The learning process of circular dismantling of the Earth Sciences building

The Earth Sciences building is being dismantled. Although the building was not built to be dismantled and contains a lot of asbestos, we are trying to make the dismantling process as circular as possible. The purpose of circular dismantling is to prevent waste. This means that the materials released from the building are reused as much as possible into new products, materials and raw materials of the same quality and nature. The circular economy is designed to maximise the reusability of products and raw materials and minimise value destruction.

Utrecht University considers it its responsibility to contribute to shaping a sustainable society and has defined circular objectives for the organisation in the Strategic Sustainability Plan and ambition document for Future-proof Buildings. KPIs have been drawn up for new buildings and redevelopment projects so that buildings are designed and realised in a circular manner as possible. For the demolition of old buildings, such as the Earth Sciences building, the aim is to give as many materials as possible a high-quality new use. Another goal is to learn as much as possible about circular dismantling. In this project, the circular ambitions were explicitly translated in the tender documents, such as the contract award guidelines and the specifications, during the project preparation. The contractor Dusseldorp Infra, Sloop en Milieutechniek was selected on this basis.

How is the building dismantled in a circular way?

Almost everything in the building is of value and the aim is to reuse as many products released from the building as possible on a one-to-one basis. Before dismantling started, an inventory was made of all the materials present. To determine the method of reuse, the decision tree of Cirkelstad, made by SGS Search Ingenieursbureau, has been used. This decision tree has been digitised and integrated into the demolition process. With this tool, the R on the Ladder van Lansink is digitally determined. This shows the reuse scenario of the material and it can be put on the market. If it later transpires that the scenario has changed, for example from reuse to recycling, this must be substantiated and recorded. In this document is explained how the CO2 reduction potential is calculated. 

This decision-making process is aimed at extending the life span and ensures that the products are moved to the next life cycle in the highest possible quality. The chain below explains this process of value in circularity.

Most products released from the Earth Sciences building fall into the category of repurpose and recycle. 

Mobile weighing stations

During the preparation, a materials list was drawn up of all the materials in the building. A weight has been assigned to these materials. This means we know what the building "weighs". Normally, the contractor transports the materials to authorised processors, whereby the trucks are weighed. But in this dismantling, many materials are sold directly to the new users. To verify this part of the reuse process as well, we work on site with mobile digital weighing stations. In this way, everything that leaves the building is weighed and the reuse is mapped at the same time. This process is 100% verifiable.

Tracking the circular status

During dismantling, the circular status of the project is monitored. The use of a dashboard provides insight into the status of the project. In this way, the contractor and the university can jointly examine whether the reuse percentage can be further increased. The data generated during the dismantling provides a practical basis for making the right material choices for the buildings of the future. An excellent step in the direction of circular construction.

Marketplace for reuse of materials

The released materials are placed on the Insert market place. Contractor Dusseldorp is co-founder and core partner of this foundation. The objective of Insert is to achieve a better and healthier world, now and for future generations, through cooperation. This fits well with the goals of Utrecht University.

Which materials are released for reuse?

In order to determine how the elements of the Earth Science building can be reused in the most optimal way (from a quantity and possible environmental benefit point of view), a top 10 of the most promising and impacting released building products has been determined.

The top 10, as currently determined, is as follows: 

1. Bricks outside
2. Bricks indoors
3. Precast concrete parapets (the part of the wall between the floor and the bottom of the window frame)
4. Prefabricated concrete stairs
5. Steel structure
6. System ceilings
7. Aluminum exterior frames (if sold within the UU, otherwise it will be recycled at a high rate)
8. Cable ducts
9. Flat glass (window glass)
10. Interior frames

For this project, the consequences of reuse at element level are calculated in comparison to a standard approach, which usually involves recycling scenarios.

What do we learn from the circular dismantling process?

The process of calculation and consideration is in full swing throughout the project and is not yet a calibrated process. For example, the contractor makes overviews and choice matrices that are supplemented while the project is running. The costs and revenues and any consequences for the planning and lead times are also identified.

In addition, the sale of the materials is thoroughly investigated. In the first instance, we try to do this within Utrecht University itself, but this is not always feasible because projects do not always match up. Also, some materials are outdated in terms of dimensions and material type or no longer comply with the rules of the Bouwbesluit (this is a collection of technical and other regulations that apply to the building, state and use of a building). For example, all the doors in the Earth Sciences building cannot be replaced because they have dimensions dating back to the 1970s. In this era, asbestos was also widely used, which we now know is less safe than we thought at the time. Many materials have been affected by this and are therefore reduced or unusable.

It has long been said that circular dismantling is not possible in the traditional real estate sector. With this project, we are investigating what is possible. Although there are many unforeseen circumstances on the road to circular dismantling, we are gradually learning more about the process. We carefully record everything we learn and want to share this knowledge. That way we can learn from each other and further optimise the circular dismantling process.