The circular dismantling of the Earth Sciences Building
A material world: the journey of materials through the past, present and future
Utrecht 木瓜福利影视 wants to be climate neutral by 2030. This includes a substantial reduction of our carbon footprint. When redeveloping our campus, there are therefore gains to be made. We are building future-proof and as circular as possible. But what if we have to demolish a building?
First of all, we are considering whether the building cannot be given a new purpose after all. For instance, it has already been decided to redevelop the van Willem C. van Unnik building and the Hugo R. Kruyt building. Because the concrete structures remain intact, far fewer new raw materials are needed. And that's the point. In a circular economy, there is no such thing as waste and we use raw materials over and over again. That is why we looked for the most circular way of dismantling the Earth Sciences Building and joined forces with a market player.
There is still a lot to learn in the building industry about circular dismantling and construction. This project had exactly as its goal: what can the university learn from it? And the contractor? What works well and what should be done differently next time? In this story, you will go through the past, present and future of the former Earth Sciences Building in a bird's eye view.
The past
Let's not start from the beginning...
The Earth Sciences Building was built in the early 1970s. At that time, construction was dominated by the rise of concrete. The combination of concrete and asbestos, with its flexible, rock-solid and fire-resistant properties, allowed people to build in forms they could only dream of before. Asbestos was frequently used in buildings during this period, including in the Earth Sciences Building. There, it was incorporated from head to toe: from the roofing to the sewage pipes.
Over the years, knowledge about the drawbacks of asbestos grew. The health risks are now known and asbestos is banned. As long as it is present undisturbed in a building, there is no cause for concern. But for the dismantling of the earth sciences building, asbestos was one of the big obstacles. After all, how do you ensure that as many elements as possible are reused in a high-quality manner when asbestos is present in almost all building components?
Large-scale remediation
The ambition to dismantle the building in a circular way and to reuse as much material as possible in a high-quality manner meant that almost everything in the building had to be remediated first. When the remediation started, the building was wrapped up. Culminating in a . This roof ensured not only that the remediation could be carried out safely, but also that the surrounding area was less affected by windblown dust and noise from the construction site.
A total of 211 tonnes (211,000 kilos) of asbestos-containing material was removed from the Earth Sciences Building. By cleaning cables, cable ducts and ceiling grids, among others, 22.6 tonnes of material from the Earth Sciences Building was still recycled in a high-quality manner.
In the video below, a 3D animation shows how the Earth Sciences Building was remediated and dismantled.
The present
Waste is only waste if you waste it!
After the building had been remediated from head to toe, a proper inventory could be made of which materials were eligible for high-quality reuse. Here, the materials were distinguished on three levels in the context of circularity:
- Elements: consist of one or more components/construction products. For example, the concrete parapet and the shell.
- Components/construction products: consist of one or more building materials. For example, bricks.
- Building materials: consist of one or more raw materials. Material of lowest 'value', e.g. concrete rubble.
How much was saved in each category can be seen in the overall overview of CO2 savings per element/component.
When products cannot be reused one-to-one, the product is marketed as a semi-finished product, or offered as parts. When this also fails, the product is put away as a raw material. Contractor Dusseldorp won the contract as tenderer to dismantle the Earth Sciences building in a circular way. They used the inventory app and 'materials decision tree' to make a well-supported decision to reuse all materials. Storing the released materials on site and in the building created time to look for outlets for high-quality reuse. This saved on transport costs at the same time.
The figure below explains this process of value in circularity.
The materials and products from the Earth Sciences Building mainly came out in the 'high-quality reuse' category: R3 鈥 R8.
Of all the materials from the building that could be reused, a top five was made with what saved the most CO2:
No. | What | KG CO2 |
1 | Concrete shell | 1.410.467 |
2 | Concrete parapets | 17.333 |
3 | Bricks | 8.483 |
4 | Steel beam window washing plant | 2.455 |
5 | Cable ducts | 1.428 |
A total of 1,441,956 kg of CO2 (rounded up 1,442 tonnes) was saved through the high-quality reuse of the various materials and products released during the demolition work. This 1,442 tonnes of CO2 is equivalent to driving a car with average fuel consumption for 8,363,600 km. This is 208 trips around the earth.*
*One tonne of CO2 equals 5,800 km by an average car, circumference Earth is 40,075 km.
In comparison, to offset a quantity of 1,442 tonnes of CO2, 72,100 trees are needed to absorb CO2 for a period of 1 year.*
*For every tonne of CO2, around 50 trees need to absorb CO2 for 1 year.
Materials found on campus
It's a material world
Materials from the Earth Sciences Building have been given new life at various locations at the Utrecht Science Park. For instance, wooden system walls with frosted glass from the north wing of the Earth Sciences Building will end up in the Vening Meinesz C building. And in the future, interior doors, cabinets, interiors and the wooden floor from the Earth Sciences Building will get a new use in the basement bins of the Van Unnik Building. Other furniture from the building has been put to use by the Veelzeijdig Foundation. Struikroven Foundation has repurposed the plants that were in the building.
Security cameras and paving around the building have also been reused, for example around the PNYX front door. By the way, reusing paving is a standard procedure. So this did not result in any additional carbon gain, because the calculation of the environmental cost of paving materials already assumes that they will largely be reused elsewhere at the end of life.
Finally, in the Earth Sciences Building itself, the former shaft doors were reused. They were used to close up openings (holes in the floor) as a temporary provision during dismantling. And because of this, there was no need to use new construction timber. For the material itself, it is a stay of execution, but in a sensible way.
Marketplace for building materials
The materials that could not get a second life within the university were placed on the marketplace of the foundation. Contractor Dusseldorp Infra, Sloop en Milieutechniek BV is core partner of this foundation. The aim of INSERT is to create a platform where used materials from construction and outdoor space and green objects are offered for a second life.
Through the INSERT Marketplace, we were able to sell some materials, these were all the wooden shelves of the filing cabinet, this totalled 3.2 tonnes in weight. We were also able to put away the iron beams of the glass washing plant on this platform. This was a total of 9.1 tonnes by weight. The other materials for direct reuse were taken by our regular traders, the UU and other regular partners.
The future
Surprise us!
Frame in good condition
As it turned out, the biggest environmental gain did not come from the preliminary calculations, but was discovered during dismantling. Bit by bit, the building was stripped of materials until the skeleton of the building became visible. The technical condition of this so-called shell turned out to be much better than expected. This was a huge opportunity to save a lot more CO2. By preserving only the shell, some 1.4 00 tonnes of CO2 were saved. This saving comes from no demolition, no disposal of materials, and no supply of new concrete. This saving is equivalent to about 933 years of electricity consumption (grey) by an average household in NL (average electricity consumption per household per year: 2765 kWh, source: Milieucentraal. 1800 kWh is 1 tonne of CO2). If the shell were to be demolished a new building of the same size would have to be built, this would 'cost' 2,500 tonnes of CO2. 2,500 tonnes of CO2 is comparable to the energy consumption of about 125 households over a year.
The positive environmental impact of reusing the shell is thus greater than all other actions on circularity in this project added together. The gain lies in not having to demolish and dispose of the shell's debris, and thus also in not having to supply and manufacture new materials for the future building.
Future vision
At the same time, the shell did have to fit the future vision of the plot in case of reuse. But since a building with lab and office functions, the functions that the former Earth Sciences Building also fulfilled, will come here in the future, the dimensions of the shell and the presence of technical rooms and shafts are excellent for the future.
Considerations
Because the shell already fulfilled these functions, a choice was made between two options. One: all-new so 100% to the liking and for the design, or option two: incur costs because you are working with an existing shell and therefore have to make adjustments that you would not have had to make with option one. In addition, the shape of the building allows for building one or more new floors on top of the existing building, providing the necessary flexibility for a future developer. Based on these factors, it was decided to retain the shell. This choice resulted in significant CO2 savings.
Transition building
Based on these factors, it was decided to retain the shell. This choice resulted in significant CO2 savings. The concrete framework will therefore remain and become the basis for the new 'Transition Building' that will be built around the shell. The transition building will have laboratories and offices. It will accommodate part of the research groups that are in the Hugo R. Kruyt Building. In this way, the Kruyt Building can eventually be redeveloped when it is empty.
Conclusion
In the circular decommissioning project of the Earth Sciences Building, with clear goals, an efficient contractor and lots of willpower, it has been proven that great results can be achieved. By including the ambitions of future-proof buildings in the Programme of Requirements and decisive collaboration with the contractor and partners, this project is a good example of how to dismantle buildings with asbestos in a circular way. It also shows how important it is to choose responsible materials in our real estate projects, which retain their value and can be reused in the future. We can conclude that it is an exemplary project where UU shows that we are working for a better world, also in our operations.
Lessons learned
Prior to dismantling, an inventory was made of the materials in the building, including the expected CO2 gain. During the circular dismantling process, reality sometimes proved to be more unruly than expected. What were the main learning points?
In the end, what the university learned from reusing materials (properly) is that it has to match beforehand in three areas:
- Quality: do other construction projects want to use the materials? Can reused products get the desired certificates and guarantees that new materials have? And how can attitudes towards 'second-hand' building materials be improved?
- Location: can it be dropped off nearby? If materials have to travel a long way, the CO2 savings are again negated by emissions from transport.
- Time: long storage is not always possible and costs a lot of money. How can the material get a new use quickly?
Leson 1: Supply and demand: reuse of bricks
Bricks were number one in terms of environmental gains and, in theory, they could save a lot of CO2 emissions. But in reality, things turned out to be somewhat different. Of the 500 tonnes of bricks, "only" 36 tonnes were actually reused: the equivalent of more than two trucks full of bricks. To illustrate: these 500 tonnes of bricks go on a total of 56 pallets, which hold 392 bricks. A total of 21,952 bricks were chipped clean by hand (the cement was chipped off all the bricks a chisel) for reuse. It costs extra time and money to have them cleaned, and eventually the bricks go to a company that sells them to a party that reuses them. The 36 tonnes ended up being recycled, giving it a lower R-value. This was due to several factors. The market, planning and matching supply and demand better.
Project manager Kevin Dijke: 鈥淭he tipping point has not yet been reached that reusing bricks is cheaper than new bricks. This was the reason why we were thus ultimately left with a large quantity of bricks that we could not dispose of.鈥
Leson 2: Earlier decisions: lower interior doors
Much was also learned from all the doors from the Earth Sciences Building. The hundreds of doors were qualitatively still reusable. However, the size of the door is no longer used today, as the rules for doors have changed in the building code. The project team made every effort to reuse the interior doors immediately. But as a result, these doors had to be stored for a very long time, which also costs space (and money). The learning point here is that knots have to be cut earlier and in the early stages of the process classify such a type of product lower on the R-ladder: as semi-finished products.
Lesson 3: Long-term storage: materials marketplace
The marketplace set up for this project was not always a success: the purchase of products through the marketplace sometimes lagged behind. This was because many things were outdated and no longer compliant with the current Building Decree. In the end, however, the maximum possible was achieved.
Lesson 4: Designing from supply: application on own site
In this project, use has been approached from the supply side. That is, efforts were made to find new uses for all materials. But this turns out to be very time-consuming and therefore not always successful. It is better to already discuss the possibilities for reuse for upcoming projects in the region with an architect, for example. Incidentally, internal application in other ongoing construction projects has been investigated, but was not successful because there were no concurrent projects in which these materials could be applied. An alternative is then to store the materials, but there is no place for this in the Utrecht Science Park yet. The learning point here is to look from the start of the project at where the products can end up. This is now being applied in the .