Building costs play a significant role in determining the affordability of a housing project, and these depend to a large extent on design choices. This paper is based on the premise that collaborative design processes, or co-design, used in collaborative housing (CH) in Europe reduce building costs and consequently increase the affordability of these housing projects. However, research remains scarce on the extent to which CH is an affordable solution from a design perspective compared to affordable mainstream housing (MH), in which no co-design is used. Therefore, this paper aims to fill this knowledge gap by assessing the impact of design choices on building costs in CH and MH. To this end, we developed a simulation model to compare the building costs of CH with MH based on their design choices. Findings indicate that CH represents a more affordable and space-efficient solution when compared to MH, if we look at the building costs per unit. This is because CH provides less expensive units while it includes larger common spaces and extra quality. These results help to refute existing claims about the unaffordability of CH design solutions.@en

Collective living is on the rise in the Netherlands. Amid an unprecedented housing crisis, more and more people are turning to collective self-organization to provide community-oriented, sustainable and affordable housing. But why are these initiatives struggling to get off the ground? And what can we learn from other European countries? "Together: Space for Collective Living" is a collection of essays, data and case studies in the Netherlands and other European countries, building on the 2021 Project Together! Knowledge. The book addresses the following questions: what is the relevance of collective living, how can we realize these forms of housing, and who can use what actions to ensure that collective living can contribute to more sustainable cities and regions? The book illustrates the dilemmas and opportunities for a new paradigm about living together in the 21st century. @en

Against the increasing commodification of housing, a new kind of housing cooperatives has emerged in Catalonia in the last decade. These cooperatives fall within the wider concept of collaborative housing (CH), i.e. they are collectively self-organised projects based on a collaborative design process, or ‘co-design’. In such a process, residents need to adjust their individual expectations and demands in order to reach a collective set of values to realise their housing project. The aim of this paper is to assess how values are set through co-design and translated into a housing project. To do so, we develop an analytical framework to conduct a longitudinal single case-study that traces back the co-design process of the resident-led housing cooperative La Borda, in Barcelona. Our findings shed light on how co-design unfolds and uncover trade-offs carried out to overcome tensions mostly between individual and collective demands and between building costs and quality.

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This thesis brings forward the design dimension, and, more specifically, co-design, to the study of housing affordability. Co-design occurs when end-users and professionals work together towards a common goal. It is a process often applied in collaborative housing, an umbrella concept encompassing different housing forms based on collective self-organisation and collaboration, where residents choose to share certain spaces. The aim of this research is to assess if and how co-design processes applied in collaborative housing may reduce building costs, thereby making these housing projects not only affordable, but even more affordable than mainstream housing. It does so by combining a case study approach with a building costs simulation. Findings indicate that co-design decisions based on a collective self-redefinition of Existenzminimum (minimum dwelling) affect the housing layout and contribute to reduce building costs. By conceptualising housing design through the lenses of affordability, this thesis highlights the understated role of architectural design and building costs as key components in the study and provision of affordable housing solutions; and enriches the existing body of knowledge on affordable collaborative housing. Moreover, it draws attention to the way some outdated building regulations and standards hamper design innovation in housing. This research ends up with a set of general principles for the co-design of affordable collaborative housing. These design principles may assist professionals supporting co-design and, more importantly, people who want to design, build and live in a collaborative manner. @en

Against the background of the current housing affordability crisis, a new wave of ‘collaborative housing’ (CH) is developing in many European cities. In this paper, CH refers to housing projects where residents choose to share certain spaces and are involved in the design phase. While many authors point to the alleged economic benefits of living in CH, the (collaborative) design dimension is rarely mentioned in relation to affordability. This paper seeks to fill this knowledge gap by identifying design criteria used in CH to reduce building costs, increasing this way its affordability. We carry out a comparative case study research, where we assess the design phase of 16 CH projects in different European cities. Findings suggest that collaborative design processes increase the chances of improving housing affordability, mainly due to the often-applied needs-based approach and the redefinition of minimum housing standards. Supplemental data for this article is available online at https://doi.org/10.1080/02673037.2021.2009778.

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In the face of societal challenges such as decreasing housing affordability, population ageing, individualisation and climate change, Europe has seen a rise in collaborative housing. Such housing comprises a wide range of collectively self-organised residential projects, which have in common collaboration between groups of residents and professionals aiming at providing affordable and sustainable housing. Despite increasing research on these practices, existing data about collaborative housing are currently scattered across national and regional levels, preventing a comparative understanding of the challenges and opportunities that these new housing forms offer. Furthermore, comparative data are needed to facilitate mutual learning and communication amongst users across countries and regions. This leads to the following research question: how can we categorise different collaborative housing forms that exist across Europe, in a way that helps compare and analyse the most salient characteristics, and so bring current scientific and applied debates further? To help fill this knowledge gap, we develop a scientifically validated categorisation of collaborative housing. To do so, we applied a mixed-methods approach including the development of a Delphi study drawing on insights from academic and practitioner experts across Europe. We provide an overview of different collaborative housing forms in Europe on the basis of data collected from Belgium, Denmark, England and Wales, France, Germany, The Netherlands, Spain, Sweden and Switzerland. The resulting evidence-based and theoretically-informed categorisation aims to contribute to the debates about the role that collaborative housing can play in solving the above challenges. We find local differences combined with international similarities, and observe tensions between generalised meanings and regional understandings.@en

During the housing crisis of the 1920s, the German concept Existenzminimum (minimum dwelling) was developed and applied to the construction of public social housing. It was considered a design laboratory, where research, design, and experimentation would focus on a unique goal: create a space-efficient affordable housing typology, based on minimum quality standards. Empirical evidence indicates a renewed interest in alternative design solutions and minimum dwelling approaches over the last decade: examples include micro-housing solutions and collaborative housing models. This is due to the current affordable crisis and the increasing trend of urbanisation. However, little is known about the current interpretation of Existenzminimum. What does the concept entail today and how has it developed? This article investigates if and how Existenzminimum is currently applied: first, it unfolds the core design principles of the original Existenzminimum. Then, these principles are used to assess if and how existing affordable or low-cost housing approaches are current (re)interpretations of the concept. Finally, the article proposes a definition for a contemporary Existenzminimum, arguing that a better understanding and awareness of the concept can help urban planners, designers, policy-makers and citizens in developing alternative affordable housing solutions.@en