Why and how cities can promote affordable and sustainable Collaborative Housing

Presentation, notes, Q&A and Toolbox from the conference organised at ISHF 2023 by urbaMonde and NETCO

Why should and how can local governments support the emergence of affordable Collaborative Housing forms on their territory? What is the role of social housing and the public interest in this new wave of projects emerging across Europe?

Our partner urbaMonde and NETCO organised a session at the International Social Housing Festival in Barcelona, on the 7th of June 2023. You can find the presentation here, and the transcription below.

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Session organised and chaired by


Robert Temel, Pierre-Charles Marais, Javier Burón, Pierre Arnold, Jeroen Laven, Charlotte Grosdidier, Rebecca Bosch, Maite Arrondo.

Main takeaways for policy-making

WHY: Benefits of Collaborative Housing for cities:

  • Collaborative Housing is generally a community-led, bottom-up initiative that thrives where the group can purchase land to build, or existing buildings to renovate. This makes it hard to occur in cities without public support to ensure these projects are both affordable and non-speculative.
  • Experience shows that Collaborative Housing projects manage very high environmental quality and energy-efficiency (often higher than the current standards), as people build for themselves and through collective intelligence, the best choices are made.
  • Similarly, CH groups spontaneously try to generate a diversity of households (ages, origins, household compositions…) and often include homes for specific vulnerable populations (asylum seekers, migrants, people with disabilities, single mothers, students…). However, the diversity of income-groups depends on the public funding available to cover the gap for low-income households to participate.
  • CH projects are generally mixed use, with facilities and activities open to the neighbourhood, people committed to sustainable ways of living (shared mobility, local food, renewable energies, etc.) and solidarity with vulnerable groups or processes affecting the neighbourhood (gentrification, COVID).

HOW: Public support to Collaborative Housing

  • In Barcelona, Brussels, Lyon and Vienna, Collaborative Housing is supported by the local or regional government when the households respect the criteria of social housing (under an income threshold, not owning another home). However generally it corresponds to the upper income-categories of the social housing ceiling (middle and lower-middle incomes).
  • Collaborative Housing non-profit developers can be recognised as social housing providers, which allows them to access direct subsidies and municipal tax reductions like the housing cooperatives in Barcelona and the Community Land Trust (CLT) in Brussels.
  • Alternatively, collaborative housing groups can partner with institutional rental social housing developers to set-up mixed projects (social rental + cooperative ownership or cohousing on the same plot), using the know-how and legal guarantees of the institutional developer.
  • Public land can either be sold at reduced price for non-profit collaborative housing like in Lyon and Vienna or leased over 99-years with a symbolic rent like in Barcelona and Lyon.
  • The formal recognition by the authorities and public guarantees of bank loans give security to the private financial actors to issue loans to CH groups for the building or renovation process.
  • Regional, national, or European public development banks can contribute to funding for City-scale development projects involving CH, like in Barcelona.
  • Public tenders which generate competition between CH groups and with other affordable housing developers work in Vienna but not in Barcelona, where the municipality has decided to establish an agreement with all affordable housing providers who agree on one single project for each public plot.
  • Participation in a CH process requires cultural assets, and time, which tends to be a barrier between low- and middle- income groups. External technical and social assistance is needed to facilitate the CH group constitution and the design process with architects, social developers, public authorities, etc. The “Fabrique de l’Habitat Participatif” subsidised by the Grand Lyon authority gathers the professionals who work with interested groups as a single-entry point to dialogue with the public actors.
  • The “Fabrique de l’Habitat Participatif” also works with local community groups and associations to foster CH projects in neighbourhoods that are not yet attractive for the housing market.
  • Mutual trust between CLH groups and public authorities is the key ingredient for success.

Notes: WHY and HOW to promote Collaborative Housing

Vienna, Austria

Robert Temel:Working with CH in Vienna for 15 years now. CH projects have existed in Austria since the 1970’s, and a more recent wave started because of the 2007-2008 crisis, around 2010. CH implement elements that are often missing in the housing market and in social housing like: self-organisation, community, improved sustainability, mixed-use projects, innovative typologies.

Two important public tools that CH projects can benefit:

  • Housing Subsidies: these are not specific to CH but most CH projects are therefore under the conditions of subsidised homes and collective ownership (not individually owned apartments).
    ✔️ Enables low rents which include low- and middle-income households.

  • Concept tendering procedures: sales procedure to buy land from the Viennese land fund for subsidised housing which has a small share of its land for CH projects. CH groups compete with each other for land but not with professional housing developers. Price of the land is fixed and the decision on the buyers is based on project quality criteria.
    ✔️ Enables to implement the projects in the City where land prices are high.
    ✔️ From the policy point of view, it facilitates social mixing in development areas.

One standard partnership practice:

  • In the city, CH projects don’t build alone, they collaborate with Limited-profit developers (LPDs) from whom they buy or rent the homes after completion.
    ✔️ Non-speculative land tenure keeps the rents affordable forever (no time limit).
    ✔️ The partnership ensures a professional development of the real estate project.

Example of Gleis21 in Vienna: wood building completed in 2019, 35 apartments of subsidised housing, ground floor open to the neighbourhood (event hall, cultural activities, artists’ studios, music school), communal facilities on the roof. Co-residents involved in neighbourhood reflection groups on mobility.

CO-HOPE research project: A “Living Lab” (series of workshops) is currently being implemented in Vienna with co-residents of different CH projects and people who are not yet living in a CH to learn from their experiences. Together with urbaMonde and academic partners, policy recommendation will be derived from the projects’ learnings to promote more affordable CH in Austria, France, Spain, Sweden.

Habitat Participatif France

Pierre-Charles Marais:HPF is a network created over 10 years ago to federate cohousing groups as well as professionals in the field, associations, to spread CH and give a voice to the organised residents as legitimate actors in the built-environment sector.

There is often a critique against CH that there is a lack of social diversity. This is unfortunately due to lack of public policies that allows to reduce costs and development time of the CH projects to include vulnerable groups. As CH is recognized for its social value and common interest, policy support is needed to open it up for other social groups.

Social housing is a very technical field which is difficult to understand and participate in when you are a citizen without background or training in the field. The fact that in countries like Switzerland where the housing policy is decentralised facilitates the experimentation and implementation of CH practices. In France, there are 400 CH inhabited and almost 1,000 if you include those that are in preparation. Of these only projects 33 (435 homes), less than 8%, include social rental housing for low-income people. At least they demonstrate that it is possible to combine CH with the work of social rental housing developers.

A 2022 study about these cases is available online:

  • Very diverse projects: rural/urban, small/big, new buildings/rehabilitation, as well as a mixture of rented social housing and privately or cooperatively owned housing.
  • Collaborate with future co-residents in the design of the homes and common areas. This helps to give identity, creativity and humanity to the project, adapted to different situations. On one hand, not every desire is technically or legally possible to include in the projects, on the other, residents may have other priorities or ways of using the spaces that the architects and the social developer anticipate, which makes this process interesting and beneficial for all. Trust and commitment are generated in the process.
  • Sustainable long-term management of the buildings: formalising co-management contracts (i.e. residents commit to take care of the green areas instead of outsourcing it, which reduces costs), providing conflict management tools and procedures are essential.
  • Shared/mutualised spaces: these are key for the development of social life, mutual help, solidarity, interaction between co-residents and with people from the neighbourhood. This enhances the sustainability: shared garden, shared cars, cultural facilities, and events, etc.
  • Most CH projects are initiated by a group of citizens, but in the case of CH + Social Housing these projects are mostly fostered by municipalities (urban planning tools, tenders on public land…). An external social and technical assistance is recommended to hire as an intermediary between all stakeholders.
  • These projects represent huge social and environmental benefits for cities.

Grand Lyon, France

Charlotte Grosdidier:Grand Lyon includes 59 municipalities, second largest metropolitan area in France. 2.5 million inhabitants. 500,000 new inhabitants in 15 years contributed to a high pressure on housing markets and social rental housing (1 to 10 ratio between offer and demand). Current objective 2022-2026 is to produce every year: 5,000 social rental housing units, 100 non speculative home ownership homes (Bail Réel Solidaire) and one non-speculative Cooperative Housing project in each development zone. CH empowers the residents in the process of producing affordable housing.

Started with an experimental pilot project in 2009-2011: Le Village Vertical: 10 apartments of coop residents « the villagers », + 9 household income social housing + 4 apartments for young people in social programs + 24 apartments for affordable housing (subsidised ownership).

  • Built by social housing provider Rhône Saône Habitat.
  • Land sold by the Grand Lyon metropolitan area at a reduced price for the social housing purpose.

Currently 90 housing units in 6 finished buildings, ~150 housing units in 7 projects to come. For new projects, Grand Lyon requested project groups and CH facilitators (technical + social assistants) to group in a single organisation to have a single point of contact: La Fabrique de l’Habitat Participatif.

  • La Fabrique informs and trains the people who are interested in CH, support groups in developing their projects (cooperative or other land tenure forms), matching them with land opportunities from the Grand Lyon.
  • Urban renewal strategies included CH projects. 2 case examples:

Example of Le Moulin (Lyon), 7 apartments in a rehabilitated building in a gentrified neighbourhood. Public Land of the Métropole du Grand Lyon with a 99 years lease to the cooperative. Household’s income must be below the social housing income threshold. Example of l’Oasis (Saint-Priest), co-housing in social housing. 40 apartments of which 20 for seniors and 20 for families. The project was co-designed with the senior resident’s association “L’Oasis des Babayagas”.

Projects under development:

Example of la Sauvegarde (Lyon) low-income neighbourhood. 15/20 apartments in homeownership with a priority given to households who currently live in social housing, and then other households interested to complete the group, if necessary. First project in collaboration with « La Fabrique » which works with local associations of the neighbourhood to create a CH group where it is hard to mobilise residents. Land is sold by a public land developer at a reduced price.

Example of Les Girondins (Lyon), urban renewal project of an area which will include 2 housing coop with 15 housing units each, and one project of 50 housing units with a real estate promoter. The public land developer of la Métropole sold at a reduced price with a household income limit for social housing.

Strengths of the collaborative housing model:

  • Community involvement in the neighbourhood
  • High housing performance (density, mixed-uses)
  • Sustainable housing


  • Location bias depending on the attractivity of the neighbourhood.
  • Costs: High land prices, recent increase in bank interest rates, High construction costs.

Brussels Region

Rebecca Bosch:Brussels Housing is an entity of the Brussels Regional Government. Still in the early stages of structuring the model. Since the creation of the Community Land Trust Brussels (CLTB) 10 years ago, Brussels Housing became more involved in supporting CH through the CLT model. CLTB’s vision was perfectly aligned to the regional administration’s objectives and received support from the region. CLTB homes are permanent affordable homes for low-income households. Land is managed as a common good, so housing remains affordable to the future generations and CLTB does community work with residents, they organise neighbourhood activities. The region has supported it since the beginning by adapting the legislation, through management contracts and funding.

The CLT model in Brussels is based on:

  • Acquisition and stewardship of the land in benefit of the residents and wider community.
  • Homeowners are individual residents or cooperatives which rent the homes out to their members.
  • Resale price of the homes is limited to preserve affordability.
  • Conditions oriented to vulnerable populations: the beneficiaries must meet the criteria of social housing (not own another dwelling, income under a threshold).
  • Over 100 dwellings constructed and 7 projects under construction for another 85 dwellings.

Public support:

  • Subsidies from the region can be received for this affordable housing form (CLTB was officially recognized in 2012 in the Housing Code).
  • April 2021, decree organising the regional land alliances, their accreditation and financing. This new legislation of the sector made it possible for new actors like the * CLTB to enter the regional land alliance and get access to land.
  • CLTB is recognised as an official operator of social housing which makes it a non-profit housing provider with favourable financial conditions to develop projects (i.e. 6% VAT for real estate transactions instead of 21%) and specific annual subsidies.
  • In 2022, CLTB received from the region 3 M€ investment subsidies and 500,000€ operating subsidies. Support has been growing annually.

Example of CALICO (Brussels): Care and Living in Community. UIA EU-funded project that finance both the City and non-profit partner, CLTB. 34 dwellings on CLTB land, low-income families, single-headed incomes, elderly women, in a caring environment. Integration of a “birth and end of life” facility in the building. Two housing first homes. Two common spaces for residents and one open to the neighbourhood.

City of The Hague

Jeroen Laven:He lives in a market version of a cooperative in Rotterdam. The Hague is the most densely populated city in the Netherlands (50% higher density than Amsterdam) with a major housing shortage.

There is an urgent need for housing for vulnerable target groups such as immigrants, refugees, former homeless people, or people leaving care institutions. There are no CH projects in The Hague yet, just going to start a CH programme this year because there is a need for this specific kind of housing in the city with the following objectives:

  • More diverse and inclusive city with innovative & collaborative housing concepts that invites people to meet and connect.
  • More social cohesion: a closer relationship between resident, neighbour and living environment.
  • More (collective) ownership and involvement of future residents.
  • Better housing solutions for specific groups and needs.
  • New urban architectural concepts.

Concrete goals and budgets:

  • 100 social homes in CH a year (each year 4,000 new homes in the city of which 30% must be social housing including CH).
  • The housing corporations which own around 35% of the homes in The Hague will also have to contribute to the creation of CH.
  • 5 M€ budget over four years to accelerate affordable housing concepts, plus additional funding for vulnerable target groups.

Method to implement affordable housing solutions including CH:

  • Identification of vacant buildings and land where mixed projects could fit, involving partnerships, and combining different policy goals.
  • Communication and connections between stakeholders (City Makers festivals in September 2023).
  • Possibility of subsidising the start-up phase of collaborative housing projects.
  • A revolving fund to cover the funding gap that housing cooperatives need to purchase land.

Challenge and doubt about potential competition between social rental housing (with long waiting lists) and CH. Why to prioritise land for CH instead of classical social rental.

City of Barcelona

Javier Burón:In recent years the Municipality of Barcelona has done “jujitsu”, benefiting from an energy that was already present in the society. When they wanted to see the different instruments intervene in the social and affordable housing sector, they noticed that there was already a movement integrated by activists, professionals, academics, and others working on solutions and demanding support from the administration. Is also a way to diversify the provision of affordable housing, fighting segregation. To do so, they had to “hack the code” to change the way administration works. In the stage of replicating and scaling up for hundreds of homes to reach the critical mass and become a mainstream way to provide housing.

Method to promote affordable CH:

  • Policy that started with the goal of fostering a sector based on “Zero Net-Equity cooperatives”: non-profit cooperatives build and manage the buildings, the ownership is collective, but the use is individual (inspired by cooperatives in Uruguay and Denmark).
  • CH users must comply with the social housing criteria (no other property owned, incomes below a threshold, and be registered as current residents of the city when they apply) as well the cooperative housing membership rules that each cooperative creates.
  • Land is almost provided for free to the cooperatives: the City Council grants a surface right over buildings or a public land leasehold over a plot for 75-99 years (renewable).
  • Refundable Grant, up to 16% of the total budget of the construction development costs. Coops return it once they have paid the mortgage.
  • Public Bank line from Catalonia (ICF, ICO) and EU (EIB) to provide affordable finance to Cooperatives and Foundation. The municipality provides a financial guarantee.
  • Municipal tax cuts
  • NextGeneration EU funding: up to 50% of the cost (450-700€/sqm).

In return:

  • All projects have a strong focus on both affordability and high environment and energy-efficiency. Many of the projects have won awards for these aspects.
  • Non-speculative ownership of the apartments by the cooperative members. The building returns to public property when the agreement ends.

From lighthouse projects to a CH policy

  • Bilateral agreements with La Borda and Sostre Civic (2014 and 2015): for 2 pilot-projects, 33 units (La Borda, Princesa 49). To test the model in new housing and rehabilitation.
  • Public tenders (2016 and 2019): 8 projects, total 217 units. This was a difficult phase for both the municipality and the cooperatives who had to compete. The tendering instrument was not adequate.

New municipal procedure for affordable housing:

  • 2020: ESAL Partnership agreement signed between the City Council and the three umbrella organisations of all non-profit cooperatives and foundations, working in affordable housing (XES, Habicoop and Cohabitac) and the Association of Social Housing Policy Managers of Catalonia (GHS).
  • Public land is offered on 99-years lease to produce 1000 affordable homes in the next 10 years (probably before) in a Community Land Trust inspired model:
    • 40% cooperative housing: 8 projects, 296 units (Goal is 400 CH units in 10 years).
    • 60% social rental housing by foundations (600 homes in 10 years).
  • The three organisations open a call to their member organisations, review project proposals to see If they meet the ESAL criteria (technical, social, environmental) and they must agree with each other to propose only one project for each plot of public land. The municipality and GHS can accept or reject the propositions.
  • This process is faster and more aligned with the non-profit sector with the purpose of collaborating to create affordable housing solutions for all.
  • Framework Agreement with public banks (ICF and ICO) to provide 140 M€ in financing.
  • Revolving fund: once the cooperatives and foundations will have paid their bank loans and enter in a benefit phase through the rents of their members/tenants, 50% of the future net benefit is to be put annually into a revolving fund to support other affordable housing projects within the framework of the ESAL agreement through the municipal Community Land Trust.

Discussion with speakers

Discussion moderated by Dr. Lorenzo Vidal based on questions from the audience.

Are competitive public tenders a solution in some of your cities or other more partnership-oriented forms better fitted to CH?

Robert Temel, Vienna: The City of Vienna started the competitive tenders in 2011 and they take place from time to time. The model has positive results. There is no such thing as a Community Land Trust in Vienna, but the city has a land fund that sells land for social and collaborative housing. Buyers are limited profit entities, and they have to use the land forever for the purpose of affordable housing, so there is no need for a specific CLT to protect the land use.

There is not a lot of direct cooperation between the City administration and the civil society, and not as many CH projects, so this could still be improved in Vienna.

Jeroen Laven, The Hague: In the Netherlands, it’s also complicated to have tenders, and competition is mandatory, even for temporary use of public land. We hope to find a solution through a more flexible organisation than the municipal authority to manage the land and work with the CH groups to make the projects happen.

Javier Burón, Barcelona: Each country has obviously its own legal frameworks. In Barcelona, tenders were a nightmare, the municipality was sued, 20% of the plots are still frozen by a judiciary process, a lot of fighting between applicants, some private companies claiming to complying with the requirements tried to get plots of land. In Catalonia, it’s legal for cities to sign a single direct agreement with any NGO. But here the question is: what type of relation do we want to establish with the non-profit sector? Short term one-shot relations, or long-term relations diversifying the housing supply? We must develop framework agreements with guarantees of the public interest.

The idea is to foster that these collaborations get stronger, bigger, and more complex. In our case, public tenders are not adequate.

Could you give more details about the access to financing through public backup and revolving funds for Collaborative Housing?

Jeroen Laven, The Hague: For many organisations, it’s difficult to get money from the banks. The gap that banks leave behind when they give a loan for a housing project can be paid by the municipal budget and paid back to a revolving fund. We have to accept to take a certain risk so that if the CH project fails, the people will not get bankrupt and end up on the street.

Rebecca Bosch, Brussels Capital Region (Brussels Housing): In our case, at the beginning it was really difficult for the CLTB to get funding from banks. The formally recognising them in our legislation recently gave banks more security to lend them money. And the other help is the subsidies through the operating and investment grants which ensures the CLTB can follow their work.

To what extent is it possible to build affordable CH also on private land?

Rebecca Bosch, Brussels Capital Region (Brussels Housing): The region does not possess land, so the CLTB has to buy private land. Through the CLT mechanism the land becomes collective ownership, and the price of the land is taken out of the price of the dwellings.

Charlotte Grosdidier, Lyon, France: The municipality buys the land then it sells it at lower price for projects which involve social housing because we want to limit the price of the social housing.

Pierre-Charles Marais, France: Most of the CH projects are built on land that the resident’s groups can buy by themselves with their own resources. So, we often hear the stereotype that cohousing groups are only interested in the countryside, but in fact they do not succeed in buying land where the competition and prices are high. This is why public help should be concentrated on these areas where land is unaffordable. The CLT is of course a great instrument for that.

About the target groups, there were several mentions of mixed-incomes projects, low-income, how does this happen in practice to combine the group cohesion from cohousing with opening social origins, social housing waiting lists, etc?

Robert Temel, Vienna: In Vienna the projects are mostly in the framework of subsidised housing and are therefore affordable, but on the upper level of the “spectrum of affordable housing”. This is because in Vienna the social housing policy mixes on purpose lower and middle incomes to avoid social segregation. Many of the CH projects aim for a diverse composition of households. It is quite successful in achieving diversity of ages, occupation, countries of origin, but not so much in terms of educational level and income level. Many projects include one or two homes for refugees that are subsidised by the CH members, but it is more difficult to achieve a large spectrum of incomes in the CH group.

Pierre-Charles Marais, France: To ensure cultural and social diversity, you need to create specific conditions to make people aware of CH and how they can be involved in such projects.

Charlotte Grosdidier, France: The cooperative housing groups promote social diversity and are sensitive to accommodate people with lower incomes. They can have a mix between income levels and sometimes the wealthiest pay more than the poorest inside the cooperative. You usually also find senior people, people with disabilities. This diversity is very important.

Rebecca Bosch, Brussels Capital Region: Brussels is already a city with a very diverse population in terms of origins, so this is reflected in the CLTB’s membership. In the CALICO project, there were 3 non-profits associated to the project and each one has different conditions for people who could rent or become members: low-income people (CLTB), elderly women or single mothers with children (Angela D), intergenerational cohousing (Pass’ ge).

Jeroen Laven, The Hague: We work a lot with Housing Corporations which work with elderly vulnerable people. An interesting example we experimented with was a temporary use of a former ministry where we combined homes and helped to find jobs for asylum seekers and students. This was very successful, and we replicated it with cooperatives in projects we call “urban mix” with 50% of a specific target group and 50% of other social housing beneficiaries.

Javier Burón, Barcelona: In the municipality our housing policy is focusing 40% of social rent, 40% affordable rent, 20% leaseholds of public land. These are for people with different socio-economical groups, the cohousing groups are very much in the “affordable rental” groups. But today it is impossible to work with sectors from the social rental category in cooperative housing, because participating in a CH group requires investing time, money, knowledge, and relationships, which is not accessible for everybody. We can of course work to reduce that gap. For example, currently an average flat at market price costs around 400,000€ (difficult to find anything below 300,000€), and the cooperatives can produce for themselves flats that cost around 150,000€. This is affordable for many, but not yet social. The cooperatives themselves are very preoccupied by this. When they propose a project to the municipality, they propose that some of the units are social rent, other units for specific target groups. So, there is a will to create this social inclusion. Here the key is regional and national governmental support to complete the municipal effort made. We have succeeded to include the national level in an agreement signed recently.

The key resource in addition to land, financial support, and the other things that have been mentioned is mutual trust between the administration and the civil society movements. If the administration does not trust that the collaboration will lead to a better housing portfolio than no collaboration, or the civil society organisation does not understand the authorities must deal with a lot of legal rules and a complex environment, nothing will happen. We must build this trust and merge these worlds to create something complicated, but nice.

Q & A and Toolbox for Community-Led Housing

The Q & A and Toolbox can be read on this document. - pages 11 and 15