News - Recreate

January 15, 2025

Arlind Dervishaj, KTH

Concrete is used everywhere—in buildings, cities, and infrastructures. However, due to the large quantities of concrete used worldwide, it contributes to around 8% of global CO2 emissions [1]. While efforts are being made to reduce its carbon footprint, such as by using supplementary cementitious materials, an often overlooked solution is reusing concrete.

The ReCreate project aims to foster a circular economy in the construction industry by reusing precast concrete elements from existing buildings in new construction projects. To support this goal, our study investigated the reuse potential of structural concrete elements, evaluating three key factors: the remaining lifespan of concrete, natural carbonation (ability to reabsorb CO2 over time), and embodied carbon savings achieved by reusing it [2]. Reusing concrete has multiple benefits as it prevents waste, reduces the need for new raw materials, and significantly lowers life cycle CO₂ emissions. However, it is not as straightforward as it looks. The structural integrity of concrete with reinforcing steel can be compromised over the lifetime of buildings, if the right conditions for corrosion emerge, such as from the carbonation of the concrete cover and the presence of moisture at the rebar interface [3].

Circular Construction concept for concrete

Based on established carbonation models, we proposed a digital approach for estimating the remaining service life of concrete elements. The digital workflow also estimates the CO2 uptake from natural carbonation. We tested the workflow on an apartment building with a precast concrete structure, built in Sweden in 1967 during the Million Program. The building was modelled digitally, and material quantities and exposed surface areas of concrete elements were automatically extracted.

Digital workflow and building model

A key aspect of the study was the comparison of carbonation rates specified in the European standard EN 16757:2022 with rates derived from measurements in the ReCreate project and the literature [4,5]. This comparison revealed that the carbonation rates in EN 16757 may be overly conservative and hinder the reuse of concrete elements. We argue that relying on contextual carbonation rates, such as the ones in our evaluation, from a previous condition assessment, and new on-site measurements, is crucial for making informed decisions about concrete reuse. The study also addresses the recent RILEM recommendation on revising carbonation rates in standards like EN 16757 and CEN/TR 17310:2019 [6].

Using carbonation rates from EN 16757:2022, led to the conclusion that most of the precast elements would not be reusable (i.e. carbonated concrete cover and past the initiation phase for service life). The standard assumes a high rate of carbonation for concrete, especially indoors, which reduced the concrete’s remaining service life; concrete cover for indoor elements was expected to carbonate the earliest, 23 years after initial construction. However, when using the contextual carbonation rates derived from the ReCreate project’s investigation and recent literature, all elements were deemed suitable for reuse, with sufficient remaining lifespan. Plaster and other coverings slowed carbonation significantly, extending the service life of concrete. Additionally, carbonated concrete elements can be reused, but further considerations should be made concerning the environment and exposure conditions in the new building. Recommendations from ongoing research in ReCreate are expected for concrete reuse in new buildings.

The study also assessed the CO2 uptake of concrete over its life cycle, including the first service life, a potential storage period prior to reuse, and a second service life when reusing precast elements. The findings indicate that the CO2 uptake estimated using the EN 16757 rates was significantly higher than the estimate based on contextual rates. Additionally, the study demonstrated that the climate benefits of reuse exceeded those of carbonation, which accounted for less than 6% compared to the emissions associated with the production and construction of new precast concrete buildings. This highlights the importance of prioritizing reuse as a key strategy for reducing the climate impact of buildings.

Furthermore, the study investigated the implications of three different allocation methods for assessing the embodied carbon of concrete over two life cycles. The analysis included scenarios with and without carbonation uptake. The results indicated that the Cut-Off method was the most advantageous for reusing the existing building stock, followed by the Distributed approach, while the End-of-Life approach was the least favorable. The study emphasizes that the reuse of existing building stock offers a substantial opportunity for mitigating climate change and fostering a circular built environment.

Comparison of three LCA allocations, over two life cycles

References

[1] Monteiro PJM, Miller SA, Horvath A. Towards sustainable concrete. Nat Mater 2017;16:698–9. https://doi.org/10.1038/nmat4930.

[2] Dervishaj A, Malmqvist T, Silfwerbrand J, Gudmundsson K. A digital workflow for assessing lifespan, carbonation, and embodied carbon of reusing concrete in buildings. Journal of Building Engineering 2024;96:110536. https://doi.org/10.1016/j.jobe.2024.110536.

[3] Angst U, Moro F, Geiker M, Kessler S, Beushausen H, Andrade C, et al. Corrosion of steel in carbonated concrete: mechanisms, practical experience, and research priorities – a critical review by RILEM TC 281-CCC. RILEM Technical Letters 2020;5:85–100. https://doi.org/10.21809/rilemtechlett.2020.127.

[4] European Committee for Standardization (CEN). Sustainability of construction works – Environmental product declarations – Product Category Rules for concrete and concrete elements (EN 16757:2022) 2022. https://www.sis.se/en/produkter/construction-materials-and-building/construction-materials/concrete-and-concrete-products/ss-en-167572022/ (accessed November 26, 2023).

[5] European Committee for Standardization (CEN). Carbonation and CO2 uptake in concrete (CEN/TR 17310:2019) 2019. https://www.sis.se/en/produkter/construction-materials-and-building/construction-materials/concrete-and-concrete-products/sis-centr-173102019/ (accessed September 26, 2022).

[6] Bernal SA, Dhandapani Y, Elakneswaran Y, Gluth GJG, Gruyaert E, Juenger MCG, et al. Report of RILEM TC 281-CCC: A critical review of the standardised testing methods to determine carbonation resistance of concrete. Mater Struct 2024;57:173. https://doi.org/10.1617/s11527-024-02424-9.

by ReCreate project

January 8, 2025

An essay on a circular design by the Principal of LIIKE Oy Arkkitehtistudio, Eric Rawlins.

I recently posted a graph on social media displaying the percentage of recycled material used in construction across EU member states. Finland places second but last, with only Romania reusing less material in construction. Reactions were astounding, ranging from questioning the graphs’ depiction to demands to clarify what are the materials in question at all, to claims that circularity is a fringe issue since it isn’t linear, to how spot on this finding is, and how high a mountain we have to climb.

Finns are pragmatic, focusing often – pardon the pun – on concrete solutions rather than philosophical debates. To paraphrase Mies van der Rohe, “getting things done” is crucial, whereas pondering is not quite so.

Albeit that the ReCreate project is focused on technology, the practice of “getting things done”, in this case how to integrate refurbished materials into a linear practice, might be considered less of an end. After all, even at its most utilitarian construction is always a means to another end. While construction processes are often viewed as self-orienting, there are ultimately merely an end to a larger purpose. Subsequently, buildings are designed by architects for the purpose at hand, less than the construction technique available.

This forces us to consider what exactly are we attempting to achieve with the buildings we build, and why is a particular purpose justified, particularly in a circular future. If by definition we are motivated by a low-carbon world and premised by the availability of reusable material(s), should we not consider how necessary construction is in the first place? And then which purposes, solutions and outcomes can be considered acceptable?

Anticipating these changes suggests a transformation where architecture evolves from a service to a deeply analytical and creative act, subscribing value, creating purpose, and resolving outcomes within material constraints. The need to transition to a circular economy emerges from a century of change, pushing us to move away from 20th-century models and technologies. To relinquish what was, in favour of what should be.

ReCreate already indicates that partners and stakeholders are becoming increasingly aware of reuse as a viable and realistic solution for a sustainable future. Not to perhaps entirely replace the linear world, but offer a complimentary path. As communities grow increasingly aware of the environmental impacts of post-war growth, the integration of reused materials in construction is beginning to show as a route to the future. One increasingly resonates with younger generations less inclined to believe in the world views of post-war extractive regimes.

This paradigm shift also suggests a reinvention of design, building, financing, and regulatory practices, presenting opportunities in fields beyond the construction sector. Where traditionally people see waste, we see the literal and conceptual foundation for a shift in societal values, business models and design practices. Reusing precast concrete elements might not represent a leap for mankind, but it does represent a significant step towards circularity in construction.

Our preparatory design studies navigate some of the constraints and possibilities presented by the selection of concrete elements and structures, retrieved from the Finnish deconstruction pilot. The emphasis is to study how to create an architectural solution to a given layout, which remains as faithful as possible to an original new build solution. Even in early studies, we have identified promising design strategies aimed to explicitly display the refurbished elements, as well as defined lines of study regarding potential hybrid structures, which may lead to real-life solutions that most likely would not be considered otherwise.

Our aim is to use the constraint-driven condition to establish an architectural language that will visibly express the ethos of reuse and sustainability, and encourage a dialogue between the old and the new, where our pilot building tells a story of continuity and renewal.

While it is said that history does not repeat, it merely rhymes, one is tempted to see similarities between today’s world and the world of the avant-garde. Transitioning to circularity is a phase change. If history is any measure, employing deconstructed material is a new practice which will manifest as a reinterpretation of architecture. Just as in the early 20^th century, societal and technological evolution manifested in the work of Le Corbusier, Mies van der Rohe and Alvar Aalto resulting in a new architecture as a concrete outcome, a societal construct and a value expression, it would only seem only logical to expect something similar from the Green Transition.

In this case the use of refurbished concrete represents more than a technical solution to environmental challenges—it becomes a manifesto for societal change, literally embodied in the structures we inhabit. By reevaluating how we build and what materials we use, we can instigate a profound shift in values, business practices, and architectural design.

Our take on circularity in construction is one where, respecting what we have, our maxim becomes: Function Adapts to Form. To quote Alvar Aalto:

“Nothing old is born again. But it doesn’t go away completely either. And what once was will always be again in a new form.”

Eric Rawlins

Architect

Principal

LIIKE Oy Arkkitehtistudio

Figure caption: Reusing building material from the existing stock is first and foremost an opportunity. (Photo: Tampere University / Heikki Vuorinen)

by ReCreate project

December 10, 2024

Leena-Aarikka-Stenroos-Mikko-Sairanen-Linnea-Harala-Lauri-Alkki_ReCreate-project_Horizon-2020-1280x670.png

As part of the ReCreate project, WP7 plays a pivotal role in developing circular business models for concrete reuse, contributing to the overall goal of establishing sustainable and economically viable practices in the construction industry. In this interview, key team members from Tampere University—Leena Aarikka-Stenroos, Mikko Sairanen, Linnea Harala, and Lauri Alkki—share updates on their progress, insights into co-creating business models, and the value propositions they’ve explored for expanding the reuse business across Europe.

Can you share some updates on what WP7 has achieved so far within the ReCreate project?

LEENA: Absolutely! We’ve hit two important milestones. First, we’ve mapped out how different countries approach the reuse of building materials, focusing on three specific cases. This has helped us understand how actors in the construction industry are involved in reusing concrete elements. Second, we’ve started developing business models that show how companies can profit from reusing concrete. Moving forward, we aim to keep refining our understanding of how these processes work across different countries to ensure the project’s success.

WP7 focuses on developing circular business models at both company and value chain levels. Can you explain how these business models are being co-created and how they contribute to the project’s goals?

MIKKO: We’ve created business model canvases to map out how companies can profitably reuse concrete. These canvases cover three levels: the overall system, individual company profiles, and specific process stages like quality control or storage. Different countries have slightly different setups. For instance, in Germany and the Netherlands, some companies manage most process stages from deconstruction to reconstruction, while in other countries, multiple companies handle different parts of the process. By analyzing and mapping these models, we help companies figure out how to make this approach profitable, both in the short and long term.

LEENA: I’d like to add that we’ve noticed a lot of variation in how these models work across different countries. Some companies only handle deconstruction, while others do both deconstruction and reconstruction, which affects their business approach. This diversity helps us understand how different roles and processes can be profitable.

Could you share some insights into the value propositions, value creation, and value capture strategies explored within WP7 for concrete reuse?

LINNEA: We found several ways that reusing building components can create value, either through cost savings or new revenue. Key factors include the design and condition of the donor building, location, logistics, and efficient project management. Regulations and industry acceptance of circular practices also play a big role in creating value.

LAURI: In the Netherlands, we saw that “one-on-one” reuse, where components are taken from one building and directly used in another, is the most profitable approach at the moment, but of course it requires a key actor who can take responsibility along the process from deconstruction to construction. Overall, in all pilot projects companies also gained new skills, especially in deconstruction and design, which are critical to enabling component reuse.

MIKKO: In Finland, making concrete reuse profitable is a challenge, especially due to high deconstruction labour costs. Success depends on strong regulations, efficient demand management, and clear strategies for reuse. The Netherlands and Germany are good examples of how to do this effectively.

LEENA: Learning is key. Companies may face higher costs at first, but as they gain experience in deconstruction and reuse, they become faster and more efficient, lowering costs in the long run.

One of WP7’s objectives is to identify strategies to expand the reuse business across Europe. Can you explain these strategies and how they deal with the local nature of the building industry?

LINNEA: We’ve considered the idea of creating a marketplace for concrete elements, which could help expand reuse. However, there are challenges in making this work locally and deciding who would manage and profit from it.

LEENA: Construction companies often work in different countries, and they can apply what they learn in one place to another. For example, a Finnish company in our project wants to use its new practices across all the countries they operate in. However, different countries interpret regulations differently, which can be a challenge.

LAURI: That’s a great point, especially since we have large companies like Skanska and Ramboll in the project. Sharing knowledge between countries is key, and some countries offer great examples for others to learn from.

How does the analysis of safety and health aspects translate into economic value within the concrete reuse ecosystem, and what measures are being considered to enhance safety and health in this context?

LEENA: Safety and health analysis is crucial but incurs costs, such as for quality checks and safe practices. We need efficient ways to integrate these assessments, potentially using digital technologies, to minimize expenses while ensuring safety, which is vital for economic value in concrete reuse.

LAURI: In our discussions with Skanska, safety concerns about reused concrete elements were prominent. It’s essential to communicate to customers that these elements are thoroughly tested and safe to build trust in the market.MIKKO: Brand reputation in construction hinges on safety and quality. Companies must meet these expectations to protect their image, making quality a critical aspect of our analysis.

LINNEA: Work safety regulations can vary, affecting project costs and feasibility. For instance, Germany has stricter safety standards compared to Finland, impacting deconstruction costs.

Can you elaborate on the connections between social and legal barriers and economic value within the concrete reuse business models?

MIKKO: Social challenges, like public trust in reused concrete, can influence demand and economic value. Legal barriers, such as product compliance and market access issues, also affect economic viability. Balancing these factors is essential for successful business models.

LEENA: The Finnish Ministry of Environment values expertise in creating supportive regulations for circular processes, aligning with our project’s goals to shape favourable EU and national legislation for component reuse.

LAURI: In Finland, there’s confusion over classifying deconstructed elements as waste or not, which complicates handling and permits. This uncertainty has caused delays in the pilot project.

LINNEA: Ownership of elements is vital; in Finland, construction companies retain ownership from harvesting to sale, simplifying the process.

How do you envision the role of technology, societal acceptance, and regulatory factors in shaping the economic aspects of concrete reuse, as discussed in Task 7.4?

LEENA: Technology, societal acceptance, and regulatory factors are interconnected in influencing concrete reuse economics. Advancements like automation and digital modelling enhance feasibility and efficiency. Societal trust in reused materials boosts demand, while balanced regulations are needed to support innovation without hindering business. Effective communication and marketing can foster societal acceptance, helping to increase demand for reused concrete elements.

WP7 focuses on identifying easily achievable improvements and economic benefits in concrete reuse. What are some of the “low-hanging fruits” that have been identified, and how can they accelerate the transition toward more sustainable building construction?

LEENA: We’re identifying simple improvements, or “low-hanging fruits”, that can promote concrete reuse. While still gathering data, we see that small changes can encourage companies to embrace reuse without a complete overhaul.

LAURI: A key improvement involves rethinking collaboration roles in construction. Embracing broader collaboration beyond traditional roles can significantly enhance concrete reuse efforts.

MIKKO: Effective data management and communication among all parties are crucial. Knowing where deconstructed elements will be reused and planning accordingly can optimize the entire process.

In your journey with the ReCreate project, could you share a memorable experience or moment that has had a significant impact on your perspective or approach to sustainable construction and circular economy initiatives?

LINNEA: As a doctoral researcher, my most impactful experience was visiting the German cluster, where I saw how cost-effective building component reuse transformed old elements into new spaces. It was enlightening.

LEENA: A key moment for me was realizing the potential of concrete reuse in reducing emissions and seeing the project’s problem-solving spirit that drives sustainable improvements.

MIKKO: Visiting Lagemaat in the Netherlands was eye-opening; seeing their profitable concrete reuse operations changed my perspective on feasibility in this area.

LAURI: My memorable moments include witnessing the Lagemaat operations and the progress of our Finnish pilot project, both highlighting the project’s impact.

In summary, WP7’s efforts within the ReCreate project are forging a path toward a more sustainable and economically viable construction industry through the development of circular business models for concrete reuse. The insights gained from diverse country analyses, coupled with innovative strategies for collaboration and technology integration, underscore the potential for significant advancements in this field. By addressing safety, social acceptance, and regulatory challenges, the team is not only enhancing the viability of reused concrete but also building a robust framework for future circular practices. As these initiatives continue to evolve, they hold the promise of transforming the construction landscape across Europe, making it more resilient and environmentally responsible.

by ReCreate project

December 6, 2024

The Dutch Concrete Event 2024 brought together leading professionals, agencies, and institutions from the concrete industry to share insights, discuss challenges, and explore innovative solutions. This annual gathering offers an invaluable platform to stay updated on repair, reinforcement, sustainable materials, climate impact, and regulatory advancements.

This year, TNO contributed to the event by presenting the latest developments from the ReCreate project. Marcel Vullings delivered an engaging presentation focusing on the practical application of reused precast concrete elements in new building structures. His talk was particularly relevant for designers and structural engineers, addressing key challenges in reusing structural components and discussing strategies to overcome them.

The session sparked a lively discussion about the need for protocols, regulations, and incentives to encourage reuse. Key questions were raised:

Could environmental taxes accelerate the adoption of reused materials?
Would subsidies provide a more effective boost to integrating reused elements into mainstream construction?

Despite these challenges, one clear takeaway emerged: reuse is no longer an exception. Increasingly, new projects incorporate reused precast elements, signaling a shift towards making this practice standard in the construction industry. Marcel emphasized how initiatives like ReCreate, combined with ongoing research by TNO, are instrumental in addressing remaining hurdles and driving innovation.

Events like the Dutch Concrete Event play a pivotal role in advancing this movement, bringing together diverse stakeholders to share knowledge and foster collaboration. They also serve to inform the market about cutting-edge developments, paving the way for a future where reuse becomes a core principle in construction practices.

by ReCreate project

November 22, 2024

Jakob Fischer, Brandenburg University of Technology

As Europe strives to meet its sustainability targets, the construction industry’s environmental impact is under increasing scrutiny. The sector is responsible for a significant portion of Europe’s resource consumption and waste generation. A key solution lies in evaluating building stock for its potential to contribute to circular economy practices, particularly through the reuse of construction materials like prefabricated concrete components. By reducing waste and conserving resources, this approach can help achieve the European Union’s (EU) climate and sustainability goals.

Europe’s Sustainability Goals and the Construction Industry

The European Union has committed to several ambitious targets, primarily through the Sustainable Development Goals (SDGs), including Goal 9 (Industry, Innovation, and Infrastructure), Goal 11 (Sustainable Cities and Communities), and Goal 13 (Climate Action). These goals promote building resilient infrastructure, reducing waste in urban environments, and taking urgent action on climate change.

In parallel, European policies such as the Circular Economy Package, the EU Waste Hierarchy, and the European Green Deal aim to curb resource extraction and promote material reuse. The building construction industry, as one of the largest consumers of resources and generators of waste, is central to these efforts. By recovering reusable concrete elements from existing structures, the sector can reduce its carbon footprint and contribute to Europe’s climate neutrality goal by 2050. The ReCreate project is developing numerous implementations to achieve these contribution goals.

Assessing Building Stock for Reuse

Evaluating building stock involves analyzing existing structures to identify materials that can be reused in new construction projects. This is especially important as Europe’s built environment contains vast amounts of materials, particularly concrete, that can be repurposed instead of discarded. The work package 1 of the ReCreate project is developing an analysis and mapping of existing precast concrete systems and elements.

Prefabricated concrete components, which are common in many buildings, offer substantial potential for reuse. These modular elements can be removed, inspected, and repurposed in new projects, reducing the need for energy-intensive production of new materials. Since concrete production is responsible for a large share of carbon emissions, reusing elements as a whole can significantly lower the environmental impact of the construction industry. Emission reductions of up to 98 % in comparison to virgin material prefabricated concrete elements, can be saved by reusing existing elements.

Urban Mining and the Circular Economy

Urban mining is a key element in transitioning towards a circular economy, where resources are reused rather than discarded. Buildings, especially those built in the mid-20th century, contain prefabricated concrete components that are still in good condition and suitable for reuse. Rather than allowing these materials to become waste, urban mining enables their recovery, helping reduce construction and demolition waste (C&DW).

C&DW represents nearly 40% of the total waste produced in the EU, underscoring the pressing need for robust waste management strategies. By reusing concrete elements as a whole the construction industry can contribute to a significant reduction in CO2 emissions. With concrete production accounting for up to 8% of global carbon emissions, any reduction in its demand has a meaningful impact on climate change mitigation.

Overcoming Challenges in Building Stock Evaluation

While the reuse of building components offers significant sustainability benefits, several challenges remain. On the one hand the structural and architectural integrity of reusable concrete elements have been testified and is being proven within the ReCereate project, however no market for reused elements has been developed yet, which could satisfy the demand of sustainable re-construction. Hence, the working packages 1 and 6 with the deliverable 6.2 will give an overview of the distribution and amount of defined elements in the existing building stock.

Another challenge is to evaluate the needed information for exact types of elements in existing buildings from national building stock databases. With the support of building owners (e.g. providing information on their building stock), reviewing literature and archives on construction/production activities in the past and assessing the current and future demolition rate, a more accurate assessment of the building stock will be investigated.

A centralized database tracking reusable materials across Europe could further enhance urban mining efforts. By cataloging the types, quantities, and conditions of reusable components, such a system would allow construction companies to plan projects more efficiently, ensuring that recovered materials are utilized effectively. Parts of these efforts will be achieved within ReCreate.

Conclusion

The systematic evaluation of building stock and the adoption of urban mining practices can contribute significantly to Europe’s sustainability efforts. Reusing materials like concrete supports SDG 9 by promoting resource-efficient infrastructure. It also aligns with SDG 11 by reducing urban waste and improving resource management, while contributing to SDG 13 by helping reduce the carbon emissions associated with new construction.

Achieving this requires collaboration between policymakers, industry professionals, and researchers. Governments can implement the regulatory frameworks and incentives needed to make reuse the norm, while construction professionals must adopt new approaches that prioritize resource recovery. Also building owners should be sensitized, to regularly evaluate their building stock, keeping track of their own ‘urban mine’ and step forward to interested planners and stakeholder in the construction industry with their upcoming potential of deconstructable and reusable concrete elements.

The future of Europe’s construction industry is circular, and evaluating building stock is a key step in realizing this transformation.

by ReCreate project

October 18, 2024

Arnaldur Bragi Jakobsson

Second Wind explores the potential of reusing pre-cast concrete elements from an obsolete apartment building in Helsingborg, Skåne County, Sweden.

As part of the ReCreate initiative, which encourages the sustainable repurposing of concrete components, I collaborated with Helsingborgshem, the city’s municipal housing company, to develop a new rowhouse typology of approximately 100 m², alongside a two-story multifamily apartment building on the same plot.
The project aimed to minimize modifications to the existing structural components, preserving their original form as much as possible while adapting them to new uses. The rowhouses, arranged in an L-shape with a southwest-facing courtyard, serve as rental units and highlight the potential of reused materials in creating modern, functional spaces. The apartment buildings, located on the north and south sides of the site, further demonstrate the versatility of these repurposed elements.

Throughout this process, I sought to maintain a connection to the original architectural context of the Drottninghög area, respecting its mid-20th-century character while introducing new, sustainable housing solutions. This project illustrates the significant environmental benefits and creative opportunities in reusing existing building materials, paving the way for more sustainable construction practices.

Rowhouse plan (Arnaldur Bragi Jakobsson)

by ReCreate project

September 27, 2024

Written by Linnea Harala & Lauri Alkki

The ReCreate pilot projects in Finland, Sweden, Germany and the Netherlands highlight diverse approaches to implementing concrete element reuse, each influenced by unique building types, contexts and organizational structures. An initial analysis by ReCreate’s business research work package (WP7) has revealed distinct patterns in these approaches, primarily categorized into centralized and decentralized models. During the ReCreate annual meeting in Zagreb, WP7 also organized a workshop to present the identified approaches to other project partners and to get feedback on the initial analysis.

Figure 1 & 2. Workshop between ReCreate partners at the annual meeting in Zagreb on the preliminary results of the two different approaches.

The identified approaches – A) centralized & B) decentralized

The centralized approach is characterized by a single key actor managing multiple phases of deconstruction and reuse. This model is most prominent in the Netherlands. There, the same actor is responsible for deconstructing a building and reusing most of its elements in a new structure, a process referred to as 1-on-1 reuse. The ecosystem in a centralized model is simple, with a central hub managing all operations. The key actor controls the flow of information and data mostly internally, ensuring streamlined communication and decision-making. In addition, the key actor’s business model extends to both deconstruction and reuse, highlighting its capabilities and resources. A strong single actor can oversee the entire project, facilitating optimized and controlled execution. With one key actor at the helm, there is a clearer distribution of tasks and responsibilities. On the other hand, success depends heavily on the performance and capabilities of the key actor.

Conversely, the decentralized approach involves multiple specialized actors managing different phases of deconstruction and reuse. This model is evident in Finland and Sweden, where elements are harvested and reused in various buildings. The ecosystem in the decentralized approach consists of several specialized, complementary companies and organizations. Therefore, effective communication and data sharing between these actors has been identified as a critical factor for success. In the decentralized approach, each actor operates based on its expertise and specialization, contributing to a more diversified and flexible business landscape. The feasibility of the decentralized model depends on how well the project organization coordinates multiple companies. This complexity requires robust inter-organizational collaboration to ensure smooth transitions between phases, as multiple actors require more discussion to define responsibilities at different stages, at least initially.

Overall, it can be seen that in the centralized approach, the control of the dominant key actor can streamline operations, but it relies heavily on this actor’s capabilities. On the other hand, the decentralized approach, while more complex, offers flexibility and the potential to leverage a wider range of expertise. In both approaches, the work phases and tasks are largely the same, but their overlap and sequence may vary. Ultimately, understanding these approaches allows for better strategic decisions throughout the concrete element reuse process, promoting more sustainable and efficient construction practices.

by ReCreate project

September 6, 2024

ReCreate representatives from Sweden, Erik Stenberg and Helena Westerlind, project coordinator from Finland, Satu Huuhka, and Eetu Lehmusvaara (TAU) are preparing to exhibit the project in the Tallin Architecture Biennale 2024.

Description taken from the official website of the exhibition:

“7th Tallinn Architecture Biennale (TAB) will be titled “RESOURCES FOR A FUTURE” and curated by Anhelina L. Starkova, Kharkiv; Daniel A. Walser, Zürich; and Jaan Kuusemets, Tallinn.

TAB 2024 will be held in October – November 2024.

Architecture needs to play a key role in future change. Hereby resources are one of the main factors in the future development of our planet. TAB 2024 explores architecture and urban planning from the perspective of resources. The exhibition will focus on different parameters of resources such as building materials, typologies, orientation, and architecture to the level of urban planning and society. The exhibition will have a world-wide perspective with a local base and call for action.

After Sustainability: Architecture Remains

Escalated global tensions imposed new tasks on architecture, where architects are left with a reduced amount of resources for the creation of social mobility, diversification, and changeability as the usual parameters of conceiving architecture. What approach must we take in such a setting? The mass architecture will not disappear, but it needs to accept the resources available to it. Access to quality in architecture should not be limited to a fortunate minority. To sustain social cohesion, we have to create environmental opportunities for everyone. Architecture serves beyond aesthetic purposes; it’s a powerful transforming tool that creates social life, but for that, we have to raise the building profession by moving it into the architecture of the unseen, unpleasant and hidden.

How to conceive and construct an architectural program that remains stabilising enough to support architecture amidst ever-changing environmental conditions in perpetual crisis?

We are facing a challenge to operate within unsustainable and prevailing conditions that need to be converted into resources for the future development of society. Utilising local resources would reinforce existing structures and facilitate the transformation towards improvement and progress. Defensiveness and reusefulness will be the basis of future construction in architecture. Buildings need to be in use for a much longer time, despite our economically driven lifestyle.”

More about the exhibition here.

by ReCreate project

August 30, 2024

Lina Brülls, Graduate Architect and Master’s Student in the Computer Science Program at Chalmers University of Technology

The master’s thesis “Resource-Driven Design” explores how the design process can be adapted to facilitate the reuse of structural concrete elements. Research done in the thesis indicates that current design and data processes are not easily translatable to reuse scenarios, where preexisting structural and geometrical attributes of materials must be considered. Based on this, three key research questions are formulated: identifying the necessary data for the reuse design process, developing a Grasshopper Rhino plugin for data integration, and applying this tool in case projects with the aim of optimising reuse.

The developed Grasshopper plugin, programmed in C#, enables data handling from Excel into Rhino. It generates structural modules from reused hollow-core and load-bearing wall elements based on desired design parameters. The tool was tested in three architectural projects on Siriusgatan in Bergsjön. Regular consultations with the ReCreate team at KTH provided helpful expertise and feedback throughout the development process.

The study’s findings suggest that integrating data early in the design process can improve the efficiency and feasibility of reusing structural elements. One key challenge encountered in this project was planning within the constraints of the generated load-bearing modules. Including glulam beams introduced necessary flexibility, enabling adjustments in level height and allowing the removal of some load-bearing wall elements.

by ReCreate project

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.

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