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.
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.
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.
Not long after ReCreate was featured in an esteemed Chilean magazine, the project is at it again! Just recently, the project found itself sitting atop the #93 spot on this year’s Maktlistan – a list of the most powerful and impactful in Swedish architecture and design.
The list is created and published by Rum – a well-known and established Swedish architecture journal that recognizes and applauds great achievements in architecture and design, as well as the people behind them. Each entry in the list receives its own whimsy, positive (and sometimes even comical) comment and ReCreate was not ”spared” in this manner.
The authors of the text playfully acknowledged the aim of reducing carbon emissions through the reuse of precast concrete by saying that Mr. Stenberg ”will ensure that the rest of us will be able to breathe” because of the project.’
The ReCreate project would like to thank Rum magazine for recognizing the effort, expertise, and hard work that the Swedish country cluster, along with other country clusters and project partners are investing in the project.
ARQ magazine, a non-profit architecture magazine published by Ediciones ARQ of the
School of Architecture at the Universidad Católica de Chile, published an article on the ReCreate project!
Swedish country cluster leader and esteemed professors Erik Stenberg and Jose Hernandez Vargas, along with our project coordinator and associate professor at Tampere University Satu Huuhka, shared their knowledge on the project and what it wants to achieve.
The article showcases the reasoning, as well as the historic and environmental context behind the idea for the ReCreate project, as well as the methodology and technology that underpin the project. Also, they give a breakdown of the pilot buildings, what were their functions before deconstruction and what elements will be gained from it.
But don’t take our word for it! You can check it out yourself by clicking on the link here!
ReCreate German Country Cluster leader Prof. Angelika Mettke was interviewed for an article in the regional daily newspaper Lausitzer Rundschau and for an online report of the ARD Tagesschau, in which she presented an already realized reuse project in Kolkwitz as well as the plans for the ReCreate research project. In addition to Prof. Mettke, the deconstruction company ECOSOIL (industrial partner in the German ReCreate Cluster) was also interviewed for the newspaper article. The title “Lausitz gives new life to old slabs” refers to the Lausitz region, where Cottbus is located and the BTU and ECOSOIL are based.
Both articles first present the sports clubhouse in Kolkwitz near Cottbus. In 2009, the building project was realized using used concrete elements. The used concrete elements were recovered from a prefabricated slab building from GDR times that was located in Cottbus. ECOSOIL was commissioned with both the deconstruction of the 8-story slab building and the construction of the new building. Prof. Mettke from BTU designed the construction project together with the future users and accompanied the implementation of the project scientifically with her team of employees. Based on the process recordings for the deconstruction and the reuse of the concrete elements, the savings in resources and greenhouse potential were calculated in comparison to a conventional design.
The (re)construction project serves the BTU and ECOSOIL as a reference for an implementation possibility and what is feasible, with concrete elements suitable for reuse. ECOSOIL has become the market leader in the careful element-oriented deconstruction of prefabricated buildings, while the BTU has become an initiator and consultation partner for (re-) construction projects.
In addition, Prof. Mettke and Axel Bretfeld (Managing Director of ECOSOIL) presented the ReCreate project and the European partnerships with the Finnish, Swedish and Dutch clusters. The goals and tasks of the project were outlined in the articles as well as an outlook on the planned German pilot project of a youth center in the city of Hohenmölsen.
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.
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.
At the site of the imposing Belem Cultural Center in Lisboa, we had our first review meeting with the ReCreate project advisor from the European Commission.
At the meeting, each work package leader had the opportunity to present their project achievements made in the past year and a half and to receive feedback from our project advisor Susaná Xara and Elena Granados Menéndez – the external expert architect assigned to the meeting.
Also, the ReCreate review meeting participants had the privilege to see the Terra exhibition at the Lisbon Architectural Triennale 2022, which, in their own words, looks into communities throughout the world that embrace our common home, planet Earth and how do resource depletion, socio-economic inequalities, and climate alter-actions intertwine at different scales. The exhibition is a call to action inspired by shared local insights from around the globe with the potential to transform the current fragmented linear system of cities-as-machines into a circular holistic model of cities-as-organisms.
We were proud to see that the ReCreate project was also part of the exhibition, which was presented to the consortium, as well as the wider architectural community by our own Erik Stenberg.
At the end, we managed to meet each other in person, which also granted us a greater opportunity to increase coordination and create stronger connections.
Leader of the ReCreate Swedish country cluster Erik Stenberg had another interview where he outlined the importance and advantages of the project.
The advantage of the concept is that the climate footprint and amounts of waste are radically reduced as it is much better to reuse entire elements than to grind down the concrete and use it as filling material, says Erik Stenberg.
THE STATE OF REUSING CONCRETE IN SWEDEN
Today, concrete elements are very rarely reused. At EU level, the figure is zero percent and in Sweden there are a few isolated examples. This is mainly because it is cheapest and easiest to build with new concrete. The business models for reuse do not exist and all parts of the construction sector are adapted to new materials, says Erik Stenberg. The goal of KTH researchers will be to examine the business chain for the reuse of concrete elements in the Swedish context and how it is affected by processes and regulations in the construction sector. Sweden actually has good conditions for reusing concrete elements because we built a lot with prefabricated concrete in the 1960s to 80s. Even if the elements are not manufactured to be taken apart and used again, according to Erik Stenberg, this is entirely possible.
ON THE SWEDISH PILOT SITE
The pavilion that the researchers built and displayed during H22 was a successful sub-project. The building consisted of 99 percent recycled material and the climate footprint had been reduced by 90 percent. The mistakes made gave the researchers new insights, for example that concrete must be handled carefully. The reuse also led to unexpected architectural solutions.
The elements were larger than we imagined, which resulted in a sturdier building. Solutions around doors and windows had to be adapted to this and the house’s pillars got a new design when they proved to be too heavy for the slab. Instead of being seen as obstacles, the limitations can contribute to interesting architecture, says Erik Stenberg.
Erik Stenberg also maintains a studio where students design buildings based on the concept in the research project. Erik Stenberg says that the students have shown that it is possible to design houses with good layouts and good light conditions from recycled concrete elements and that it is possible to design both row houses and point houses with elements from slatted houses.
Erik Stenberg, a lecturer in architecture at the KTH School of Architecture and leader of the Swedish ReCreate country cluster, investigates the current practices of the reuse of precast concrete in the world.
He posits that offices with prefabricated concrete structures are the most common buildings that are demolished today, most often for housing construction, and that concrete from those demolished buildings is simply ground and that we create an unnecessarily big impact on the environment by doing so.
”When recycling, the product is changed and used for something else, or in the same area of use. When we are reusing, it is used once more in the same form and design.”
– “I’m afraid that someone will think that, like in Denmark, we will start grinding programs worth millions. It would be capital destruction because the houses are built with quality and will last at least another 150-200 years if they are dry and warm.” said Erik Stenberg.
According to him, Denmark also failed to meet the goal of reusing building elements in projects, in order to incorporate a better local history for residents, because the EU directive is that at least 70 percent of a building’s weight must be reused during demolition. However, in the Swedish ReCreate pilot study, the figure dropped to a staggering 99 percent!
He concluded that there were some mistakes in the project, but now they know where the obstacles lie in the construction permit phase, how access and quality can be ensured, and how the concrete elements can be reassembled, which enables an immediate reduction of carbon dioxide in new production.
At the end of the summer, members of the German ReCreate cluster met with members of the Dutch cluster for a transnational technical exchange at a deconstruction site in the small town of Weißenfels near Leipzig in Germany. In consultation with the BTU project manager Angelika Mettke and the German industry project partner Dietmar Gottschling of ECOSOIL, the meeting was prepared on-site to show how partial dismantling is carried out under practical conditions.
The dismantling process was observed by Viktoria Arnold (BTU), Thijs Lambrects, Hamidullah Attaullah (both TU/e) as well as an employee of the office of Patrick Teuffel (head of WP5) at the location site, Hardenbergstr. 39-42. The demonstration allowed them the ability to gain an insight into the dismantling process directly on site.
Considering the process, the partial deconstruction comprised the top two floors of the 5-story prefabricated building of the “P-Halle” type, which was constructed from the same range of prefab elements as the donor building for the ReCreate German pilot project at Otto-Nuschke-Str. 9-14 in Hohenmölsen. Accordingly, the same range of slabs and panels had to be dismantled and the same connections opened. That resulted in 30 dismantled floor slabs which required transport from Weißenfels to Hohenmölsen, where the temporary storage site is located.
The dismantled floor slabs are planned to be (re)used later on the same site in the planned pilot project, the construction of a youth center. Concerning the remaining dismantled concrete elements, they had to be handled with more caution because of potential causes of material composition. By that means, they first had to undergo the process of pre-shredding at the dismantling construction site and then sent to a recycling plant for material processing.
Check out the pictures of the site below of the dismantling process at the deconstruction site: