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Solar Decathlon Europe 2022

Created on 13-11-2023 | Updated on 13-11-2023

Solar Decathlon Europe (SDE) is a university competition where student-led teams undertake the challenge of designing and constructing highly innovative and environmentally sustainable 1:1 scale House Demonstration Units (HDU). Originally launched in the USA in 2002, the competition expanded its reach to Europe in 2010 (SDE, 2019). Competing teams typically involve research groups within universities and are sponsored by industry partners, such as contractors and product manufacturers. After the competition, the homes become accessible to the public, featuring guided tours that highlight the cutting-edge advancements in sustainable housing.

Although the competition’s primary design challenge focuses on minimising operational carbon, participating teams must also address the path towards achieving a climate-neutral building stock. The construction task requires teams to create prefabricated building systems, assemble their HDU at a site in their home country, disassemble it, then transport and reassemble it within just two weeks at the competition site, known as the Solar Campus. This means design for disassembly and circularity are integral to the competition, making it a unique opportunity to demonstrate how permanent housing (as opposed to temporary or emergency housing) can be designed to reduce embodied carbon throughout the whole life cycle and discourage potential future demolition.

The SDE-2022 edition took place in Wuppertal, Germany under the theme “SDE Goes Urban!” Sixteen teams from countries including Czechia, France, Germany, Hungary, Netherlands, Romania, Spain, Sweden, Taiwan and Turkey took part in the build challenge. Teams were awarded points in ten categories, covering environmental and social sustainability aspects, as well as affordability and viability. This case study provides an overview of the SDE competition in 2022, which was attended by the author on-site. More information about the visit can be found in this blog post.

16 competing universities

Wuppertal, Germany

Project (year)

Construction (year)

Housing type
multifamily housing

Urban context
City centre

Construction system
Prefabricated sustainable homes designed and built to be disassembled and relocated for reassembly



Relationship to urban environment

The SDE 2022 competition called for innovative urban housing solutions within existing contexts, allowing teams to choose from one of three scenarios: (1) a vertical extension adding additional storeys, (2) closing gaps between buildings, or (3) a horizontal extension. Among the sixteen built projects, eleven were top-ups, four were in-fill, and one was a horizontal extension. Some teams opted for a top-up solution for the existing Café Ada site in Wuppertal, whilst others produced solutions tailored to a local context of their home country. Despite the diverse origins of the projects, all of them had to be transported and operated at the Solar Campus in Wuppertal, Germany. Table 1 shows the results of the competition, which was won by team RoofKIT from the Karlsruhe Institute of Technology. Note that the third place was tied between teams SUM from TU Delft and Aura from Grenoble School or Architecture.

Innovative aspects of the housing design/building

As documented in the competition Source Book (Voss & Simon, 2022), the teams developed various innovative biological, low-carbon, and circular materials and products from various other sectors, such as mycelium bound insulation, sea grass, recycled newspapers, jeans for insulation, and recycled yoghurt pots for kitchen and bathroom joinery. Chalmers University’s Team Sweden experimented with 3D printed cellulose whilst team X4S from Biberach University of Applied Sciences used tubular thin film photovoltaics, originally developed for large-scale use in agriculture, as pergola roofing. Innovative layouts included tessellating modules to provide multiple configurations, and highly efficient living units for multiple households (SDE, 2022).

Construction characteristics, materials and processes

All teams used Industrialised Construction (also known as Modern Methods of Construction in the UK) to varying degrees to prefabricate their buildings in their home countries. Construction included timber-based 3D modular and 2D panelised elements, and the competition also required the use of BIM to model the designs. To be able to disassemble and reassemble the HDUs they had to avoid the use of glues and wet sealants and instead join the building parts using various forms of reversible connections. Strategies included interlocking wood jointing, steel plates and footings, tapes, and mechanical joints such as screws, rivets, and bolts (Voss & Simon, 2022). These joining methods were designed to withstand water-ingress as well as airtightness, which was tested using the blower door test.

Energy performance characteristics

High energy efficiency performance and the production of on-site renewable energy were critical design aspects of the competition. All homes were designed to use electricity as the sole energy source for energy services and were powered by air- and ground-source heat pumps, and photovoltaic panels were integrated both horizontally on roofs and vertically on façades, depending on whether the project responded as an infill or top-up solution (Voss & Simon, 2022). Nine HDUs met the Passive House standard and included innovative passive strategies, such as solar chimneys, which were implemented by five teams, including Azalea from the Polytechnic University of València. Eight of the sixteen teams were chosen to remain on-site for an additional 3-5 years after the competition as Living Labs to provide in-use research data (University of Wuppertal, 2022).

Involvement of other stakeholders

The competition incorporates a level of entrepreneurship, with teams encouraged to forge partnerships and gain sponsorship from various industry partners. This provided teams with a mixture of financial support, in-kind services, or donations of materials and products. The extent of collaboration with partners and sponsors varied across the teams: these were formed not only with contractors and product suppliers, but in some cases with housing associations and local municipalities as well. The involvement of stakeholders from different fields not only fostered collaboration between fields, but brought about innovative construction solutions, bridging the gap between academia and industry.

Alignment with project research areas

Solar Decathlon Europe is an architectural competition for sustainable housing which focuses on the quality of design and construction. Financing is integral to the realisation of the projects and is managed by the student teams. Community participation is not a requirement of the competition and the HDU’s on the Solar Campus do not provide housing for the public.

Design, planning and building (Highly related)

The competition is based on the design and build challenges that focus on the architecture and engineering dimensions with consideration for urban design and potentially responding to different contexts. Detailed design criteria are assessed within the Architecture and Engineering & Construction contests and include aspects such as aesthetic design quality, structure, durability, coherence of the design, and energy performance (SDE, 2021)

Policy and Financing (Moderately related)

SDE 2022 provided financial support of €100,000 as base funding. Teams were then responsible for raising additional funds though sponsorship and donations. Regarding the concept design, affordability was taken seriously by the teams, whose proposals also included considered business cases for affordable and social housing solutions.

Community participation (Not related)

Solar Decathlon was not designed to be a participatory project. However, due to the high media coverage, the competition tends to generate a considerable amount of public interest. An additional objective of the competition is to generate social awareness and educate the general public to understand the SDE topics and the need for an energy transition in the built environment.

Design, planning and building

Community participation

Policy and financing

* This diagram is for illustrative purposes only based on the author’s interpretation of the above case study

Alignment with SDGs

The competition is “completely in the spirit of sustainable development” as the competition centres on developing housing solutions reflecting the needs of future generations (Voss & Simon, 2022). Most teams directly aligned their proposals to the UN Sustainable Development Goals within their submitted project manuals. The Solar Decathlon Europe competition demonstrates particular alignment with the following targets:

7a “By 2030, enhance international cooperation to facilitate access to clean energy research and technology, including renewable energy, energy efficiency and advanced and cleaner fossil-fuel technology, and promote investment in energy infrastructure and clean energy technology” | The competition was founded on developing highly energy efficient housing based on renewable energy.

11.1 “By 2030, ensure access for all to adequate, safe and affordable housing and basic services and upgrade slums” | With “housing becoming scarcer and more unaffordable for large numbers of people” (Voss & Simon, 2022) the teams proposals addressed a lack of adequate and affordable housing in urban contexts.

11.6 “By 2030, reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management” The teams provided circular housing solutions that minimises waste in both the short and long term.

13.3 Improve education, awareness-raising and human and institutional capacity on climate change mitigation, adaptation, impact reduction and early warning” The competition improves knowledge around climate change mitigation in the built environment for a new generation of young design professionals and participating industry partners through the design and build challenges. The innovative solutions are showcased with open events to raise awareness internationally with the general public.


SDE. (2019). The SDE story.

SDE. (2021). Solar Decathlon Europe goes urban Wuppertal Germany - rules version 2.1.

SDE. (2022). SDE 21/22 Teams are the future.

University of Wuppertal. (2022). Herzlich Wilkommen beim Living Lab NRW.

Voss, K., & Simon, K. (2022). Solar Decathlon Europe 21/22 - Competition Source Book (1st ed.). University of Wuppertal.



SDE-2022 competition results:

Archive of previous Solar Decathlon projects:


Related vocabulary


Design for Dissassembly

Industrialised Construction

Area: Design, planning and building

Building Information Modelling (BIM) is the process of creating a set of digital representations which consists of both graphical and non-graphical data for the entire building cycle  (Eastman et al., 2011). This process involves documenting, gathering, organising, and updating this information throughout the whole life cycle of a building from conception to demolition (Eschenbruch & Bodden, 2018). Beyond the demolition stage BIM can also support circular principles; managing the re-use, recovery, and recycling-potential of a building (Akbarieh et al., 2020; Xue et al., 2021). Whilst the concept of BIM as a process is supported by the International Organisation for Standardisation in ISO 19650-1:2018 (ISO, 2018), the National BIM Standard describes BIM as a digital technology (NBIMS-US, 2015). Despite the origins of BIM dating back to the 1970s, it did not become widely adopted by the Architecture, Engineering and Construction (AEC) industry as a computer design tool until the 2000s (Costa, 2017). The digital building information model uses intelligent objects to store information in the form of three-dimensional geometric components along with its functional characteristics such as type, materials, technical properties, or costs (Eschenbruch & Bodden, 2018). This model forms the basis of a shared knowledge resource to support the various digital workflows of multidisciplinary stakeholders (Chong, Lee and Wang, 2017; Barile et al., 2018). Moreover, it serves the purpose of visualisation, clash detection between different building components, code criteria checking, environmental analysis, and cost estimation to name a few (Kamel & Memari, 2019; Krygiel & Nies, 2008). Therefore, utilising BIM can improve construction accuracy and enhance the built asset’s performance (Kubba, 2017; Love et al., 2013). The building information model facilitates the knowledge transfer between experts and project participants to satisfy end-user needs and support early-stage decision-making (Chong et al., 2017; Lu et al., 2017). Therefore, BIM can be considered a transdisciplinary practice as it communicates AEC, computation, and science (Correia et al., 2017). In the AEC industry implementing BIM involves several stages, which are known as BIM maturity models. The maturity here means the extent of the user’s ability to produce and exchange information. These stages are the milestones, or levels, of collaboration and sharing of information that teams, and organisations aspire to. Defining these milestones is the main purpose of the different BIM maturity models that exist nowadays (Succar et al., 2012). The European Commission (EC) encourages step-by-step maturity models starting from BIM level 0 up to 4, to move the industry from a traditional modelling approach towards an open BIM approach. According to the EC, to reach BIM level 4 “all project, operational documentation and history are linked to objects in the model” (European Commission, 2017). Due to growing concerns over the environmental, economic, and social impacts of the built environment, BIM is increasingly used to facilitate various sustainability analyses. In this regard, the concept of Green BIM initiated as the systematic digitalisation of building life cycles to accomplish established sustainability goals (Barile et al., 2018; Wong & Zhou, 2015). As such BIM has been integrated with Life Cycle Analysis (LCA), Life Cycle Costing Analysis (LCCA), and recently with Social Life Cycle Analysis (S-LCA) (Llatas et al., 2020). Today several BIM applications perform sustainability analysis in conjunction with Green Building Rating Systems (Sartori et al., 2021). In relation to housing BIM plays a crucial role in addressing affordability and sustainability issues from creation to maintenance, as well as the beyond end-of-life phases. However, many challenges remain for it to be fully and inclusively integrated within the AEC practice and for the full potential of BIM to be realised.

Created on 16-02-2022

Author: A.Elghandour (ESR4), A.Davis (ESR1)


Area: Design, planning and building

Design for Disassembly (DfD), also referred to as Design for Deconstruction or Construction in Reverse, is the design and planning of the future disassembly of a building, in addition to its assembly (Cruz Rios & Grau, 2019). Disassembly enables the non-destructive recovery of building materials to re-introduce resources back into the supply chain, either for the same function or as a new product. Designing buildings for their future disassembly can reduce both the consumption of new raw materials and the negative environmental impacts associated with the production of new building products, such as embodied carbon. DfD is considered the “ultimate cradle-to-cradle cycle strategy” (Smith, 2010, p.222) that has the potential to maximise the economic value of materials whilst minimising harmful environmental impacts. It is therefore a crucial technical design consideration that supports the transition to a Circular Economy. Additional benefits include increased flexibility and adaptability, optimised maintenance, and retention of heritage (Rios et al., 2015). DfD is based on design principles such as: standardised and interchangeable components and connections, use of non-composite products, dry construction methods, use of prefabrication, mechanical connections as opposed to glues and wet sealants, designing with safety and accessibility in mind, and documentation of materials and methods for disassembly (Crowther, 2005; Guy & Ciarimboli, 2008; Tingley & Davison, 2011). DfD shares commonality with Industrialised Construction, which often centres around off-site prefabrication. Industrialising the production of housing can therefore be more environmentally sustainable and financially attractive if building parts are produced at scale and pre-designed to be taken apart without destroying connecting parts. Disassembly plays an important role in the recovery of building materials based on the 3Rs principle (reduce, reuse, recycle) during the maintenance, renovation, relocation and reassembly, and the end-of-life phases of a building. Whilst a building is in use, different elements are expected to be replaced at the end of their service life, which varies depending on its function. For example, the internal layout of a building changes at a different rate to the building services, and the disassembly of these parts would therefore take place at different points in time. Brand’s (1994) Shearing Layers concept incorporates this time aspect by breaking down a building into six layers, separating the “site”, “structure”, “skin” (building envelope), “services”, “space plan”, and “stuff” (furniture) to account for their varying lifespans. DfD enables the removal, replacement, and reuse of materials throughout the service life of a building, extending it use phase for as long as possible. However, there is less guarantee that a building will be disassembled at the end of its service life, rather than destructively demolished and sent to landfill.

Created on 18-10-2023

Author: A.Davis (ESR1)


Area: Design, planning and building

Industrialised Construction, also referred to as Modern Methods of Construction in the UK (Ministry of Housing, 2019) and Conceptueel Bouwen (Conceptual Building) in the Netherlands (NCB, n.d.), is a broad and dynamic term encompassing innovative techniques and processes that are transforming the construction industry (Lessing, 2006; Smith & Quale, 2017). It is a product-based approach that reinforces continuous improvement, rather than a project-based one, and emphasises the use of standardised components and systems to improve build quality and achieve sustainability goals (Kieran & Timberlake, 2004).  Industrialised Construction can be based on using a kit-of parts and is often likened to a LEGO set, as well as the automotive industry's assembly line and lean production. Industrialisation in the construction sector presents a paradigm shift, driven by advancements in technology (Bock & Linner, 2015). It involves both off-site and on-site processes, with a significant portion occurring in factory-controlled conditions (Andersson & Lessing, 2017). Off-site construction entails the prefabrication of building components manufactured using a combination of two-dimensional (2D), three-dimensional (3D), and hybrid methods, where traditional construction techniques meet cutting-edge technologies such as robotic automation. Industrialised construction is not limited to off-site production, it also encompasses on-site production, including the emerging use of 3D printing or the deployment of temporary or mobile factories. Industrialised Construction increasingly leverages digital and industry 4.0 technologies, such as Building Information Modelling (BIM), Internet of Things, big data, and predictive analysis (Qi et al., 2021). These processes and digital tools enable accurate planning, simulation, and optimisation of construction processes, resulting in enhanced productivity, quality, and resource management. It is important to stress that Industrialised Construction is not only about the physical construction methods, but also the intangible processes involved in the design and delivery of buildings. Industrialised construction offers several benefits across economic, social, and environmental dimensions. From an economic perspective, it reduces construction time and costs in comparison to traditional methods, while providing safer working conditions and eliminates delays due to adverse weather. By employing standardisation and efficient manufacturing processes, it enables affordable and social housing projects to be delivered in a shorter timeframe through economies of scale (Frandsen, 2017). On the social front, Industrialised Construction can enable mass customisation and customer-centric approaches, to provide more flexible solutions while maintaining economic feasibility (Piller, 2004). From an environmental standpoint, industrialised construction minimises waste generation during production by optimising material usage and facilitates the incorporation of Design for Disassembly (Crowther, 2005) and the potential reusability of building elements, promoting both flexibility and a Circular Economy (EC, 2020). This capability aligns with the principles of cradle-to-cradle design, wherein materials and components are continuously repurposed to reduce resource depletion and waste accumulation. Challenges remain in terms of overcoming misconceptions and gaining social acceptance, the slow digital transformation of the construction industry, high factory set-up costs, the lack of interdisciplinary integration of stakeholders from the initial stages, and adapting to unconventional workflows. However, Industrialised Construction will undoubtedly shape the future of the built environment, providing solutions for the increasing demand for sustainable and affordable housing (Bertram et al., 2019).

Created on 09-11-2023

Author: C.Martín (ESR14), A.Davis (ESR1)


Related publications

Davis, A. (2022, August). Designing housing to meet circular goals: industrialised construction in combination with design for disassembly. In New Housing Researchers Colloquium (NHRC) at the European Network for Housing Research (ENHR) Conference 2022, Barcelona, Spain.

Posted on 31-08-2022




Icon solar-decathlon-competition-and-lca-secondment-with-upv

Solar Decathlon Competition and LCA | Secondment with UPV

Posted on 27-10-2022

Leading up to the summer I completed my first secondment of three months at the Universitat Politènica de València (UPV), which was conveniently only a three-hour journey south along the Spanish coast from my host institution in Barcelona.   Life in Valencia involved drinking copious amounts of horchata (a local drink made from tiger nuts called Xufa) and enjoying Jardin del Turia, a park that was once a river which today hosts attractions such as gardens, sports facilities, and futuristic cultural buildings designed by architect Santiago Calatrava. I had the pleasure of working with my co-supervisor Ignacio Guillén and Life Cycle Assessment (LCA) expert Alberto Quintana Gallardo, Ph. D. in the department of Applied Physics. Together they provided excellent support with my plans to investigate housing projects from this year’s Solar Decathlon competition and to learn and apply LCA to built case studies during my stay.   As my project investigates Design for Disassembly (DfD) – in addition to Industrialised Construction – the Solar Decathlon competition was an exciting and unique opportunity to observe the disassembly and reassembly of sustainable homes, including the Spanish entry from team Azalea at UPV. As a former practicing architect where I worked with sustainability consultants who normally carry out LCA’s, I was also very eager to learn how to actually do an LCA myself.   Solar Decathlon So what is the Solar Decathlon competition? It is an international competition where teams from universities build prototype homes known as ‘House Demonstration Units’ (HDU) that showcase the best in innovation and energy efficiency using renewable energy. Although the design aspect of the competition focusses on minimising operational carbon, the build challenge requires teams to first construct their HDU at a site in their home country, disassemble it, then transport and reassemble it in only two weeks at the competition site, also known as the Solar Campus. This means designing for disassembly is integral to the competition, making it a fantastic opportunity to study how housing can be more resource efficient over the building life cycle and understand practical building issues.   The competition and reassembly of the houses took place this year in May at the Solar Campus in Wuppertal, Germany. The 16 teams that made it to the build phase heralded from the Netherlands, France, Sweden, Romania, Czech Republic, Turkey, Taiwan, Germany itself, and of course Spain.   I seized the opportunity to observe and ask questions about the disassembly process, the reassembly process, and carry out interviews with each of the Solar Decathlon teams. When I arrived at UPV at the start of May, Team Azalea from UPV had finished building their HDU called the Escalà project on campus and had just held their inauguration event. Over the first two weeks of my secondment, I visited the house every day whilst it was slowly disappearing as it was taken apart and loaded onto five trucks headed to Germany, where the team would shortly reassemble it all over again! During this time, I got to know the team members who had bonded immensely during the intense competition period until this point. Before heading to Wuppertal myself, I was able to pilot interview questions covering technical and environmental sustainably aspects of the project with the Azalea team, as well as remotely with the SUM team from TU Delft.   The energy at the Solar Campus in Wuppertal was palpable as the teams were busy reassembling their HDU’s, each had an internal floor area of around 70m2 to give an idea of scale. I quickly got to know each of the projects and schedule interviews with the 16 teams, who kindly volunteered their time during the middle of the hectic reassembly period before the houses were judged and opened to the public. I managed to interview 13 teams on-site (the remaining teams were later interviewed online), including participants from different fields and both students and professors. Each team had a unique solution to the brief which called for either vertical and horizontal extensions or in-fill proposals. It was not only insightful but a pleasure speaking with true pioneering experts in housing designed for disassembly. Now’s time to complete the analysis of all that data!   Check out my Instagram highlights of SDE-22 for some on-the-ground footage.   LCA Life Cycle Assessment (LCA) is an increasingly popular methodology and decision-supporting tool used by industry professionals and scholars to measure and compare the environmental impacts of buildings (European Commission, 2010). An LCA can be used to calculate Whole Life Carbon (WLC), which includes both embodied carbon from all the materials, processes, and transport to construct buildings and the operational carbon produced whilst a building is inhabited. WLC assessments are crucial to set environmental targets to decarbonise our building stock. There is currently a big knowledge gap around LCA amongst architectural practitioners and other stakeholders involved in the delivery of housing, partly due to the time-consuming nature of LCA’s. An LCA can be calculated simply with an excel spreadsheet or using various online platforms and plug-ins such as OneClick LCA, but amongst scholars more heavy software is called for, such as SimaPro – which is was what I would be learning to use whilst at UPV. My aim here was to carry out cradle-to-cradle LCA’s of case studies to quantify the benefits of DfD and the consideration of different lifespans for different parts of the building.   Work began on the first case study of a house designed and delivered by my co-supervisor Ignacio Guillén called Edificación Eco-Eficiente, or ‘EEE’, this was awarded a Class A energy rating and was the first single-family home in Spain to achieve the maximum VERDE* rating of 5 leaves. EEE was built using Industrialised Construction and prefabricated 2D elements that were assembled on-site in only 19 days. I was also able to visit the house on the UPV campus, though due to security reasons it can’t be used as a living-lab, which is a shame as it could provide some great in-use data on energy efficiency!   Using Simapro was (and still is) a steep learning curve with an incredible amount of precise and technical information that needs to be included. Imagine having to enter every single built element manually into a software, and not just modelled 3D objects but also coatings such as the surface area of zinc needed to galvanise steel, the grouting between tiles… the list goes on. Needless to say, LCA is an invaluable tool and will contribute greatly to my doctoral research project.     ¡Hasta pronto! I will be seeing my colleagues in Valencia again next month for the VIBRArch conference held by UPV to present my ongoing work on LCA. My secondment was invaluable in learning new skills and creating connections, particularly through the Solar Decathlon competition that I am continuing to follow up. Thank you to everyone at UPV, the Azalea team, and Solar Decathlon participants who provided such positive experiences and research opportunities!      *VERDE is a sustainability certification developed by Green Building Council Spain     Bibliography   Solar Decathlon Europe Competition website and knowledge platform with previous year’s entries   Team Azalea’s Instagram page and website   London Energy Transformation Initative ‘LETI’ provide an excellent embodied carbon primer for further reading on Whole Life Carbon     References European Commission. (2010). ILCD Handbook - General Guide for Life Cycle Assessment: Detailed Guidance (1st ed.). Publications Office of the European Union.  

Author: A.Davis (ESR1)



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