In integrative building design, interaction among all building disciplines and stakeholders is sought from the earliest development phases, aiming to achieve optimal solutions through iterative and lean approaches.
The quest for energy efficiency is a key component in this systematic methodology, intending to minimise the burden that construction imposes on the environment, while promoting positive effects, such as a healthy indoor environment, positive social interactions, and maintained or increased value of materials (Mulhall, Braungart, Hansen 2019).
The way building materials or building elements are chosen, produced, conditioned, assembled, modified and handled at the end of use cycles, are crucial issues within this integrated approach.
These issues require a systemic change from linear to circular cycles so that the building sector may develop according to the limited capacity of the environment and to the natural resources available.
This challenge was tackled in various ways by the Buildings as Materials Banks (BAMB) project that was previously discussed in a BUILD UP overview article. This article covered the general structure and principles of the project, its main components, perspectives, and hurdles in the mission of transitioning to a circular building sector in line with the UN 2030 Agenda for Sustainable Development.
The BAMB project ended in February 2019 and was marked by an Industry Day Conference and two Academic Days. These were part of the SBE19 international conferences series, and held at the passive building HQ of the project coordinator, Brussels Environment. Several outcome reports and publications have been issued following this closing event, and added to the project’s library.
These set out the conclusions and lessons learnt from the different working groups and focus areas that were tackled by the consortium of 15 European partners, together with academic, professional and industry stakeholders gathering around a fruitful collaboration.
This article aims to comment on some highlights from the Conference and on the “4 Pilots Built + Feedback report”, bringing to light concrete experiences from the BAMB project.
SBE19 Final Conference BAMB-CIRCPATH: A Pathway for a Circular Future
The opening keynote speaker of the Industry Day, J. Drinkwater (WGBC Europe), stressed the importance of the key role of a circular building industry amongst several of the 17 UN Sustainable Development Goals, and set out what the road to having all buildings operating at ‘net zero carbon’ in 2050 looks like.
Europe has a leading position within this global challenge, where CO2 emissions need to be addressed urgently across the full life cycle (Embodied Carbon Review). Achieving the Paris Agreement depends on the shift in this debate, and the Europe-level framework and common language for assessing building sustainability performance “can be the foundations of future building sector policy in the EU and help establish a world leading approach to circular and life cycle thinking”.
The Industry Day was structured in 6 thematic parallel sessions; (1) how it is Making the Right Decision for Circularity with the BAMB approach and tools, (2) How can we collaborate to empower the development of materials passports?, and (3) Reversible building design tools, opening the door to circular construction, were explained by Elma Durmisevic (U. Twente and 4D Architects). VITO members (Smeets, and Wang) showed how it can be done in (4) Turning BAMB solutions into value for your business. Two more sessions also covered (5) Policy Recommendations – supporting the sector through policy in order to make circularity business as usual, and finally (6) learning by doing – circular architecture tested at real scale, covering the BAMB pilot-projects experience.
After collecting feedback from thematic sessions and the presentation about Reburg: world’s-most-circular-city! by Wim Debacker (VITO), former EU Commissioner for the Environment, Janez Potočnik (Co-chair UNEP International Resource Panel IRP) concluded the event.
He stressed that we do not have “the luxury of thinking and acting based on short term logic and interest”. Mr. Potočnik explained how the Circular Economy is part of the overarching societal and cultural transformation needed to “sustain humanity and its prosperity”. He developed examples of transformation leads and the unique opportunity we have now to shift “the expected urbanization onto a more environmentally sustainable and socially just path”.
His recommendations ranged from Urban Metabolism actions to concrete Pathways of Change for business and planning, to Governance Measures. Risk management and the understanding of responsibilities needs to comply with the Sustainable Development Goals through collaborative and systemic approaches.
Over the following two Research Days, the Scientific Committee retained 76 scientific papers, out of 120 received.
The Organising Committee, led by Professor Luís Bragança (University of Minho), structured the presentations around 7 topics;
(1) Management tools and supportive mechanisms for circular applications and business models, (2) Strategies, tools and systems to promote circular economy in buildings, (3) Design for adaptability, reconfiguration and high reuse potential, (4) Environmental assessment and economic impacts for measuring circularity, (5) Efficient waste and resources management, (6) Barriers and opportunities for a circular built environment, and (7) BIM and digitalisation towards high reuse potential and the circular economy.
Architectural case studies are emerging from reclaimed materials, mechanical automation to separate mortar from bricks at an industrial scale, renovation approaches and strategies, geo-localisation and mapping platforms for inventory of materials in urban contexts, embodied energy calculation for optimal interventions, and innovative procurement and business models.
These are some examples of the interesting and complementary contributions that reflect innovative research and best practices on current issues in the field of circular building and the construction industry.
Reversible Design Competition
On behalf of BAMB’s consortium, the University of Minho also organised the Reversible Design Competition, aiming to shed light among young generations of students of engineering and architecture of circular economy concepts and opportunities in the building sector. Students were invited to use BAMB’s materials passport platform and BAMB’s reversible design guidelines and protocol, in order to present innovative designs for buildings that are flexible and adaptive over time.
The transformation capacity of the buildings was intended to embrace alternative functions of commercial, residential and services use.
Eighty-four proposals from twenty-three countries were received, and the jury reported a challenging task to decide among so many high-quality projects. The three awards, granted at the closing of the Final Event all went to teams from the Manchester School of Architecture.
First prize went to the Flexi-SpACE proposal from Joseph Shenton, Khe Lyn and Gabriel Wyderkiewicz for developing a completely modular, cubic system growing from a core building, serving scalable structural units enveloped by a flexible façade system.
The whole concept paid attention to simple and reversible connections and to the choice of materials with a predominance of wooden components, up to a 3-storey configuration
Second prize was granted to Adamos Nicolaou, Georgia Thomas, Thomas Hayden, and John Wilkinson for their Mollis project, imagined around the multiple and changing needs of a textile factory.
They developed another version of a standardised cubic wooden structure module with multiple configuration possibilities, and adaptable and sliding façade components. Smooth transition scenarios were considered as well as the typologies and reuse capabilities of the building components.
Third prize was awarded to the Re-Cover project from Kieran Thompson, Andrew Chung, and Fraser Streatfield that embraced a one-storey 24-hour multifunctional urban unit. Medical, retail, exhibition, recuperation (a.k.a. nap pods) uses are foreseen to be possibly changing in short cycles within one days’ notice.
A technical and orthogonal central unit may serve attached or detached rounded nodes. Recycled plastic textiles are used to modulate varied sizes of spaces structured by cable nets, while exterior walls are proposed in ETFE cushion membranes.
Practice, Pilots and Feedback
As described in the previous article, the project was structured along the axes, and operational tools of Building Passports (400 material passports were developed), Reversible Building Design and overall Circular Building Assessment. The objectives and vison being a change of paradigm in the design and construction culture, with its respective policies and business models within a Circular Value Network.
To put into practice the concepts and principles, the BAMB consortium organised a series of Special Interest Groups and Working Packages, and developed six Pilot Projects of different characteristics in various locations.
Four of these constructions were the subject of a dedicated report coordinated by Teodora Capelle (Brussels Environment) detailing the outcomes and feedback from these on-the-field testing experiences.
Besides descriptions, illustrations and assessments of the circularity of each project, the report reflects on several key issues of the circular building industry. Business models, workflows, policies, standardisation, and implementation of Materials Passports are described according to each case study.
The report highlights the importance of a systematic approach, where different balances are taken into account. Buildings should be considered within their urban and territorial context, and major transformations along the value chain are required to achieve circularity.
Stewart Brand’s scheme of Sharing Layers of a building is recalled, highlighting the crucial role of life cycle coordination and independence of building components. These principles were applied in each of the pilot projects.
- BRIC / Build Reversible in Conception: This project was developed by Karbon architects. This Brussels Interdisciplinary Training Centre (EFP) educational and showcase tool/module of variable size (70 to 130 m²), has been assembled and disassembled on a yearly basis with proven efficacy from autumn 2017. Circularity and energy efficiency have been successfully brought together with proven high levels of airtightness and the use of wooden construction elements. Replicability and scalability of this building is possible thanks to the functional adaptability and removable foundations, compatible for shelters or temporary occupations. Some of the lessons learnt from this project include the need for an organised upfront supply system of reclaimed materials and the importance of good storage conditions and handling of materials intended to be reused. Building element connectors need to be readily removable with simple tools to avoid damaging the parts concerned.
- GTB Lab / Green Transformable Building Lab: This experimental module was developed in Ridderkerk, The Netherlands, around a multifunctional and reversible steel frame filled with interchangeable, independent, reversible wooden floor/facade/roof elements, making use of universal-standardised connections. Shape, function and size transformation is thus allowed. Construction industry partners actively participated, allowing innovative business and operation models to be investigated. This pilot project was conceived and assessed following the Reversible Building Design tools and criteria. The remarkable ease of assembly and disassembly, and of transportability favours the potential of replicability.
- REMs / Reversible Experience Modules: This was concerned with indoor interactive and modular exhibition space dedicated to circular building materials and materials passports. This travelling exhibition was installed at several locations, according to the BAMB project participation and organisation of events. 70 products that are already available in the market were showcased and labelled with a virtual Material Passport. The assembly/disassembly process was carried out six times and proved to generate almost no waste. This exhibition space system can serve multiple uses and is mainly composed of aluminium profiles for walls and ceiling, birch panels and a raised floor system of recycled calcium sulphate panels.
- CRL / Circular Retrofit Lab: Modules of prefabricated student housing assembled in the 1970’s in the VUB university campus in Brussels was the focus of this project. Research by design and process approach were applied to test reversible design and multiple reconfiguration solutions in the context of renovation and at different levels (building / space / constructive system / the components). Multiple stakeholder involvement was tackled, and innovative solutions were developed and tested for internal walls and facades. User’s needs, potentially changing over time, were considered and solutions and business models chosen accordingly.
Bringing together the lessons emerging from these circular building experiences, some general observations can be made. Considering the conception phase, it is recommended to limit the number of scenarios of adaptability to which the design should respond.
The architectural details need to be integrated from the start, especially if reclaimed products are considered for the project, and execution plans need a high degree of precision. The upfront investment implied by detailed conception and coordination would nonetheless be recovered during the execution phase, while in terms of higher investments in the construction itself, those are only justified in the long-term scope.
Whereas modularity and standardisation are essential for circular building practice, it is considered that smaller size modules allow more flexibility but would increase complexity and the number of connections. The connections themselves are key, and the use of intermediary connector elements would often apply.
Considering the technical installations/services and the loadbearing structures, these are elements with an important impact on the reversibility of buildings, and a strategic over-dimensioning would allow for additional resilience.
In terms of the materials and elements, unprocessed and non-composite materials are more suited to circularity. Multifunctional characteristics are also appreciated. The technical quality and robustness of materials would grant higher possibilities of reuse, which is more relevant when the foreseen cycle of reuse or change are short.
Facing longer rates of change, lower reuse potential may prevail and favour lower embodied energy. Reversibility of components would be limited to a certain number of cycles before eventual deterioration.
Pilots’ Learnings and Perspectives
Data handling and data sharing are essential to Building Passports, and to ensure the maintenance of value and the circular potential of buildings and elements. New technologies, such as chronological data storage (block chain) and Building Information Modelling and Methodologies (BIM) are potential enablers of systemic shifts in this domain
Transparency and open source information helping to increase market uptake and upscaling may be contradictory with current approaches towards copyrights, patents or industrial secrecy concerns.
Business models and ownership models of building components are meant to (radically) evolve, taking into account circularity as well as responsibility and assurance schemes. Service-oriented models would replace product-oriented ones within ecosystems of stakeholders functioning as collaborative (value) networks.
This is not the construction business-as-usual comfort zone, and new roles of overarching coordination emerge.
While the architect-prescriber and the client hold crucial roles, the development of circular construction relies significantly on building system manufacturing and industrial design innovation.
Procurement modalities and conditions need to integrate and reflect these goals and challenges. This applies also to policy and regulation. Circular sound ‘policy design’ needs to actively involve stakeholders. Building codes and permit procedures need to evolve into taking into consideration and allowing for the circular evolution of materials and buildings.
BAMB explored and advanced significantly in this field of research and sets a milestone merging complementary approaches. The project contributes to and sheds light onto the change that is already taking place.
The multiple branches of research and practical implementation remains open, and with sizable challenges ahead to achieve an effective change of trends, towards an effective decoupling of human wellbeing and economic activity from resource depletion and negative environmental impacts.