Circular Economy, General
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Closing the gap: the DGNB certificate for the deconstruction of buildings

Circular Economy or Cradle to Cradle is often talked about when it comes to planning buildings or developing products. The question the logistics and processes at the end of use is hardly ever discussed. But if we do not make deconstruction sustainable and do not close cycles of materials at this point, many problems will remain unsolved. The DGNB would like to change this!

If graphic designers are to visualise sustainable processes, they often choose a circular or infinite shape. After all, processes should not be broken off, but rather renew themselves. The life cycle of a building is one of such processes. However, currently this is more wishful thinking than reality in the building sector.

In other words, we have to look at today’s deconstruction practice if we are to take recyclable construction in the building sector seriously. Dismantling which is planned and implemented today according to sustainability aspects offers the opportunity to hinder the raw materials from being wasted at the end of the building’s life, but to reintroduce them into the cycle by reuse or by carefully separating and recycling the materials accordingly. And: In this way, CO2 emissions can be saved significantly.

Over the past 12 months, the DGNB, together with experts, has defined relevant aspects in a building deconstruction certificate.

Fig. 1: The life phases of construction projects – the end of life has long received too little attention. © DGNB

Sustainable deconstruction in twelve criteria

For the conception of the new certification, the focus was on strengthening recycling management and closing material loops in today’s deconstruction practice. For this, the optimisation of processes is elementary, because the interaction of different aspects and actors is always important in order to implement holistic sustainability.

The principles that make up sustainable dismantling were derived from:

  • Identifying hazardous substances
  • Optimising recycling and disposal
  • Improving and expanding processes
  • Putting people in focus
  • Creating transparency

Fig.2: The basic motives of the deconstruction certificate are reflected in various criteria. © DGNB

These objectives have been translated into twelve criteria which address the five topics of environment, economy, socio-cultural and functional aspects, technology and processes.

Making Circular Economy transparent and measurable

The concept of a Circular Economy has been a matter close to the DGNB’s heart since it was founded in 2007 and has always been anchored in the criteria for new construction certification in different aspects. It was therefore a logical step to make the deconstruction of a building transparent and measurable by means of a certificate when considering the entire use of a building. After all, the necessary transformation towards a true recycling economy requires fundamental innovations and multi-layered changes. On the one hand there are technical challenges, but also a lack of knowledge.

How are buildings deconstructed nowadays and how must our buildings be planned today so that the further and re-use of the materials and components used really works? Because with “better screwed than glued” or other blanket considerations, we are falling short, i.e. we have to understand how processes can be optimised and planned today, and where we urgently need innovations. On the other hand, there is a lack of legal regulations or the regulations existing are not coordinated and then still lie in different areas of responsibility. For example: waste law has nothing to do with building law. So how can such a complex objective be promoted?

In order to remedy this situation and to enable cooperation (even without appropriate fiscal policy standardisation), a certificate is important in order to strengthen various areas in terms of the circular economy, but above all to establish standards in the market that are higher than the current legal requirements. This will allow us to act more quickly, to try things out but also to provide positive examples to political decision-makers in order to ambitiously develop the minimum legal requirements further. The DGNB certificate is therefore dedicated to dismantling planning, material flow balances, recycling and disposal, separation of pure materials/ recycling management and hazardous substance remediation.

An example: If a building is deconstructed, demolition masses are generated – which consist of the sum of the materials the building. In order to make the treatment of these substances assessable, the certificate first asks which materials are generated. Then the further transport is considered, i.e. where are the demolition materials transported to. Further questions are resolved: what happens to the materials? Can they be reused via component storage, can they be recycled or do they need disposing?

Fig. 3: Instead of simply mining resources, the focus should be on maintaining quality and thus enabling the recycling of materials. © DGNB

In this way, an honest material flow balance can be drawn up. This brings transparency to the extent of how the entire process pays off for the concept of the circular economy and climate friendliness. The better the balance sheet, the more points are awarded. This transparency also makes it clear where the potential for improvement and optimisation lies in order to achieve a better result in the future projects.

Who can benefit?

The certificate offers different advantages for different groups of stakeholders. It offers local authorities quality assurance and success control. For people living close by, it ensures that residents are exposed to as little noise, dust, pollutants or construction site traffic as possible. The application of the new certificate also has advantages for owners and developers of projects. It contributes to cost security and risk minimisation – an important point, as the responsibility for construction supervision and coordination as well as the associated liability lies with the building owner.

However, for all those involved, it provides the very important impulse to fundamentally question the demolition measure, because the DGNB certificate for the deconstruction of buildings rewards the preservation of the building fabric. The deconstruction of buildings should always be the last option, because the preservation of building fabric is one of the most important levers for consistent climate action and resource protection. CO2 emissions for producing new materials can be avoided and also from the entire demolition and construction process. In addition, waste quantities can be reduced.

Demolition and recycling companies can position themselves through the certificate: Circular Economy is important for protecting the climate and future topic, including for optimising processes.

So, what happens next?

Following the designing of the certificate by independent experts and players in the construction and dismantling industry, we have now declared the initial application phase. This means that the market application can begin immediately, but also the test for the criteria and topics: Where do dismantling practices stand today? Where can we tighten the requirements and where are they too ambitious? And above all: How quickly do the stakeholders understand the topic in order to initiate a broad transformation? Answering these questions not only helps to optimise and further develop the criteria of the deconstruction certificate through the applications, but also to gather the necessary knowledge, which then flows into the further development of the DGNB new building certificates and the DGNB academy courses.

And thus – the circle is complete.

Would you like to get to know the criteria in detail? You can find out more about the DGNB system for the deconstruction of buildings on our homepage.

Filed under: Circular Economy, General

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Dr. Christine Lemaitre was born in Gießen, Germany in 1975 and studied structural engineering at the University of Stuttgart from 1995 to 2000. After working in the USA for two years as structural engineer, she started in 2003 working at the Institute of Lightweight Structures Design and Construction at the University of Stuttgart as a research and teaching assistant. In 2007, she started as a project manager for R&D at Bilfinger Berger AG in the area of resource efficient buildings. She completed her phd thesis on adaptive lightweight structures in 2008. In January 2009 she took on the role as director certification system of the German Sustainable Building Council. Since February 2010 Dr. Christine Lemaitre is the CEO of the German Sustainable Building Council. Since 2013 she is member of the board of directors of the Sustainable Building Alliance. From 2015 until June 2019 she was Chair of the European Regional Network (ERN) of the World Green Building Council. Since 2016 she is board member of the World Green Building Council (WGBC).

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