Interviews - Recreate

August 20, 2024

In this interview, we speak with Kjartan Gudmundsson, an associate professor and leader of WP3 in the ReCreate project, focusing on digital supply chain management and information sharing. WP3 is dedicated to advancing the project’s digital infrastructure, including creating digital models of individual concrete elements. Our discussion will explore how these innovations streamline supply chain processes and enhance data transparency. Join us to gain insights into the cutting-edge digital strategies driving efficiency and sustainability in construction.

Hello Kjartan and thank you for doing this interview! Can you introduce yourself and tell us about your background and role in your institution and the project?

K: My name is Kjartan Gudmundsson. I’m associate profesor at KTH in Stockholm and I’m a leader of work package 3. I’m thrilled to be a part of the project. It’s nice to be a part of something that can promote the reuse of concrete and, eventually, building materials in general.

Can you provide an overview of the progress made in Work Package 3 (WP3) of the ReCreate project so far, and what are the key achievements in the development of data-sharing protocols and digital representations of construction elements?

K: We know how different actors (different specialists in the industry, different stakeholders and actually anyone interested) can capture and share data in a common data environment in a manner that enables other actors in the reuse process to find the information needed to support effective reuse of prefabricated concrete elements. This can support good decision-making, from the early state of doing the inventory of buildings throughout the pre-demolition audit to quality control and towards marketing or the delivery of information needed for a marketplace. This is based on knowing how to name things and how to organize data, how to integrate data and how to make an automated retrieval of the information needed in the reuse process.

We also know how digital tags can be used to track and trace the physical location of physical elements and how the tags can be used to link the physical element to its digital twin and the information linked to the digital twin.

We are in the process of taking inventory of available methods for the reconditioning of concrete elements and how to comply with health, safety, and environmental regulations.

How does WP3 contribute to the broader goals of the ReCreate project in terms of sustainability and resource efficiency?

K: Digital methods for sharing data throughout the value chain will support cooperation of different actors and support decision-making and communication with stakeholders in general and therefore facilitate sustainable and effective use of resources. Having demonstrated this in a realistic process will help illustrate it to the industry in a way that can promote further development.

The common data environment is the infrastructure making this possible while the digital tagging of the building elements makes it easier to follow the elements throughout the supply chain while the tags also make it possible to link the successively collected data to the digital model. We will also be looking at the physical processes of reconditioning the elements. Practical examples of use and full-scale testing and the involvement of industrial actors will of course strengthen the value of this contribution.

Could you explain the role of Radio Frequency Identification (RFID) technology in WP3 and how it is used to facilitate digital supply chain management and information sharing in the project?

K: We have already done a comprehensive study that shows how RFID technology as well as a number of other technologies make it possible to tag the physical elements so that we can see the location and movements of the buildings elements. One actor puts a tag on the element, the elements travel to the next place and movements are registered. Any actor with access can then read off that information.

As I said the tags can also be used to pair the building elements to their digital representatives so that the tag can be used to access a digital inventory containing information about the elements such as historical information, results from pre-demolition audit, results from quality tests and finally a material passport containing the information needed for effective reuse.

Can you share some insights into the development of a common data environment (CDE) for storing BIM data and digitized information? What challenges were encountered in creating this central repository?

K: Our work provides an overview of available solutions for Common Data Environments (CDEs) that can enable effective storing and sharing of data that is captured and created. We have also discussed how data and files can be named and stored in a manner that enables automated retrieval of files and information. The basic principle is that knowing the naming principles for files and how the data is organized in those files will give the user the possibility to search for and collect the information needed. An important feature is that we want to be able to control the access and authorisation to the different files and documents while this access can also depend on the stage of the process, from work in progress to the sharing of data across teams to published files and archived material.

This includes the use of the current platform for sharing information in the research project. We look forward to further development of digital protocols for capturing and sharing data that will support decision making throughout the reuse process, such as historical information, data from pre-demolition audit and quality assurance to give just a few examples.

Interoperability or the ability of different software to exchange data is a big issue and to some extent a challenge. In a way, there is a trade-off between using open platforms and their application programming interfaces (APIs) that allow for customisation of functionalities and the using of more well-developed software platforms.

WP3 involves creating digital models of individual elements. Could you elaborate on the process of generating these digital models, including the use of Industry Foundation Class (IFC) as an open file format?

K: The digital elements are generally created using well-known proprietary design authoring tools for 3D modelling. The main process is to create those elements with data from existing drawings. The purpose of using the IFC open file format is to make the models accessible across different software platforms. Another reason is that the IFC files have a well-defined data structure or schemas that makes them less sensitive to the software versions used. You can in fact read the files with a number of freely available IFC viewing tools and even read them with just a few lines of own computer code.

How does WP3 ensure that the information collected from the digitalization of elements is used effectively, especially in supporting the needs of designers as mentioned in WP5?

K: By having a well-defined definition of the data needed throughout the process from quality control to design we can make sure that the digital elements either have the information needed or at least a place to store that information or a link to it when it has been collected. Firstly, we have to know what is the data needed. Secondly, we have to know how to make that data accessible. So, people using different software platforms can still retrieve that data and use it for its own purposes.

Sustainable methods for stripping and cleaning elements are part of WP3’s objectives. Can you discuss the methods being developed and how they comply with health, safety, and environmental regulations?

K: This task is concerned with developing methods for cleaning and stripping deconstructed elements from old plastering, paints, tiles, wiring and wallpapers and for cutting and refurbishing components and retrofitting them for new designs. The first stage of this task is to make an inventory of currently available methods. We will also look at and evaluate different methods for cutting such as with track saws, flats slab saws or CNC robot cutting.

All the methods must comply with rules and regulations concerning health and safety in the workers environment. This includes a limit value for dust and the use and handling of solvents. This also includes methods for ventilation as well as methods for sealing off working zones. The methods must also comply with environmental regulations.

What is the significance of evaluating the cost efficiency and sustainability of the methods for cleaning, stripping, and refurbishing components? How do these methods contribute to the circular economy?

K: By evaluating the efficiency and sustainability of methods for cleaning, stripping, and refurbishing, we provide the industry with a list of available methods that can help promote reuse as a possible alternative. We would like to show how those methods comply with regulations concerning health and safety. Reconditioning is an essential part of the process. By showing how it can be done, it is more likely that people will tap into that and want to be a part of the process.

RFID-aided logistics is a crucial aspect of WP3. Could you provide examples of how RFID technology is applied in practical pilots within the project, and how it impacts the logistical processes?

K: We have already done some laboratory tests to check out how the electronic tags can be attached to the physical elements and how they might be protected as well as how factors can affect the readability of the tags. We have also been looking at different digital technologies for connecting the tags to databases and building information models.

The next step is to do some field tests of different tags to find out how they perform in different real-life scenarios in a logistic process. After that, we will be evaluating a selected number of technologies in the pilot projects of the different country clusters. The purpose of those tests is to see how well they can be used to register the travel of the elements but also how the tags can be used as the means to connect to a digital model for retrieval and uploading of relevant information.

Finally, could you highlight the key deliverables of WP3, including the common data environment, RFID-aided logistics, and the processing of deconstructed components? How will these deliverables benefit the construction and AEC industry in the long run?

K: The common data environment plays an important role in making information available to different actors and stakeholders in a reuse process. Our deliverable includes a description of the fundamental principles of making data accessible in common repositories but also on how to ensure interoperability (or how to make that data useful across different software platforms) and the benefits of using open file formats. We will illustrate those methods and principles through practical examples such as by showing how different kinds of data are stored and used to create a digital model and how that model can be populated with data from the various stages of the reuse process.

One objective of our work on RFIDs and tags is to show how the tags can be used to follow and register the location and movement of the elements. In addition to that, we will show how the tag can provide a link to digital information associated with the element. Until now, we have done quite a comprehensive literature study of the available technologies for tagging prefabricated concrete elements. In essence, this means that we have compared the functionalities of different tag technologies such as QR codes, active and passive RFIDs, NFCs and Bluetooth. This comparison includes the reading range and ability to store and retrieve data as well the possibilities to use widely available handheld instruments such as mobile phones but we have also done tests on different methods for attaching the tags to concrete and how this may affect the performance of the tags.

We want to deliver a range of applicable methods for the processing of deconstructed components. As I mentioned earlier it is important that those methods are sustainable and economically feasible but also that they can be implemented in compliance with regulations concerning health and safety.

In general, our cooperation with industrial partners and tangible examples of implementation that include full-scale testing in the pilot studies are central to the relevance and quality of our work and deliverables.

What inspired you to become involved in the ReCreate project, and can you share a bit about your personal background and interests that have shaped your role as the WP3 leader?

K: My background is in building technology or architectural engineering with some focus on how to construct buildings and how to evaluate building performance such as in terms of energy use and environmental effects. Recreate is to me a part of the transition towards more sustainable construction and with my interest in Building Information Models (BIM) and digitalization; it is very interesting to investigate how digital technologies especially can be used to facilitate the reuse process. I would like to show how it can be more effective and how can we gather information and evaluate and analyse things. Having the possibility to put the theory and methods to the test in a practical context is also a very valuable factor.

Would you like to give some conclusion to wrap up everything that WP3 does or ReCreate project is itself?

K: Great thing is to meet all the people involved and to realise what you can do with such a good team.

by ReCreate project

May 10, 2024

In this exclusive interview, we delve into the pioneering work of Patrick Teuffel, founder of CIRCULAR STRUCTURAL DESIGN, as he leads the charge in revolutionizing structural design for a circular economy. With a focus on sustainability and decarbonization, Teuffel discusses his role in the ReCreate project, shedding light on innovative approaches to integrating reclaimed precast concrete elements into new constructions. From reimagining design processes to the challenges and benefits of incorporating AI, Teuffel provides invaluable insights into shaping a more environmentally responsible future in construction.

1. Can you please introduce yourself a bit, your organization and your role in the project?

As founder of CIRCULAR STRUCTURAL DESIGN, I am strongly focused on advancing the principles of the circular economy and decarbonization within the built environment in the context of structural design. With my background as a structural engineer, I bring a strong combination of technical expertise and sustainability principles to my work. As an academic as well as professional, I am committed to revolutionizing traditional construction practices by integrating circularity and sustainability into every aspect of the design process.

In addition to my entrepreneurial pursuits, I also act as a professor specializing in Innovation and Sustainability Strategies at SRH Berlin School of Technology. In this role, I have the opportunity to impart my knowledge and passion for creating more environmentally responsible solutions to future generations of professionals. My advisory role at the DGNB (German Sustainable Building Council) Innovation Board and the circular construction team at Circular Berlin further underscores my dedication to driving meaningful change within the industry.

At CIRCULAR STRUCTURAL DESIGN, our mission is to seamlessly integrate the principles of circular economy and sustainable design into every structural project we undertake. Our approach is guided by three core principles:

1.) Minimizing waste and emissions: We prioritize minimizing resource consumption and emissions associated with our structures, ensuring that our designs have minimal environmental impact.

2.) Keeping products and materials in use: Our commitment to extending the lifecycle of materials, components and buildings drives us to promote high-level reuse and repurposing wherever feasible, thus reducing resource consumption and waste generation.

3.) Using renewable resources: In response to the ongoing depletion of finite resources, we actively explore and incorporate renewable material options whenever possible.

It is our mission to bridge the gap between research and practice and to integrate the principles of circular economy into everyday structural design projects.

Within the ReCreate project I am the lead of the WP5 that explores aspects of redesign and reassembly. I, as a structural engineer, focus on the implications for the design process and the actual technical and practical implementation in the context of the reuse of existing components.

2. Can you provide more information on your work package and how it contributes toward the project?

WP5 consists of two parts: redesign and reassembly. We explore design implications of the stock-based design and develop new connection types or put existing connections to the test to reconnect existing precast concrete elements.

Traditionally the design process follows a linear model. The building design is developed first and the required structural elements, that are needed to accomplish this design, will be manufactured from scratch according to the dimensions required for the project.
The whole work process needs to be rethought when it comes to reusing elements. When maximizing the integration of reused elements in a stock-based design approach, the traditional design approach of form-follows-function will be replaced by a new principle: form-follows-availability.

To enable the load-bearing reuse of existing components, connection details are required with which these can be reconnected. This is why the documentation of connection details that already exist and allow for an easy reuse and developing new connection details that will also allow for an easier future disassembly are the second focus point in WP5.

Perhaps the most interesting thing about the ReCreate project is, that these approaches are not only theoretically explored, but will be implemented in real live pilot projects. Hence a large part of WP5 is designing those pilots and sharing the lessons learned throughout the process.

3. Tell us more about task 5.1 on the framework of parameters for the development of the redesign and reassembly process for precast concrete elements in new buildings?

As stated, the design process is completely different from the status quo, when it comes to the integration of reclaimed elements. Here, the first step is to capture relevant information about the reclaimed precast concrete elements in order to know where and how those may be reused. So, the first thing you need to know is what those elements are. In task 5.1 we explore, what parameters and object properties need to be gathered and at what design stage different information needs to be available to enable architectural and structural design. Here, we are looking at typological and dimensional information and the structural capacity of the different elements.
This task closely interacts with other working packages, such as WP1: the analysis of precast concrete systems, WP2: the deconstruction as we are strongly interested in the shape and capability of each element after deconstruction, WP3: the logistics and processing and WP4: the quality management.

The knowledge gained through this process will be captured in a design guideline (deliverable 5.1) at the end of the project.

4. How does Task 5.3 highlight the challenges and complexities faced in the architectural and structural design process when reusing precast concrete elements?

Task 5.3’s focus is the understanding and developing of a design approach and actively implementing it in the design process in the pilot projects. The traditional approach of an architect developing a space concept first and an engineer designing the structural elements afterword to erect this space does not work when the pool of existing elements limits what they might be used for. Means: the design process needs to run “in reverse”. To understand the capability of the existing elements and what uses they can be put to, requires a close interaction of architects and engineers from the very beginning of the project.
Each country cluster approaches this separately and faces different architectural and structural challenges. Those experiences are discussed within the ReCreate project team and the experiences will be summarized in the form of a best-practice recommendation that incorporates the lessons learned from the project.

5. How does Task 5.3 propose to incorporate artificial intelligence (AI) and neural networks into the design process? What benefits are expected from using AI in this context?

When it comes to designing with reclaimed elements, different design approaches can be explored and different country clusters follow different approaches of how to start with a stock of reclaimed, prefabricated concrete elements and get to the finished product: a building partially designed from those elements.
That insights gained and lessons learned will be gathered in a design manual that will be published as D5.1 at the end of the project.

Generally, the most straight-forward approach to designing with precast concrete elements is trial- and-error.

The larger the implicit knowledge about the reclaimed elements and reuse options are, the better the outcome will be.

Another possibility is a design optimisation aided by parametric design tools. Within the project research is undertaken how the design process can be aided by existing and newly developed design tools that allow for an optimisation.

Also, an AI-aided element matching between a pool of existing elements and a proposed new design will be explored. Especially when the list of reclaimed elements is very large, human trial-and-error can reach its limits. The AI-aided approach tries to do a first step by exploring a matching algorithm that highlights optimisation potential and best matches.

6. Can you tell us more on the processes and challenges that you are facing with the connections in task 5.2 and how do they influence the rest of your work? What are some of the risks that are present here? In the context of design for disassembly (DfD), how does Task 5.2 investigate the possibility of easier deconstructability in the new connections?

The feasibility and ease of new structural connections construction for reclaimed element has a large impact of the likelihood integration of reuse structural elements. In WP5 options to reconnect those structural elements will be explored. Particular attention is paid here to when the same connection points can be reused (with minor adjustments) during reinstallation. The connections that are to be used in the construction of the pilot projects are described. New connection types are also being developed in the project, those put a great emphasis on the possibility for a simple future deconstruction.
The general approach in the recreate project is, that both, new connection details that allow for an easier future disassembly are being developed in project funded university research studies. At the same time in the real life pilot projects conventional connection details that already exist, might also be used.

7. What is the relationship between the re-use of precast concrete elements and sustainability certificates, such as DGNB as discussed in Task 5.3?

When it comes to evaluating the sustainability of the reuse of precast concrete elements from an ecological viewpoint, two aspects can be highlighted. The reuse may help to save both finite resources and avoid new production emissions.
The topic of resource conservation in the context of a circular economy has recently come increasingly into focus, and green building certificates are trying to account for it. One example is here the the DGNB, where I am a member of the committee for lifecycle and circular design, the “DGNB Ausschuss für Lebenszyklus und zirkuläres Bauen“.

Important aspects such as reuse and deconstructability, which are addressed within WP5, are discussed here.

Additionally, a buildings carbon footprint is of course an important aspect to consider when it comes to evaluate the overall sustainability. Within WP5 internal meetings, the use of “LCA-as-a-Design-Tool” is repeatedly addressed. The goal is to actively identify and prioritize the lowest-emission design variant through regular design-integrated LCA (Life Cycle Assessment). Here we also closely collaborate with WP6.

8. How does Task 5.4 ensure a smooth implementation of the four real-life pilot projects, considering factors like transportation, supplementary materials, and equipment?

Let’s have another interview next year, then we can answer this question 😊

9. Who is Patrick Teuffel when he’s not working on the project and what does he like to do in his free time?

As for my personal preferences, I thoroughly enjoy engaging in sports like running and mountain biking, finding exhilaration in the great outdoors. Additionally, I have a passion for savoring good food, particularly exploring diverse culinary experiences. Living in the vibrant city of Berlin, I find immense pleasure in attending concerts and immersing myself in its dynamic cultural scene. Furthermore, I have a strong interest for exploration, fueled by my love for traveling and exploring the world, seeking out new adventures and experiences wherever I go. Last, but not least, I’m doing the final editing of this text in a spa – now you know where you can find me on a Sunday afternoon.

by ReCreate project

April 19, 2024

We are privileged to continue our interview series featuring the talented individuals behind the ReCreate project. In this edition, we showcase Paul Jonker-Hoffrén, who focuses on policy issues related to circularity in construction and labor market.

Can you introduce yourself a bit, and tell us about your background and role in your institution and the project?

I’m originally Dutch, but I’m living in Finland. I have a background from the Netherlands in public administration and public policy research. It involves policy analysis studies and a bit of law in economics and sociology. However, until this project, I did not deal with it professionally. In Finland, I got my doctorate in labour sociology. In Finland, I’m working on labour market issues in labour market relations issues, such as relating to self-employment, the possession of labour unions etc. ReCreate Project to me is an opportunity to combine public administration and public policy research with labour market issues. In this project, I can focus on the policy aspects of circularity in construction as well as labour market issues. In my Work Package, we study work processes and the skills needed in the future to maintain the labour market for construction.

Can you provide an overview of your Work Package, its objectives and why are policy support and social acceptance important for reused precast concrete components?

My Work Package has two distinct things. The first one is about policy regarding circularity in construction and how those policies relate to legislation. The second is focusing on work process analysis. I’m not interested in how many people will be working in a circular construction, but I’m interested in studying how the work of current builders, architects and civil engineers would change through the idea of circularity. For some of them, things will change, and for some, it won’t. For example, for architects, we have to invent new methods. Regarding its objectives, they are here to make visible the policy environment in which this reuse happens and what kind of impact it has on work processes.

It is important to know where the material comes from. If you think of demolishing whole city blocks of obsolete buildings and when you apply the ReCreate methods or any kind of reuse to that kind of scale then you also have to include the social aspects of this reuse because you have to have in mind that people who are living in those buildings have to go somewhere. Including all of this, social acceptability is important in the scalability of reuse because there has to be enough social support for this kind of urban renewal program.

What specific stakeholders are involved in the examination of legal possibilities and barriers at the EU, national, and local levels for the reuse of precast concrete components?

Our second deliverable in this Work Package answers this question, but it is not public yet. There is a lot of EU legislation on this and there are many directives which are involved. For example, the revision of the waste directive is now translated into National legislation and it will become active in 2028 or later. As this project ends in 2025 it won’t apply to us in that sense so at this moment we depend on National legislation. In the second deliverable, we have an overview of the valid norms for our four countries. It includes information on building permits, environmental law, work safety, waste issues and that kind of material standards (what kind of material should be used).

At the local level, you have many different stakeholders in the legal policy environment and they vary a lot between our countries. That is because you have, on one hand- administrative rules, and on the other- responsibility for supervising construction safety.

How does the evaluation of social acceptability differ for the stakeholders involved in the circular value chain, including the impact on work and employment for the company stakeholders?

The social acceptability for stakeholders begins with profitability. For example, in Germany, there is quite a lot of experience with reusing concrete elements for various purposes. There are traditional DDR styles, big houses, but people are leaving because there’s a lot of free housing or empty housing- houses are too big. The solution was to cut off the top floors of this DDR building and make what was left into more modern and smaller housing units. Instead of crushing all the concrete and putting it on the roads or using it somewhere else, they use the elements to build new houses.

Do you think that the part of Germany will be revitalized in a sense and that it will result in it being more desirable for people to move back there?

That is the idea. These new buildings are more desirable to live in. It seems that not a lot of people want to live in DDR flats anymore. If you look at reuse, especially in social acceptability, then the German case is specific on the topic of social acceptability because there is the former Eastern Germany and the migration away from there which causes an oversupply of housing. Finland has also noticed a kind of migration from small rural cities to the south of Finland or cities that have universities, but currently, it is not nearly at the scale of Germany. In the Netherlands, there are 50s and 60s housing estates which are not so desirable. The problem in the Netherlands is that there is not enough space. In terms of migration into the cities, there is an opposite tendency.

What are the key legal possibilities and barriers that need to be assessed concerning the reuse of precast concrete components throughout the circular value chain?

The key problem is, if you deconstruct a building, then those materials should not be wasted. In the EU we have end of waste status, which in Finland and Sweden is already implemented. If you deconstruct a building then you can apply for end-of-waste status. This means that it’s not building waste, but a potential new resource. It is very important in terms of legal and policy environment because as long the element is in the building there is no problem, but as soon as you take it out then it could be potentially waste and it is not reusable. In different countries, there are different routes to get to that status and it involves, in a very early stage, construction or deconstruction project leaders who have to be in contact with authorities that approve elements. You always need aspects like the structural characteristics of building materials that are acceptable and make sure that there aren’t hazardous substances.

Other than that, there are not so many reasons why all of a sudden the same material should change its legal status from when it’s in a building or out of a building. Building materials should always be safe and good to use, if they don’t meet the standards then you shouldn’t use them. Authorities are not entirely sure how this works and what kind of test of building material it should require. This is what we do in ReCreate.

To get the national authorities to implement these practices that we are developing for the project, would it be easier to go and advocate this directly to the European Union, which would then modify the legislation and then send it to national legislation, or it is better and quicker to advocate it directly to National authorities?

Construction project regulation includes many of these things and it is such a document that National authorities have to refer to. Also, you have Eurocodes and similar industry norms. They have a national implementation, for example, climate. In Finland, you have higher snow load criteria than in Italy. It is not so much a lack of legislation, but more a question of what information the authority accepts and what information the authority requests. It is not only the skills of architects and engineers, but we also have to talk about the building inspectors who can check the building permit applications.

How does this WP aim to systematically assess the social acceptability of the reuse of precast concrete components for the relevant stakeholders, particularly considering work and employment aspects?

That depends on the national circumstances. We are interested in the companies involved. Concrete-producing companies are involved in the project. In the Netherlands, there is a concrete agreement (kind of a sectoral agreement) on how to reach the emissions goals for that specific sector. At that level, I would say that they don’t have much interest in reuse because these other waste to reduce emissions are much closer to their normal production processes. This means if they can innovate, they can jump on the circularity train. Reuse, as we do in ReCreate, may be difficult for them because they’re standard way of doing business may be completely rethought.

Do you think that the market can add additional value to their business by buying older buildings (that no one wants to live in) for cheap prices and then selling these precast concrete elements for companies that want to use them?

That is one potential direction which is quite close to what the Dutch company is doing. The benefit of these concrete production companies is that they have so much information about their product, as well as all the equipment they need. I could envision that in the future these concrete production companies become kind of knowledge-producing, because in the processes that we have in ReCreate (and hopefully soon elsewhere) everything in the end turns on the availability of information because all the parties involved in the value chain need information. It’s still a bit unclear what exactly is the information needed at which stage. On the other hand, concrete produces can relatively easily produce all this information that is needed about the concrete elements. In that sense, I could imagine that if they start to move in that direction, instead of making concrete they could make digital twins of these older elements which have loads of information about them.

Do you have some intrinsic motivation for the ReCreate project and what motivates you to work on it? Do you think that we will achieve our climate goals by 2050?

I’m a bit pessimistic. I see a lot of potential here in this project. It is important that we can show all the methods, the materials and all the emissions impact of these pilots vs. normal buildings. But, if you want to make a difference you have to consider vast amounts of construction. For example, in the Rotterdam case, one consultancy firm used the kind of historical BIM model to estimate the amount of material that would be freed up from all the plant deconstructions in Rotterdam until 2030. Then you can make a big difference. The problem is, when you consider that kind of scale, you run into social issues. Calculations on paper are fine, but the point then becomes extremely political in the sense that someone has to decide what these materials are used for. That is a difficult problem because you have the municipality which has housing policies and interests on how much of what should be built; you have housing corporations which want to make money. In the Dutch case you can’t make much money with social housing, so technically or financially speaking they would probably build other than social housing except they are bound to build mostly social housing. For people who are living or want to live in the city, you have this kind of vague political pressure on what the housing market should look like, but there isn’t a right answer to that because it depends on which actor you are. Here you run into a political economy issue that, at best, is a compromise between different interests. In that way, I’m pessimistic because I see technical possibilities of these methods, but socially and politically is much more difficult than we may acknowledge.

Do you have anything else that you want people who read our website to know about your work package or yourself?

I think it’s very positive that also authorities are very pragmatic and they see that there is a connection between these abstract climate agreements and what they do. I always like to say that implementing circular construction is something which happens at the local level because in the end it is municipalities which sign off the building permits and they have local climate plans and housing plans for new and old areas. Even though we have great national and international plans and agreements, I think that important work is done at the local level by all the firms involved, civil servants and other authorities involved. It is important to remember that climate policy is not something that is somewhere out there, but it is really involved in local decision-making.

I: To top it off – who is Paul Jonker–Hoffrén when he’s not working on the ReCreate project and when he’s not working at the University?

P: I’m interested in football. We have a summer cottage which I maintain. One of my main interests, apart from work, is music. When I have a free moment I listen to music. I used to play guitar and bass, but I switched to modular synthesis.

In summary, the interview with Paul Jonker-Hoffrén offers valuable insights into the intersection of policy, social acceptability, and circularity in construction. Through his expertise, we gain a deeper understanding of the challenges and opportunities inherent in the ReCreate project. Paul’s discussion highlights the importance of navigating legal frameworks, engaging stakeholders, and addressing social concerns to foster sustainable practices in the construction industry. His remarks emphasize the significance of local decision-making in driving meaningful change and advancing climate goals.

by ReCreate project

June 19, 2023

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As part of the activities under Work Package 2 of the ReCreate project, our project partners developed a BIM-based pre-deconstruction audit. We sat down with Marcel Vullings from TNO to gain more insight into the audit and to get more details. Here’s our full interview with him:

I: What is the main focus of the pre-deconstruction audit in the ReCreate project?

M: The main focus of the pre-deconstruction audit in the ReCreate project is to gather and validate the information that is crucial for the deconstruction process. This involves putting significant effort into tasks such as inspecting archives, conducting inspections and testing, and ensuring the traceability of information. The goal is to establish a comprehensive understanding of the structure and elements involved, making connections between the gathered information and the actual components. By undertaking these steps, the pre-deconstruction audit aims to provide a solid foundation for the subsequent deconstruction activities.

I: What type of data is gathered during the survey of the existing building in ReCreate?

M: The pre-deconstruction audit process begins with gathering information from the archives to prepare for the building inspection. Once the necessary preparations are made, the next step is to inspect the building itself. Before conducting the inspection, it is important to strip the building of loose items such as carpets and wallpaper to ensure clear visibility of the structural elements. This provides an opportunity to thoroughly examine the structure.

During the inspection, several factors are considered. The overall state of the structure and its elements is assessed, looking for any signs of damage, cracking, or corrosion. Deviations from the norm are noted, such as brown spots that may indicate possible corrosion. Detailed documentation is crucial, including taking pictures and measurements of cracks and other issues. Videos are recorded to allow for a review of the inspection back at the office. Both overall views and close-ups of specific details are captured.

To ensure accurate understanding, it is important to make sense of the gathered information and create a cohesive narrative. Measurements of various dimensions are taken, and a comparison is made between the building’s drawings and its actual construction. Changes may have been made over time or during the building process. Digitalizing the building, its structure, and its elements is also part of the process, utilizing different types of measuring devices.

Finally, both the interior and exterior of the building are inspected to ensure a comprehensive assessment.

I: How is the identification system in ReCreate utilized to trace and couple physical elements with data?

M: Tracking and tracing each separate element is of utmost importance throughout the entire process. This is essential because when designing a new structure, structural engineers need to provide calculations, reports, and drawings to demonstrate that the structure is safe and compliant with regulations. Various checks, including those by municipalities, are conducted to ensure that each part of the structure performs as specified in the documentation.

For reused elements, the information associated with each element is crucial. Any mix-up or uncertainty regarding the information of a particular element can have severe consequences. Therefore, if there is any doubt about the information of an element at any point in the process, it cannot be reused and becomes useless. The objective, however, is to reuse elements whenever possible.

To achieve effective tracking and tracing, it is essential to connect the information to the corresponding elements such as columns, beams, walls, slabs, etc. This can be accomplished by attaching tags to the elements during the initial phases of deconstruction or up until the moment an element is deconstructed. It is crucial not to delay this process. The location of an element in the old structure serves as the only clue to establish the connection between the physical element and the associated information.

Tags can take the form of marks, such as barcodes, QR codes, or plastic tags placed on the elements. Alternatively, electronic tags can be used. These marks and tags need to be secure and durable enough to withstand deconstruction, transportation, storage, handling, reconstruction, as well as exposure to various weather conditions, heat, and sunlight. They must be foolproof.

In addition to secure marking, establishing and maintaining a robust connection with a database or information system is essential. Building Information Modeling (BIM) models of the elements can also be utilized to ensure a continuous and reliable link between the physical elements and their corresponding information.

I: Why is it important to identify hazardous and/or toxic materials before dismantling a building in the ReCreate project?

M: Strict regulations are in place to address hazardous and toxic materials, aiming to establish and uphold a healthy work environment for workers, ensure the well-being of the surrounding area, and contribute to a healthy overall environment. It is crucial to adhere to these regulations to create a safe and sustainable space. Materials falling under this category cannot be reused and must be handled separately and disposed of in a safe and environmentally friendly manner.

To effectively manage these materials, it is essential to determine their presence within the building. For instance, in the case of asbestos, special suits are required for safe removal. The process of identifying and dealing with hazardous materials is subject to scrutiny by the department of health. Mistakes in handling these materials can have severe consequences, including loss of life or significant fines.

Compliance with the regulations ensures the protection of both workers and the environment, emphasizing the importance of following proper protocols for the safe removal and disposal of hazardous and toxic materials.

I: What methods are used to record visual or detectable damage to elements in the pre-deconstruction audit?

M: At various stages throughout the process, the structure and elements undergo inspections to assess any damages, degradation, or cracking. These inspections occur from the initial assessment until the element is reassembled in a new building. The goal is to determine whether an element can be reused and ensure its proper performance throughout its new lifespan, which could extend for several decades or even longer.

Inspections rely on a combination of visual examination by experts, along with the use of pictures, videos, and electronic measuring devices such as point cloud measurements. Additionally, simple tapping on the surface of the concrete can provide valuable information. Specialized equipment like the Schmidt hammer and ferro scanners may also be employed for more detailed analysis.

However, it is crucial that these inspections are carried out by specialists, as not every crack or damage is necessarily catastrophic. Concrete structures commonly exhibit cracks, which are even accounted for and described in the Eurocodes—design standards for concrete structures. The size and location of cracks play a significant role in assessing their impact and determining whether they conform to acceptable limits. Therefore, the expertise of specialists is vital in accurately interpreting the findings of these inspections.

I: How does the surveying process in ReCreate address stability issues during deconstruction?

M: Before carrying out the deconstruction itself, a structural engineer investigates the precast concrete structure to determine the optimal approach for dismantling the building, including the sequence of removing each element. This process must prioritize safety and ensure the stability of the remaining structure throughout the deconstruction process. To achieve this, a comprehensive deconstruction plan is created, which may involve implementing measures such as temporary scaffolding to stabilize the structure during the deconstruction phase.

I: What information does the survey aim to gather regarding the construction methods and structural systems of load-bearing elements?

M: This process can involve a considerable amount of technicality, but it can also be straightforward. Take, for instance, the location of a building, which provides valuable insights into its wind loading. Various factors differentiate a building situated at sea, inland, on an open plain, or within a city. Additionally, the dimensions of the building are crucial. Larger buildings must withstand greater and higher wind loads compared to smaller ones. However, for a structural engineer to accurately assess the load-bearing capacity of each precast concrete element, precise knowledge of the element’s location, layout, and dimensions is required. It is also essential to have information about the material properties of the steel and concrete, as well as how they are interconnected within the structure.

Furthermore, even the positioning of an element within the building, such as a column, provides relevant information. A ground-floor column typically exhibits greater load-bearing capacity than a column located at the top of a building. All of this information serves as valuable clues to determine the load-bearing capacity of each precast concrete element. The more comprehensive the available information, the more accurate the assessment becomes. In essence, if the dimensions of an element, a detailed description of the reinforcement, and the correct material properties are known, a structural engineer can reverse engineer the load-bearing capacity of that element. This process can be complex, but having additional information significantly simplifies it.

I: How does the acquired knowledge during the survey stage contribute to deconstruction planning in ReCreate?

M: Yes, this information is crucial for creating a deconstruction plan and ensuring the feasibility of the deconstruction process. Without it, the undertaking becomes unsafe and hazardous. A comprehensive deconstruction plan is essential, requiring detailed information about the building, structure, materials, connections, and the shape of the elements, among other factors. For instance, if the method of connection between elements is unknown, it becomes challenging to determine the appropriate cutting approach to separate the elements from the structure effectively. Consequently, incorrect cutting can lead to damage and render the elements unusable.

I: How does the pre-deconstruction audit combine modern survey technologies with traditional building surveying techniques?

M: During the audit, a wide range of methods are employed, with each task requiring its own specific technique. Various techniques and tools are utilized to simplify the process and gather accurate information quickly and reliably. These techniques and tools can be quite straightforward, such as visual observation, using a simple ruler for measurements, or employing a laser scanner to measure distances. Drones may also be employed to access challenging locations, such as high facades of buildings. Ferro scanners play a crucial role in detecting reinforcement within the concrete elements, while even a loupe can be utilized to measure the width of cracks in concrete. Additionally, pictures and videos are used to digitally measure elements. The available range of techniques and tools is extensive, offering a diverse array of options for conducting the audit.

I: What role does non-destructive electromagnetic and radar identification play in the ReCreate project, specifically during the survey of the donor building?

M: The non-destructive nature of obtaining information from precast concrete elements is evident, as the goal is to avoid damaging or destroying the elements in the process. Therefore, techniques employed to gather information must be non-destructive. In concrete, one critical aspect of obtaining information pertains to the location and dimensions of the reinforcement within the precast concrete element. These factors determine the element’s load-bearing capacity. Concrete elements require steel reinforcement, with concrete handling compression and steel managing tension—an ideal combination.

Steel can be detected using magnets, whether traditional or electronic magnets utilizing electromagnetics. A scanner is used to glide over the surface of the concrete, while the magnets detect variations and discrepancies. The scanner’s software interprets this information, providing readable details about the reinforcement within the concrete element. However, it is important to acknowledge the limitations of this technique. In certain situations, these methods may not be entirely reliable. To ensure accurate findings, it is essential to gather collaborating information from various sources, such as drawings, old calculations, and even resorting to destructive testing if necessary. Destructive testing involves breaking a portion of the element to visually examine it. Although this may result in sacrificing some elements, it becomes a last resort when other methods fail to provide satisfactory information.

I: How does ReCreate plan to bridge the gap from deconstruction to controlled disassembly for future buildings?

M: ReCreate plans to bridge the gap from deconstruction to controlled disassembly for future buildings through extensive data gathering and knowledge sharing. The project aims to learn from real-life pilot projects, examining what works, what doesn’t, and identifying areas for improvement. One important observation made during these pilots is that plastic tags are not suitable due to the fading of text under sunlight, rendering them unreadable. This highlights the need to explore alternative tagging methods.

Various methods of cutting through elements were explored, including sawing (using blades and cables), drilling, and high-pressure water jets. Each method has its pros and cons, and it is essential to understand and utilize them appropriately. There is no one-size-fits-all approach or tool for deconstruction. Efficiency and safety must be combined, taking into account the specific requirements of each project.

The ReCreate project, with its pilot projects conducted in different countries, aims to collect valuable data, information, and experiences. This wealth of knowledge is expected to have a significant impact, benefiting numerous projects in the future. TNO, as part of the project, plans to apply this new knowledge to other projects, including different types of deconstruction projects such as infrastructure, as well as exploring other materials like steel and wood structures. The research conducted within ReCreate has the potential for widespread application across various domains.

I: What role does cost-efficiency play in the development of the pre-deconstruction audit process in ReCreate?

M: Cost-efficiency plays a significant role in the development of the pre-deconstruction audit process in ReCreate. Currently, cost remains the primary factor driving the choice of methods for recycling concrete structures. Traditional demolition is often perceived as the cheapest option and, consequently, the most widely employed approach, despite its limited environmental friendliness. However, there is a need for a shift in societal mindset towards normalizing the reuse of materials and products as the first and natural step, rather than defaulting to purchasing new ones.

Lowering the costs associated with deconstruction and the reuse of precast concrete elements is a crucial objective. In this regard, ReCreate’s efforts are commendable, as the project strives to provide valuable services in enhancing efficiency within the field. Furthermore, implementing regulations and other measures can contribute to achieving cost efficiency and promoting sustainable practices in the industry. By addressing cost barriers and highlighting the economic benefits of deconstruction and material reuse, ReCreate aims to drive the adoption of more environmentally friendly practices in the construction sector.

I: How does ReCreate aim to optimize the detection methods in relation to the prefab systems and decoupling methods?

M: ReCreate aims to optimize the detection methods in relation to prefab systems and decoupling methods by considering them as additional tools rather than the sole approach. While detection plays a role, it is not the sole method employed. The study of original design drawings and calculations serves as the primary source of information for decoupling. Additionally, inspections and a comprehensive understanding of precast concrete structures provide a complete picture of the building. Detection techniques can be utilized to identify reinforcement in connections and other anchor systems where applicable. By integrating various approaches, ReCreate seeks to enhance the overall effectiveness of detection methods in relation to prefab systems and decoupling processes.

I: What is the significance of testing and validating the generic approach developed in ReCreate’s real-life pilot projects?

M: Testing and validating the generic approach developed in ReCreate’s real-life pilot projects holds great significance. It offers a comprehensive understanding of the entire deconstruction and reassembly process involving reused precast concrete elements. This includes all the associated aspects such as life cycle assessment (LCA), life cycle costing (LCC), compliance with regulations, development of business models, effective planning, information management, data gathering, innovative design approaches for structures using reused elements, creation of new connections, and the integration of old and new components through demountable connections.

The ability to observe these processes in real-life scenarios through four distinct pilot projects in different countries, involving diverse organizations and companies, provides invaluable insights. It allows for a thorough examination of the practical implementation of the generic approach, assessing its feasibility, effectiveness, and potential for scalability. These pilot projects serve as a robust testing ground, offering the opportunity to refine and validate the developed approach based on real-world challenges and outcomes. Ultimately, the knowledge gained from these pilot projects will contribute to advancing sustainable practices in the construction industry and facilitating the widespread adoption of the ReCreate project’s principles and methodologies.

by ReCreate project

April 20, 2023

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The success of the ReCreate project would not be possible without the expertise of the people that stand behind it. Our third interviewee is Simon Wijte – Work Package 2 leader and the Dutch country cluster leader. Ivan Fratrić of the Croatia Green Building Council will be conducting the interview. Here is his story:

Hello Simon and thank you for doing this interview! Can you introduce yourself and tell us about your background and role in your institution and the project?

Of course. I’m a full professor on the chair of sustainment of concrete structures at the Eindhoven University of Technology. My work is split between the University and a consultancy office where I already work for over 30 years. In both positions, my work is tied to concrete structures. I also take part in Eurocode meetings. In my consultancy office, I assess a lot of existing structures and damage to structures from which we can learn a lot. For instance, in 2017. a parking garage which was under construction near the Eindhoven airport partly collapsed and I performed forensic research to determine the cause of that collapse. I’m at the chair of sustainment of concrete structures since 2014. and my approach to this chair is more from a structural engineering than a material point of view, taking into account the application and maintenance of concrete structures in buildings. The material aspect is less relevant compared to a situation when you’re dealing with existing concrete structures in outside environments which are much more aggressive. When it comes to concrete structures, my belief is that concrete structures can be used again and again. The building of our faculty is now over 70 years old. A little over 20 years ago, it was renovated, a new façade, new plans and installations, but the concrete structure was maintained. Now already people are thinking of a new renovation which indeed can be done, but the concrete structures should be maintained again. You can do that over and over and in a way that can be challenging. That’s part of my chair. What you’re facing then is all kinds of problems because, obviously, you have to ensure structural reliability. I don’t know how it’s in Croatia and other countries in the consortium, but in the Netherlands, we’re not careful with the drawings of our existing structures. When you want to reuse an existing concrete structure and you have to assess the structural reliability, you would want to know what kind of rebar is in it, and if you do not know that, you try to investigate in order to find out. Those are the things I’m interested in my research and I receive more and more info about this through my work on the ReCreate project.

In your view, what are the professional benefits of working on the ReCreate project?

For starters, I have to mention Prof. Rijk Blok who sadly passed away and who got our university involved in the ReCreate project. He was an assistant professor in our unit on the chair of innovative structural design and since the topic of the project is closely tied to my chair, I got involved. Rijk managed the project, go us involved and made it successful, but after his untimely passing, there was a question on how should we continue with the project. At that point, it was already known that Patric Teufel would leave the university so I was basically the only one remaining. I took the task of being the Dutch country cluster leader and the task WP2 leader and it’s definitely a challenge. It fits the topic of my chair quite well, but the circumstances why it happened are very unfortunate.

That’s actually what I wanted to ask you because the Dutch country cluster experienced a lot of changes, from Rijk’s unfortunate passing and Patrick’s transfer – how did you manage to handle all of that?

There were actually more events than the ones you’ve mentioned that complicated things. When we entered the project, we thought we could have a pilot project of reusing concrete elements on our university’s campus. In the 50’s at the start of the university, there were four larger buildings and a temporary building built in the 50s. Those four buildings got renovated but the temporary building is still there. In that temporary building, there were some precast concrete beams and it was Rijk’s plan to reuse those beams in a fire station that would be constructed on our campus. That plan did not succeed so we had to look for another pilot project. With the help from our partners in IMd, we managed to get in contact with Lagemaat who are performing a challenging and huge pilot project which means that they are already commercially involved in something that is the topic of our project. All in all, personal changes to the project were followed with pilot changes which was challenging at the time.

It really mustn’t have been easy, to say the least. Now that you’ve mentioned the pilot, can you give more insight into the building itself and your role within WP2?

To be honest, if I had a choice, then work package 2 is something that I would not pick in the first place (laughs). It’s also not so much in my field of expertise, but we’re doing our utmost best for the sake of the project. What we noticed after Rijk passed away is that we’re lacking in staff and in knowledge as well. The Netherlands is not that big and we know each other quite well in the Dutch country cluster, so I looked around and found that a person I know whom was an expert in precast concrete elements, but just as I wanted to contact him, he started working with TNO just weeks ago. They obviously didn’t want to let him go, but since they are a knowledge institute, they were keen to participate in the ReCreate project. I’m of the opinion that adding them was a great move as they have great knowledge in terms of structural reliability, LCA, BIM models, and so on. Their participation in the country cluster opened up the opportunity to use their knowledge. Together, we managed to produce the deliverable for WP2, especially with their knowledge of BIM, which can be very helpful with everything we do in ReCreate. In principle, the basis of the project consists of two things, the first of which is the actual precast concrete element. But, additionally, to that, you want to have a lot of information about that element and those have to be connected to the element and have to remain that way so when that element is stored somewhere on the yard, you have to know all the relevant information about it. That is obviously in the domain of Work Package 3, but in Work package 2, before the deconstruction of the building, you have to know what kind of information is available on that particular element and for that, the BIM models are very useful because you can add a lot of information to those models and the challenging thing is that you can make a 3D model of the building that will undergo deconstruction with all the elements in it and then you can deconstruct it digitally, which means you can take them out and put them out into a database. We have to gain experience in that and connect with people with such knowledge as the BIM model and the database that contains all the BIM models of all the elements will be very important through the complete process. It will be important for both architectural and structural designers, as well as for LCA calculations.

That’s actually something that I wanted to ask you as I’ve asked Erik (Stenberg) the same thing. We know what kind of construction the ReCreate project proposes with regards to precast concrete elements and the benefits such as the reduction of carbon emissions and material extraction. That is good all by itself, but I asked Erik whether there are some drawbacks and constraints from an architectural perspective and he said that obviously you can’t do everything with precast concrete elements, so I want to see your perspective as a structural engineer and whether you see any constraints that such construction can have?

Let me touch upon the architectural constraints first. Normally, when an architect starts to design a building, he starts from scratch and its up to him whether the floor span will for instance be 7 or 8 meters. He’s free to choose it. It is completely different when you already have a complete structure after the older façade and separation walls have been deconstructed. When you go from an architectural point while having in mind the usage of precast elements, it’s kind of similar but you’re a little bit more flexible. Let’s assume you have a huge database of all kinds of precast elements that are available for reuse in new structures. Then an architect pays you a visit and says ”I want to make a building with, for example, 200 m2 of the ground floor and 200 m2 of the first floor and I want to see how I can create that using available elements”. That’s where the application that we are working on in WP5 is important as it will tell you the availability of elements in the database. In that sense, the architect has a degree of freedom but could be constrained by the availability of certain elements, as well as their location. In that application all kind of aspects can be considered. For instance, carbon reduction by reusing these elements is good, but if an element you need is in Rome and you have to construct a building in Amsterdam, then the reduction of carbon is gone. From an architectural point of view, when you want to reuse a structure in its place, the constraints are the largest. When you want to create a structure using rewon precast elements, you’re more flexible, but obviously, there are limitations, but those limitations can also be in your head.

And from a structural point of view?

We have to make a distinction between two parts. First on the element level. In the general situation, the elements which are available should be able to withstand the forces that will be applied to them in new structures. So that may not be so challenging until I’m not aware of the reinforcement which is there and I’m not aware of the function of the structure. The second thing is stability – there have to be some shear walls in the structure somewhere to keep it standing up. One of the last challenges is how do we connect the elements. What we see now through the ReCreate project is that disconnecting in majority of the cases is done by sawing structural parts apart and one of my remarks towards that we can do that also in ‘in situ’ structures and not limit ourselves to precast concrete. When demolishing in situ structures, you can also choose to saw off certain elements and try to use them again. ReCreate, as a project, is just the beginning of reuse and is also a small step towards the reuse of steel beams as well…

Now that you mention the reuse of steel beams, do you think that should be also focused on eventually? Do they go hand in hand with concrete elements?

When making the idea for the project, we limited ourselves purposely to precast concrete because if you expand the scope of research, it only gets bigger and bigger and more complicated and greatly expands in scope. But you’ve identified that correctly as the research can definitely be expanded to other things such as steel structures eventually as well. Research on that part is still ongoing. Research is also being conducted in the Netherlands on the reuse of precast concrete bridge girders.

That’s a topic for another project, maybe after ReCreate…

What you see is that a lot of things are ongoing and the tasks of structural engineers and architects is changing. I was educated only to design new structures.

It’s almost completely new science when it comes to ReCreate.

What we now have to do and what we have to educate our students is that in creating new structures, they should also keep in mind that reused elements can again be used or try to design new buildings within older structures.

Now that you mention the students…Simon, do you think that the knowledge that comes from the ReCreate project and the whole practice of reusing construction elements will be adopted and implemented into university curriculums?

It will and already is. I have some lectures on sustainment of concrete structures which is limited but what you see is that, when you look at master research projects done by students before their graduation, is that they are keen on carbon footprint of concrete structures and how that can be reduced. Because of that, we have a lot of students performing their master research projects within our ReCreate project. There’s one student at TNO looking at structural reliability when using reused elements, we have some students working on diaphragm action between hollow core slabs with particular connections so that they can be reused, and we have student looking after the reliability of non-destructive measurements after the presence of rebar, and lastly we also have a student working on how can we create new connections…

So there’s definitely a demand and interest for this topic?

Sure, students are very much aware of the problems we are facing with our environment and take this into account when choosing what they will master in.

Now that you’ve mentioned this, I’d like to return back to you. You’ve said that the students are highly motivated for topics that pertain to climate mitigation and reducing CO2 emissions. What I want to ask you specifically is whether you are a climate optimist or pessimist in terms of our goals for 2050.?

I don’t know whether I’m an optimist or a pessimist. I’m very much aware that things need to change. I try to be mindful of my personal behavior and preferences with regard to my own carbon footprint, but then again I will take a plane when I go for my holidays in the south of Europe. I still drive a car and will strive to buy an electric or a hydrogen one.

You’ve mentioned before that the ReCreate project circumstantially ended up in your hands. Now that you’ve spent some time with it, can you tell if you have any internal motivation or drive that underpins your work on the project?

Absolutely. The motivation for the reuse of concrete was already there from within my chair. I also must admit that the time I could spend on this topic was limited at the time, but ReCreate enabled me to expand the research. The topic in itself motivates me a lot as we need to work on the carbon footprint of concrete structures. The production of cement is responsible for over 8% of CO2 emissions created by people and that’s quite a lot. On the other hand, when you look at the Pantheon in Rome, the building, with a concrete structure stand there for more than 1900 years. Why do we have to demolish the concrete structures we make after just 50 years and create new concrete? We have to face the challenge that we have to reuse the structures that we already built. Reuse of whole structures is almost ideal, but the second best is definitely to dismantle it into reusable pieces rather than demolish it into coarse aggregate because then you have to use new binder and cement, at the cost of additional carbon emissions.

In your view, what is the ultimate goal of the project?

If the reuse of concrete elements in new buildings becomes regular within 10 years from now, then we’ve done a good job. We participate in it, produce new knowledge, and try it in pilot projects…if we are able to change the construction industry in this regard – that should be the goal. This goal will not come overnight even if people are initially for it, if we reach that goal, we’ve succeeded.

So a wider market uptake and a greater number of experts in these fields would be seen as successes of the project?

And also to improve processes for precast structures to make their deconstruction easier. On the other hand, I now have a student looking at a more sustainable design of precast structures of apartment buildings. If you make them easier to disconnect them, it requires less effort for reuse.

How do you manage and what are your thoughts on the collaboration within your country cluster and with other organizations in the consortium?

The cooperation within the Dutch country cluster is good and is getting better with time. I very much appreciate the collaboration with all the other country clusters because everyone is working from their own area of expertise and together we are able to gain all kinds of knowledge on the matter. It’s not just about structural reliability and structural design. It’s about LCA, material research, the digital design process, and so on. I appreciate very much how Satu (Huuhka) and Soili (Pakarinen) are managing this project.

We’re at the end of our interview and I’d like to end it with a personal question. Who is Simon Wijte when he’s not a professor and when he’s not working on the ReCreate project?

I like to do a lot of things. I like sports – both watching and performing. Although I’m becoming an old man, I’m 60 (laughs). I used to play field hockey, but my body doesn’t want it anymore. Now I’ve switched to cycling. I like a good dinner, a good glass of wine and being with my family and friends.

by ReCreate project

March 1, 2023

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The success of the ReCreate project would not be possible without the expertise of people that stand behind it. Our second interviewee is Erik Stenberg – Work Package 1 leader and Swedish country cluster leader. Ivan Fratrić of the Croatia Green Building Council will be conducting the interview. Here is his story:

I: Hello Erik and thank you for doing this interview! For starters, can you introduce yourself a bit and describe your role in the project and your organization?

E: Of course. I’m an architect and an associate professor at KTH Royal Institute of Technology in Stockholm, Sweden and I have a history both as a practicing architect and a teacher I’ve been (for the last 20 years or so) working especially on housing from the post-war period in Sweden and I’ve specialized in prefabrication system in concrete which was used in mass housing during the period from 1965. – 1974. in Sweden which was called the Million program era and how we renovate and update those housing areas. I work a lot with issues concerning sustainability and also technology and history. In ReCreate, I’m the Swedish country cluster leader and I’m also the Work package 1 leader.

I: You’ve mentioned that you have experience with sustainability – can you maybe tell me more about what made you inclined to join the project?

E: There were a couple of major reasons. One of them was to work and collaborate with Satu Huuhka who is an amazing person and researcher so that was very enticing in itself because she’s such an authority on the subject in Finland and has strong connections to Sweden and these other countries. The other one is following the trajectory of my interests and seeing prefab housing from the post-war era from yet another angle and as something positive or in other words as a resource and not something expensive to upkeep and generally as something bad. This is another way to describe the incredible effort of the post-war era and to test it on a 1:1 scale. Basically, I want concrete to be seen as an asset and not a liability. In every sustainability discussion today, concrete is always looked at as a liability – it’s too expensive to make in terms of carbon footprint, it represents a period in history where we were mass-producing housing and we have several words in Sweden when you add concrete or grayness it immediately has negative connotations. This project provides a way to turn that around and see concrete as an asset, as something positive, especially by using high-quality concrete we made in the ’50s, 60’s, and 70’s, we can now also lower the carbon footprint of new construction through it.

Erik Stenberg

I: Moving toward the Swedish pilot and the project itself. Can you shed more light on how you collaborate with other partners in your country cluster?

E: Sure! There aren’t many of us in the Swedish country cluster. There’s Helsingborgshem – a municipal housing company and Strängbetong – a material producer of concrete and KTH. The situation is a little different here in Sweden with regard to the pilot building. Helsingborgshem already has a long-term project on rejuvenating a housing area called Drottninghög, which is a typical post-war massive housing area with 1100 units of housing that are very similar and all built within the same 5-year time span. Now, that area has a weak socio-economical development and they have engaged in a long process of dialogues, they have changed zoning and are even producing new housing. The goal is to increase the number of housing from 1100 to 2600 units by 2030. To do this, they are tearing down some of the original housing which is prefabricated. When I approached them I said to them not to just crush the concrete, but to join the ReCreate project and see how we can actually reuse the concrete – both to provide a better history and a new story on the panels so they are not seen as something bad, but as something good and we also test new ways of sustainable construction. They agreed to this and have actually had a city-wide movement to have a city expo. It was in the spring of 2022. We had a very short time to do a physical pilot in the Swedish country cluster, but with the help of Strangebetong, we managed to build a small physical pilot as an exhibition pavilion for the H22 Expo. We tested the whole process in a physical pilot so we can make a digital pilot which is more precise and better but aimed at the future development of Helsingborgshem’s Drottninghög housing. This is the opposite of some of the other country clusters because we’re first working on a digital pilot to then prepare a larger, physical one.

I: That being said, one can presume that there were no issues with getting everyone on board for the project and that they were quite motivated to join the project and were sold on the idea of it.

E: They were. But again, it’s important to stress that we (the Swedish country cluster) consist of a few members. Part of it can be attributed to the fact that we have the municipal housing company as one member and they have to follow the rules of procurement so we could not have other partners join the team before we went through the process of public procurement so as we build the physical pilot and went through all of those stages we also engaged the construction company and other architects and engineers.

I: Returning to you – do you have some kind of internal motivation for the project? Something that intrinsically motivates you?

E: Of course! I’ve touched upon it earlier and I can say that it’s definitely the high regard for post war housing in Sweden, a subject I have been working on for the last 25 years. That is a very strong driver for me. The other driver is sustainability in the construction sector. As architects, we have to become much more knowledgeable about what the climate impact of what we’re designing. I think that’s where reusing really opens up an avenue where it’s not just about the regard for historic buildings but also how we produce new buildings with a lower climate impact and also a great architectural design.

Erik Stenberg

I: On a broader scale, can you describe why the ReCreate project is important from your perspective and what you see as its ultimate goal?

E: The project is important because it aims to reduce both the carbon footprint and the waste of the construction sector. These are two huge that we have. As a goal – I think if we can provide the tools, methods, and examples to cover some of the value chains, then we will have come a long way in the four years of the project.

I: That’s something that I also want to touch upon a bit further. So the project will last for four years and will officially end sometime in 2025. How do you see its progression after its official conclusion? What do you see as some of the hindrances of its uptake and what are some of the challenges it will be facing once it is over?

I think the business sector will move very quickly with many of these new findings and with the findings other projects are making. In a few years, I think there will be a few business models in action which will continue after ReCreate. I hope to see that there will be more pilots after the project. Those are some of the short-term effects. In the case of long-term effects – I hope we’re also starting to set in motion the way we educate architects and engineers to deal with existing buildings, the way we value the existing building environment in planning processes, the way that we set up future research projects to include reuse in the existing environment. Those are outputs that are just as important, but we won’t see them immediately. Redoing education for architects for instance can take decades. Those are the things that we contribute to ReCreate, but are not yet tangible as of this moment.

I: The process will definitely take time. This will also be a more personal question in that regard – do you think that we have the time for such a steady transition while also having the pressure of encroaching negative effects of climate change? Basically, what I’m asking is whether you have a positive or negative outlook on our chances of succeeding in ”saving ourselves” from climate change.

E: Well I’m very positive that we won’t meet the 1.5-degree goal by 2030. But I have a very positive outlook with regard to the engineering and architecture sector. I think the construction sector is in for a major change but we have faced these challenges before. Maybe not on the same scale and with the same level of threat, but I still think we will be moving ahead with that change even though we won’t meet the climatic goals and we won’t reduce the waste at the EU level fast enough. We won’t solve the problem in four years, but that is something that we need to do for the construction and demolition sectors regardless. We need to contribute and work as hard as we can.

I: Of course. Especially if we look from the global perspective and when you take into account emissions coming from elsewhere. We definitely hope that the findings we produce with the project will be recognized by the market.

How do you find collaboration with other country clusters and other partners on the project? Do you find it challenging or do you find it exciting to work with experts from other countries?

E: Of course, it is a huge benefit. When counting the country clusters and Croatia, there are five different countries in the project. The benefit is also present in terms of the multidisciplinary approach of the project. At KTH, for instance, we have three different departments engaged. It’s very easy to fall into working with colleagues within the same department because those are the ones you see every day and they don’t really challenge your knowledge boundaries. This is really one of the bigger benefits – working with building sciences and the environmental department, as well as the architecture department, we actually have just as exciting discussions here, let alone with colleagues from other countries. It’s not difficult to work with an expert from other countries at all as they are all highly knowledgeable, highly engaged engineers, architects, and researchers. The companies have been really interested. When we had the annual meeting in Helsingborg where it was 40-50 people, we could have easily spent days in smaller meetings just discussing our work. I’ve been part of difficult research projects and this is definitely not one of them. Maybe in its scope, not in terms of people working on it.

I: Of course! When you work with highly motivated individuals, where everyone is an expert in their field, it can garner special results.

E: I would just like to add that this can most definitely be attributed to the way the project was written and the way it is led. The team around Satu Huuhka is doing a great job.

I: Agreed, definitely agreed. Let’s think about the future for a bit. We talked about the market uptake of the project results in the future – do you have some other impact that you would like to see 10, or 20 years down the line? For instance architects – do you think they will have enough creative range for new buildings?

E: I think so and I think this is quite intriguing. The reason I think so is because we have tested it in a design studio in project similar, but not attached to ReCreate. We tested the design with the reuse of prefabricated concrete panels and the students were a bit confounded at first because they are not educated to deal with them. But once they figured it out and understood the limitations they have, they could all devise a strategy or method for using the elements and many of them involved finding new forms or shapes or details of the buildings, which is directly attributed to the reuse of the panels. So they were shifting sizes of the panels, which left gaps or there were structural dimensions that led to certain rooms, sizes, or proportions. There were ways of combining elements that led to also different heights and widths of the buildings. All of these things may seem minor, but I think they are quite important. Now I’m wondering about if whether this is something that just happens in this type of shift or whether it is going to be a reuse style in the end which you can then understand that this is high-quality architecture because it is using reused elements and not because it has a certain color or look or proportion.

I: That’s something we will see with time. How the creatives will utilize it and what they will create down the line. With that in mind, do they have to deal with any technical constraints when reusing precast concrete elements?

E: Yes (laughs). From a technical and engineering perspective there are several issues, but I think that we have enough pilots now historically and Satu knew this when she was writing the project. There have been enough pilots in Germany and even in Sweden and we know that concrete has a longer material lifespan than a building has a socioeconomic lifespan. Cities are being developed and office buildings are being torn down to make room for housing and vice versa. The material can be reused but rules, regulations, financing, and business models is not adapted to this yet. So these are the big technical challenges that are not on the material side. Then, of course, there’s the whole question of knowledge. We’re not educated to deal with the existing environment and now it takes a lot of time to work that way, but in the future, we hope it will take less time.

I: Once the knowledge enters the curriculum, the dissemination of the knowledge should be more efficient. Actually, that is something I want your comment on – do you see the curriculums changing? Will there be some kind of specialization for reuse in that regard?

On a general level, I think we’re seeing small research groups, and small parts of programs being adjusted towards sustainability issues and global climate change is the main driver behind the changes, but the ideas involved in ReCreate can influence them. One example is the Royal Institute of Art in Stockholm which opposed graduate degree in restoration architecture because they started a new program this year in restoring the recent past – the modernist heritage. They are actually starting a new program to engage from a building conservation and preservation perspective, and from a heritage perspective to garner a better understanding of the recent past. We’re not seeing that in architecture schools on the curriculum level yet, but we’ll see it, albeit as small changes.

I: So it is possibly still too early to talk about it. The changes might be incremental, but not paradigm-shifting.

E: I agree. I think there will be incremental changes, although the climate is screaming for a radical change

I: You were present at several architectural events where you represented ReCreate. What was the reaction from your peers and what kind of feedback did you receive from them?

E: Well, they are following ReCreate with great interest. For example, at the Lisbon Triennale we not only exhibited but I was invited as a speaker and when I held a presentation, part of it was about the content of ReCreate. It was received with great interest from all architects. We had architects from both North and South America, Asia, and Australia – almost all the continents were represented. They were all interested in the topic of Terra (the Earth) and different angles on sustainability and I would say it was a surprising and positive engagement with the ideas that I presented. It’s very positive. I usually try to lower expectations because the truth is that currently the rate of reuse in Europe is 0% and the goal is to move to 1% or 2%. Some people might think that we’ll have 50% of new buildings being made from reused materials 5 years from now but that’s not going to happen.

I: Understandable, but the proof of concept is definitely here and it’s definitely exciting.

E: Yeah! I was wondering how the architectural community of exhibiting architects, not just constructing architects, would react to the subject of reuse, but I have found that it was indeed highly regarded.

I: And they will certainly one day be a valuable part of that process. It’s a vast and long value chain of stakeholders and architects are certainly one of the more important parts as they will surely be one of the driving factors behind the uptake of reuse.

E: The exhibit in Lisbon was part of an overarching theme was ‘Terra’ and the exhibit we participated in was called ‘Cycles’ the curator Pedro Alonso from Chile and his partner Pamela Prado made a great selection of different academic professional practices and 15-17 practices that are all working with cycles in their daily projects. So ReCreate was shown among others. We have lots of friends out there and in that group, ReCreate was seen as very hands-on and that can have a very strong impact, which is because of the prevalence of prefabricated concrete as everyone is aware that it is being used all over as a resource.

I: Of course and it can certainly be deduced (even to the wider public) that the project can create great impact, it is very tangible and it can be pitched very easily to other people, which is why it is so widely acclaimed. Working on it can feel like being on the cutting edge of something really important.

E: Yes, exactly!

I: We’re nearing the end of the interview and thank you for your time, Erik. Do you have any closing comments or something you would like to mention with regard to the project?

E: I would just like to stress the collaborative aspect of the project. The EU projects are set up in such a way that you have to collaborate with partners from all over Europe and even across disciplines and I think this one is really critical because the effort to move towards increasing the amount of reuse will need experts from many different areas. It’s not just inventing a new material, putting it on the market, and seeing what happens, but this is about shifting a paradigm and moving the construction sector into a circular movement and we’re contributing towards that.

I: To top the interview off – who is Erik Stenberg when he’s not working on the project and what does he like to do in his free time

E: You’ll most likely find me in the woods or the mountains – basically far away from any architecture. I spend a lot of time with my family and friends in the backcountry, hiking, sleeping in tents, and walking across low mountains as we don’t have high mountains in Sweden. We can move across them easily as there are no dangerous animals, insects, or anything and we have potable water still so it’s a great way to recharge batteries from working hard all winter.

I: I also spoke to Satu and she said something similar, which is why I will use the opportunity to ask whether this has something to do with Scandinavian people always ending up on lists of the happiest people on Earth. Do you think this is true or is it overblown?

E: It s a little bit of a cliche but I think there’s some truth to it. I spent some time in the US when I was younger and I think the relationship with nature there was that nature is something that you conquer and you put up a fence and you own it somehow, apart from here where the dominant mindset is that we’re just borrowing some time from nature to be here and when I go outside the door I’m in the nature, I’m part of nature and I think that, as a mental construct, is something I try to cultivate. When I sit by a blue lake, it’s not because I’m interested in meditating, it’s because there’s some fundamental connection to being part of nature, instead of trying to dominate it, or water-ski. I’m not using the water in that sense. That’s an extreme form of affluence and richness. In most of the world, you don’t have to time or the money or nature to do that, but we’re very lucky in Scandinavia that I can do that. For example in my specific situation in Sweden where I can, for a few weeks a year, just be part of nature and not do anything else.

Erik Stenberg

by ReCreate project

January 3, 2023

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The success of the ReCreate project would not be possible without the expertise of people that stand behind it. Our first interviewee is Satu Huuhka – the project coordinator and the person most responsible for its inception. Ivan Fratrić of the Croatia Green Building Council will be conducting the interview. Here is her story:

I: Hi Satu! Can you introduce yourself a bit, tell us about your background, your role, as well as the role of your organization in the project?

Satu: I’m an associate professor of sustainable renovation at Tampere University School of Architecture. Tampere University is coordinating the organization and implementation of the project and I’m the scientific coordinator and basically the project is my brainchild as ReCreate was born of my initiative. I’m originally an architect and the topic of my masters degree was regarding the reuse of concrete or reusing different kinds of building parts and materials, but with a special focus on precast concrete. Interestingly, the inspiration for my masters thesis came from a relative of mine who sent me newspaper clippings of topics that I would possibly be interested in and one of those clippings was on the topic of reuse in Germany which I found the most intriguing and which incidentally described the work of professor Angelika Mettke who has worked on the topic for 20 years at that time and who would eventually join the leadership here on ReCreate. As for the idea for the project, it began with my colleague Jukka Lahdensivu who is the Work Package 4 leader and eventually ended up as multidisciplinary research, not just architectural and civil engineering, and employing a more holistic approach. My university supports preparing and coordinating proposals so I received a little grant to start building the consortium. Then we traveled to meet people from KTH and other organizations with whom we had previous contact and that we knew had suitable expertise to join the project. That’s how it started.

I: What was your initial idea when forming the consortium? What was the reasoning behind structuring it the way it is? How was the idea for the project received by the partners?

Satu: The idea for the country clusters was present from the beginning and was influenced by another project we are involved in which is called CIRCuIT which is coordinated by the city of Copenhagen but we’re a partner and a WP leader. I think that worked well in CIRCuIT and it made sense for ReCreate because we’re working with buildings, and construction is quite a local activity. It made sense to find universities to be country cluster leaders as they have the capacity to handle the management side of things, the bureaucracy, as well as because of their connections to the local organizations and industry partners that would address this issue in their countries. Everybody was really positive when they heard about the idea for the project and they immediately wanted to be on board, especially the universities. There was some difficulty with industrial partners as we had some talks with organizations that weren’t interested in the end, but our connections enabled us to find partners that wanted to be part of the project.

I: In essence, the universities immediately saw the potential of the project, while the industry needed more nudging in that direction.

Satu: The core activity of universities is research and development, but I think that industry partners were a bit weary of the bureaucracy which these projects entail. That is also why it was important to have these universities at the core of the country clusters to help the companies with the bureaucracy and to take the load off reporting away from companies as much as possible.

I: Of course, so they can focus on the development and implementation of the project.

Satu: Exactly, yes

I: Returning back to you. You said that the project is your brainchild and that it is personally very important to you. Why do you think, on a broader scale, the project is important and what is its ultimate goal?

Satu: It goes without saying that climate change is an issue, along with other environmental issues such as diminishing availability of sand and gravel in some locations. I think that now there’s a consensus in the construction sector that there’s need for change in the way how we’re building. Many European countries are even introducing legislation that requires low-carbon building – and not just with regards to the energy in operation. It is starting to be realized in the construction sector that manufacturing the materials for construction is also carbon intensive and that reusing building parts such as precast concrete helps to reduce that embodied carbon because in that case you don’t need to produce new material as you can just harvest existing elements from buildings that have been slated for demolition, which presents huge potential to cut embodied emissions as professor Mettke’s research has shown, and that’s the reason why we should look into reuse as concrete is used widely and is very carbon intensive as its a heavy material.

Satu Huuhka

I: You’ve mentioned the potential for the reduction of greenhouse gasses and the depletion of raw materials. Do you have any other aspects of the project that you personally find most exciting and compelling?

Satu: I’d say its the multidisciplinary approach that we have. It’s fantastic that we have all these experts in their respective fields, which includes practical experts of the industry partners. The fact that we have these pilot buildings is also really important as I found through my own research that we have reached the limit on what we can do alone as researchers without actually trying it in practice. Since now we have these pilot buildings, our experts can really put their thought into it and what can become reality eventually – not just in the construction aspect, but also in business, the environmental impact, the social impact and how work is changing, what are the architectural implications are, what it means for logistics and digitalization. Seeing all these experts work together is really inspirational for me as I feel that we’re really making a step forward with reuse thanks to all of their expertise.

I: There’s no lack of exciting aspects to the project, but its sheer scope and complexity surely brings some sort of challenges with it. In your view, what is the most challenging aspect of ReCreate?

Satu: Before we started, I already had a preconception that we might have a conflict of interest between the partners or that maybe there would be a risk that the industrial partners would change their minds on whether this is something worth pursuing, but these concerns were not realized at all. All the partners are really invested. The most challenging aspect actually is aligning the ReCreate project timeline with the real world building project timeline, because we don’t want to do something that isn’t really needed as we’d like for the pilots to be buildings that would stay, which is not the case with the Swedish pilot, but in principle, we would like the buildings to stay, so we need these real world collaborations outside of the project to find suitable building projects. That has been a challenge in many locations and we are still working on it. The timelines of building projects are variable – sometimes things happen quickly and in other cases things can stop for years and can then be picked up again eventually.

I: Do you think that negative impact is short-termed or that it could create further issues down the line?

Satu: It’s more about the moment we’re in as it reminds us here in Europe that it’s important for us to be self – sufficient with building materials to mitigate these supply chain uncertainties in the global geopolitical landscape, which also then creates a strong argument for reusing materials that we have here at home.

I: We’ve touched upon it a bit, but I wanted to hear more from your perspective. The ReCreate project entails four different pilots, from four different countries, with a multitude of organizations and companies involved. How do you handle the coordination of all of that as it must be a challenge in itself?

Satu: It is challenging and I’m really lucky that I don’t have to do it alone. Soili Pakarinen’s help as the administrative coordinator is really valuable because she helps everybody with the financial reporting and the country cluster leaders (the universities) are my main contact point to the industrial partners in the other countries and vice versa as sometimes there are language issues as it’s easier for people to operate in their own languages. It is a team effort and Soili, the country cluster leaders, as well as work package leaders are very valuable. So basically I’m not alone because I’m surrounded and helped by brilliant people.

I: The project is really ambitious and we’ll definitely have something exciting to show at the end of it. How do you see the future of the ReCreate project? What kind of impact would you like for the project to have?

Satu: I hope that the industrial partners will be able to integrate the ReCreate approach into their daily business activities and that they will be able to provide these goods, services and expertise. That is our main pathway to impact – that these products and services become available on the market through our industrial partners. I’m also dedicated to keep helping them through new projects if there are still things that remain to be developed. Personally, I’m prepared to help other companies that want to engage in similar projects. Of course, there are also open access documents and publication that will be available for scientists, industry people and even regular people interested in the topic.

I: Thank you Satu for the interview. To end on a more personal note – who is Satu Huuhka and what does she like to do in her free time when she’s not managing the ReCreate project?

Satu: I’m a very work-oriented person but sometimes I do other things in my free time. I like to cook, read detective stories like good-old Agatha Christie. When I have more time, I like to do something with my hands. For example, I live in a traditional wooden Finnish house and I do the conservation work with my husband. Things like window conservation and new felt roofing on the outhouse, as well as furniture conservation.

Satu Huuhka

by ReCreate project

April 29, 2022

Erik Stenberg, architect and senior lecturer in architecture at KTH – School of Architecture and the Built Environment (ABE) in Stockholm, answered a few questions on why reusing concrete is important in urban development projects.

Why is the reuse of concrete important?

– This is where the biggest environmental benefits can be made. If you access the concrete in the structure of houses, you can achieve the largest reduction in carbon dioxide.

Why is it important in urban development projects?

– It is becoming more and more important to look at the entire life cycle and carbon footprint of the entire urban development and not just individual buildings. We have to look at what was there before and what will come after. We need to make better use of the resources that are already above ground. Also, the historical dimension has nothing to do with carbon dioxide pollution, but with cherishing a legacy, taking advantage of what is good and building on it, and improving what needs to be improved.

What are the benefits of using reused concrete?

– This is exactly what we test in ReCreate. The thesis is that the concrete continues to harden during its lifespan and the technical lifetime is much longer than the service life of the buildings. Therefore, reused concrete should be better than new concrete both constructively and environmentally as we do not use and extract resources from the earth’s crust.

So concrete is made to last longer than the time we use it today?

– It lasts much longer. The concrete you usually see is the one that is exposed outwards to the external elements and it is usually hit harder by rain, weather, cold, or salts (depending on where it is) than concrete that has been sitting hot and dry. If the concrete is hot and dry, it lasts forever.

What opportunities do you see when it comes to reusing concrete?

– I look at the material and historical values and that we get a healthier discussion about how urban development should be done, and that we consume fewer resources when we build in the future. This is the biggest change that needs to happen, not just thinking ‘new’ all the time but rather that we take care of what we already have.