ReCreate project, Author at Recreate

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

March 15, 2024

Inari Weijo, business development manager (refurbishment), Ramboll Finland

During my master’s thesis work over 15 years ago, I familiarised myself with precast production and its history in Finland. After that, precast concrete has been playing a role in one way or another in my work career. Many projects have involved either repairing precast concrete buildings or building new ones. Since the 1970’s, precast concrete production has formed a significant part of the Finnish construction sector. The systematic and ‘simple’ method provided a standardized way to build, and it quickly became very widespread. The precast concrete system has been criticized for producing a unified stock of buildings, reducing versatility in urban environment and suppressing designers’ creativity. Since the early days, though, the technique spread to erecting ever more complex and monumental buildings. It has been foundational for providing a fast and trusted way for building construction in Finland. There are thousands and thousands of precast concrete buildings here, and some of them are already slated for demolition. A part of the buildings suffers from degradation, but many are just mislocated from today’s point of view.

Figure 1. Finnish deconstruction pilot in Tampere, building vacated before the deconstruction of elements for reuse.

I believe that technical know-how is essential for creativity and enables responsible and sustainable construction. We must be more aware of our decisions’ environmental impacts when building new. Architects’ and engineers’ creativity is ever more challenged as we must prioritize sustainability values. Knowing the technical limitations and possibilities is crucial, so that creativity can be unleashed in the right place at the right time, and adverse uncertainties can be eliminated. Building new is inevitable in the future too, but we need to redefine ‘new’. We must apply regenerative thinking, create net positive solutions and aim for more ambitious circularity. The actions we undertake should have a positive impact on nature and the environment so that instead of consuming it, they restore and revive it. This is a leading value for Ramboll.

Figure 2. Regenerative approach to construction. Image source: Ramboll.

The prevalence of precast technology and the aim for a regenerative effect on environment are two leading thoughts that that drive our ambition here at Ramboll to examine and challenge the present business as usual in the construction sector. The headline’s statement inspires me and my colleagues at Ramboll Finland when we seek to find alternative ways to utilize what already exists. The built environment is a bank of building parts that has technically perfectly fine components stocked in it, preserved intact inside buildings. Only processes and systems to utilize them effectively are needed. I sometimes face people itemising reasons and obstacles why reusing building parts is way too difficult. I believe this pessimistic attitude may well up from the insecurity that follows from the building sector changing dramatically. There may also be a disbelief whether the huge leap, which is necessary, can be taken. Some of the items that the sceptics list are well known, some are relevant, and some are just fictional. We need to keep solving them one by one, showcasing with real-life projects that this is possible and acquire more experience to narrow down the gaping hole between the ‘old’ and the ‘new’ way of building.

An important milestone has been reached when the Finnish cluster finished the deconstruction of the pilot building in Tampere this autumn. We succeeded to reclaim several hundred hollow-core slabs, columns and beams intact, ready for use on next building site. It’s been encouraging to gain good test results, both before deconstruction, through a condition investigation, and after deconstruction, as some of the deconstructed elements have been load tested. All has been well from an engineer’s perspective! Now, the reclaimed building parts are being fitted into prospective new building projects. The search for the new building site has not been stalled because of any technical issues but rather by the currently poor market situation.

That final issue to solve – an important one indeed – is the business model that can support reuse. A circular business needs more collaboration among all the players in the field. Technically we are ready to say ‘yes’ to reusing precast concrete elements!

Figure 3. Reclaimed hollow-core slab, deconstructed from the donor building in Tampere.

by ReCreate project

February 28, 2024

José Hernández Vargas

Architect and PhD student at KTH Royal Institute of Technology

A precondition for reusing precast elements is a correct understanding of the underlying logic of different building systems and the structural interactions between concrete elements. The analysis of existing precast systems starts with a thorough examination across multiple scales, as building layouts, individual elements and their connections are interdependent.

During ReCreate, several precast concrete systems have been identified and studied. While specific pre-demolition auditing and quality control are critical steps towards reusing concrete elements, this ordering of precast elements operates at an earlier and more abstract level, providing a knowledge base for known precast systems that may apply to multiple instances. This task attempts to provide an overview and develop guidelines for the further classification and digitalisation of precast elements as potential material for reuse. Moreover, the information gathered can serve as methodological guidelines for other systems that may differ from the studied cases but follow the same core principles.

When examining technical drawings from historical precast systems it is important to identify patterns that reveal the systematic ordering of the elements. This initial step involves identifying the underlying measurement system from the axes of the building, from which standard layouts can be inferred in discrete modules. Strict repetition patterns can often be found, especially in residential buildings, where building blocks are constituted by the repetition of a building module defined by a staircase. Similarly, this building module can be divided into residential units corresponding to the individual flats on each floor. Each unit defines in turn a defined arrangement of precast elements that can be precisely estimated for each building.

Thus, architectural and structural knowledge of precast buildings is essential for accurately estimating the building stock and potential for reuse of precast buildings. Given the economies of scale involved in this kind of building, the goal of this step is to build a knowledge base to establish workflows for the ordering and analysis of potential donor buildings for reuse.

Building scale

At the building scale, the analysis centres on the identification and classification of precast structures by structural principles and different building types. Precast buildings can be found in all sorts of applications. Yet, despite the wide range of structural solutions they predominantly follow a limited set of basic structural systems. The most prevalent structural frameworks for precast concrete include the portal-frame, skeletal structures, and wall-frame structures. Structural systems for arranging precast structural systems are closely linked to the building types they serve, responding to the intended program’s requirements. For example, portal-frame structures are most suitable for industrial buildings that require large open spaces. Conversely, for residential buildings wall-frame structures are more often the most cost-effective solution as load-bearing walls also separate living spaces. Beyond buildings completely built out of precast components, specialised subsystems can be found for facades, floors and roofs in combination with other structural systems.

System Skarne 66 (Sweden) and their main structural components form the original technical drawings (left) and as a digital 3D model (right)

Component scale

At the scale of individual precast elements, the foremost classification derives from grouping them by their structural role in the structure, i.e., as walls, columns, slabs, roofs, beams, foundations, and stairs that constitute the structure of the building. These categories are based on the Industry Foundation Classes (IFC) Standard (ISO16739-1), which provides a consistent framework for describing elements within the construction industry. These groups can be understood and modelled as variations of the same parametric object, akin to a family of building components. This process is key for building a comprehensive database of precast elements contained in each building.

To further understand the arrangement of elements that constitute a system, the overall dimensions of each element can be plotted to reveal the dispersion of distinct types within the system. In this example, all the elements are aligned in Cartesian space to define the largest dimension on each axis. This method allows the creation of a ‘fingerprint’ of each building, that shows a concise overview of the dispersion of element types and the individual quantities involved. Alignments resulting from common features such as floor heights and standard modules, can also be observed.

Comparison of the ‘fingerprint’ tool showing the types of elements used in System Skarne 66 (Sweden) and BES (Finland). Dot size indicates the number of elements of each type whereas colour corresponds to the main component categories.

Connector scale

At the connector scale, the different relationships between concrete elements can be related to force transfers and security features to ensure the correct and reliable transmission of forces. Connectors are key to ensuring structural integrity by managing structural loads while accommodating additional stresses and strains that arise from thermal movements, residual loads, seismic loads, and fire exposure, among others. A key aspect for evaluating the connectors is the assessment of the alternatives for disassembly and possibly reusing the connector. Analysing precast buildings at the connector scale allows the identification of the compatibility of precast elements across multiple systems from the analysis and comparison of structural details.

Ordering precast systems across these three scales provides a comprehensive picture of how precast systems are conceived, manufactured, and assembled. This knowledge is instrumental for understanding the possibilities that these elements offer for the next building lifecycle. This ordering will serve as the basis for classifying different precast systems into taxonomies and for the digitalisation of existing precast stocks as material for reuse in future projects.

by ReCreate project

January 31, 2024

Toni Tuomola, District Manager, Skanska (Finland)

Skanska’s role in ReCreate is strongly linked to its goal of building a better society. Being climate-smart – one of our sustainability themes – supports the achievement of this goal. Within the ReCreate project, we are studying how to produce low-carbon solutions through our business operations. ReCreate will provide us with information on how the circular economy of building elements could be promoted in the future – for example, in the planning phases of construction projects. We can have a major influence over the carbon footprint of a project’s outcome, especially in in-house development projects and, above all, in projects where we are responsible for the design.

ReCreate’s Finnish deconstruction pilot site is a 1980s office building in the city of Tampere. The precast concrete frame has been dismantled using a new technique developed and studied as part of the project. Construction projects are complex entities that demand close cooperation to meet targets. We have already worked with the ReCreate project partners for a couple of years on studies and advance preparations to facilitate the practical deconstruction work. Thanks to the studies, we were capable of dismantling the precast concrete elements intact for reuse. We also know how to verify the properties of reusable elements reliably and cost-effectively.

The possibility of technical implementation alone is not enough

Creating a business ecosystem for reusing building elements is an important part of the project. Reuse requires off-site production plants for factory refurbishment and the creation of an entire logistics chain and information management process to put the elements to use again. A marketplace is also needed to bring product providers and users together. Barriers must be lowered in building regulations and practices, and operating models must be harmonized.

What are the implications if reuse is successful? Firstly, the environmental benefits will be significant because the carbon footprint of reused concrete elements is about 95% smaller than that of corresponding new elements. Therefore, it will be possible to realize a substantial decrease in the carbon footprint of new buildings. Reused elements may not necessarily be used to construct entire buildings, but they would be utilized in the most suitable places. This would ensure that the dimensional and strength properties of reused elements can be used to the best effect.

The reduction in the carbon footprint helps us to meet the low-carbon requirements that will be introduced through regulation in the future. Environmental certification programs such as LEED and BREEAM also award extra points for reusing building materials.

Decommissioning a building by deconstructing elements is slower and more expensive than conventional destructive demolition. However, prior international research has found that a reused element can be as little as 30% of the price of a new element. This is an important perspective for projects researching business opportunities based on the circular economy.

A climate-neutral society is the sum of many parts, large and small. The circular economy of precast concrete elements is one factor among many. We need all the parts to work together to reach this goal.

by ReCreate project

December 13, 2023

Christoph Henschel, BTU

In conventional architectural projects, the use of the building and the design concept typically determine the dimensions of the structure. This means that the height of spaces, as well as the width and length of rooms, are defined by what will happen in them once they are built. Constraints on the size of a building are usually only imposed by limited budgets, the site and its context, or zoning laws. All of this changes drastically when reused precast concrete comes into play. Suddenly, the structure dictates the spatial dimensions, the grid size or the floor heights of the building design. This changes the design task for the architect and presents new challenges. In order to show that these challenges are also full of opportunities, the following text describes the design process for the German pilot project within the ReCreate project, a youth center for the town of Hohenmölsen.

The design task began with a detailed analysis of the elements that could be salvaged from the donor building. Specific types, dimensions and available quantities of exterior and interior walls and ceiling slabs were determined. Preliminary tests of the concrete strength and examination of the reinforcement properties ensured the suitability for reuse in advance. With this catalogue of elements as a starting point, the design process for the new building could begin – always with the goal of using as many reused elements and as little new material as possible.