within the DGNB System

The responsible use of resources has been a central concern of the DGNB from the outset. For this reason, the DGNB has anchored in its certification system and thus in the market a large number of aspects that contribute to a circular economy in the construction and real estate sector. These are for instance the building life cycle assessment, the conscious choice of construction products with regard to their composition and origin, as well as the ease of recovery and recycling.

Furthermore, circular economy bonuses were introduced with the 2018 version of the DGNB system, allowing for the first time to make concrete, progressive solutions for promoting circular economy at the building level assessable and measurable within the framework of certification. By awarding bonus points, which have a positive effect on the certification result, incentives and experimental spaces are created to develop new solutions and promote innovation. As part of the revision of the DGNB system for districts, these bonuses will also be transferred to the district level and further developed accordingly.

After all, sustainable construction can only succeed if everyone fulfils his or her responsibilities and uses the corresponding potential. This is the only way that individual measures can result in an improved, larger whole - every contribution is important and counts!

Design for conversion and deconstruction

The reuse of building materials and components as well as their material recovery offer great potential in all three pillars of sustainability. A detailed overview of these can be found in the Circular Economy Report (order here).

Reuse

In practice, implementation of reuse usually fails because of the inner attitude of the stakeholders involved in the construction process and of the building users, since components that have already been used are often automatically associated with a lower quality. Other obstacles are, on the one hand, the existing uncertainty and unawareness with respect to the legal situation regarding the reuse of used components and building materials. On the other hand, existing processes are often not yet economically viable and therefore not yet scalable. In addition, there is an availability problem today: the corresponding materials or products are not always available in the required quantities with the same quality levels.

For reuse, three concrete fields of action can be identified:

• Take a stance for circular economy
• Improve the legal situation
• Optimise processes

The respective challenges as well as the resulting tasks and necessary steps for the stakeholders involved in the construction process are described here.

Strategic fields of action

Material recovery

If a building loses its original function, it is deconstructed. If a possible reuse of the components/partial components/construction products has been excluded, the material recovery represents a possible scenario. In order to enable later use or recycling, construction and demolition waste must be collected and transported separately in accordance with the Commercial Waste Ordinance.
Four specific fields of action can be identified for material recovery:

• Optimise deconstruction practice
• Assume product stewardship and establish take-back concepts
• Increase recycling rates and their demand
• Avoid hazardous substances and pollutants and demand documentation

The respective challenges as well as resulting tasks and necessary steps for the stakeholders involved in the construction process are described here.

Strategic fields of action

Multi-use of areas

Like many other Circular Economy approaches, dividing areas is not a new idea, but is already accepted and widespread in many areas of everyday life. The motivation for multiple use can arise, for example, for reasons of efficiency, for example when common infrastructure and supply areas such as kitchens or sanitary facilities only have to be created once and care and maintenance can be divided among the users. However, social aspects can also play a role if social contacts are established through the joint use of areas, if the neighbourhood is revitalised by longer periods of use and greater diversity, and if there is a stronger exchange with the social environment.

The DGNB has promoted the multi-use of areas in its certification system right from the start. Measures to increase the accessibility of buildings (e.g. publicly usable open-air facilities at the building, publicly accessible catering facilities or the letting of premises to third parties) and to increase the variety of uses ensure that the daily useful life of the building is extended and that more people can participate in the use of the building. This in turn promotes user identification with the neighbourhood and the built environment. The 2018 version of the DGNB system also rewards the multi-use of areas with two circular economy bonuses.

What are the central challenges and requirements for the multi-use of areas? The following fields of action can be derived:

• Take a stance for circular economy
• Improve the legal situation
• Optimise processes

Strategic fields of action

Here you can find checklists for download with relevant questions which building owners and planners should consider in the course of the entire planning process with regard to conversion and deconstruction as well as multi-use of areas. 

Checklist: Conversion and deconstruction-friendly planning

Checklist: Multi-use of areas

Please find in the following exemplary projects that have implemented the concept of a circular.

	Rathaus Korbach Dismantling of the town hall structure from 1970 which was not worth refurbishing, and construction of a new building on the same location. Selective dismantling with subsequent local recycling of the mineral waste materials. Completion is scheduled for the year 2021.
	Reallabor Space Sharing Stuttgart With "Reallabor Space Sharing", practical aspects of new models of space utilisation and making use more intensive through multi-use are being researched and tested. The project by the Staatlichen Akademie der Bildenden Künste Stuttgart, project managed by Prof. Matthias Rudolph, started in 2015, is a research proposal supported by the "Ministry for knowledge, research and art Baden-Württemberg" as part of the regional programme "Strengthening the contribution of science to sustainable development".
	Urban Mining & Recycling (UMAR) Experimental unit within the NEST research building of Empa (Dübendorf, CH) suitable for the circular economy Application of only pure sorted, pollutant-free and fully reusable and recyclable or composting materials. Materials will be routed back to their biological and technical cycles after dismantling (planned for 2023).

Further examples are to be presented here in the future. For the presentation of your project, please contact Christine Ruiz.

Martin Pauli, Arup Deutschland GmbH (only in german)

Tina Snedker Kristensen, Troldtekt A/S (only in german)

Alexander Geißels, SAINT-GOBAIN ISOVER G+H AG (only in german)

Teodor Tudorica von CRAFTWAND