A cohousing community is a type of intentional community composed of private homes supplemented by shared facilities. The community is planned, owned and managed by the residents – who also share activities which may include cooking, dining, child care, gardening, and governance of the community. Common facilities may include a kitchen, dining room, laundry, child care facilities, offices, internet access, guest rooms, and recreational features.
In describing New York City's first co-housing project, a New York Times article said co-housing "speaks to people who want to own an apartment but not feel shut off by it, lost in an impersonal city."
The modern theory of cohousing originated in Denmark in the 1960s among groups of families who were dissatisfied with existing housing and communities that they felt did not meet their needs. Bodil Graae wrote a newspaper article titled "Children Should Have One Hundred Parents," spurring a group of 50 families to organize around a community project in 1967. This group developed the cohousing project Sættedammen, which is the oldest known modern cohousing community in the world. Another key organizer was Jan Gudmand Høyer who drew inspiration from his architectural studies at Harvard and interaction with experimental U.S. communities of the era. He published the article "The Missing Link between Utopia and the Dated Single Family House"  in 1968, converging a second group.
The Danish term bofællesskab (living community) was introduced to North America as cohousing by two American architects, Kathryn McCamant and Charles Durrett, who visited several cohousing communities and wrote a book about it. The book resonated with some existing and forming communities, such as Sharingwood in Washington state and N Street in California, who embraced the cohousing concept as a crystallization of what they were already about. Though most cohousing groups seek to develop multi-generational communities, some focus on creating senior communities. Charles Durrett later wrote a handbook on creating senior cohousing. The first community in the United States to be designed, constructed and occupied specifically for cohousing is Muir Commons in Davis, California. Architects, Kathryn McCamant and Charles Durrett were responsible for the programming and the design of the site plan, common house and private houses.
There are precedents for cohousing in the 1920s in New York with the cooperative apartment housing with shared facilities and good social interaction. The Siheyuan, or quadrangle design of housing in China has a shared courtyard and is thus similar in some respects to cohousing.
Hundreds of cohousing communities exist in Denmark and other countries in northern Europe. There are more than 120 operating communities in the United States with more than 100 others in the planning phases. In Canada, there are 11 completed communities, and approximately 19 in the forming or development phase (see ). There are more than 300 cohousing communities in the Netherlands (73 mixed-generation and 231 senior cohousing), with about 60 others in planning or construction phases.  There are also communities in Australia (see Cohousing Australia), the United Kingdom (see UK Cohousing Network http://www.cohousing.org.uk for information, Threshold Centre Cohousing Community http://www.thresholdcentre.org.uk/ offers training), and other parts of the world.
Cohousing started to develop in the UK at the end of the 1990s. The movement has gradually built up momentum and there are now 14 purpose built cohousing communities. A further 40+ cohousing groups are developing projects and new groups are forming all the time. Cohousing communities in the UK range from around 8 households to around 30 households. Most communities are mixed communities with single people, couples and families but some are only for people over 50 and one is only for women over 50 years. The communities themselves range from new developments built to modern eco standards to conversions of everything from farms to Jacobean mansions to former hospital buildings and are in urban, rural and semi- rural locations.
Because each cohousing community is planned in its context, a key feature of this model is its flexibility to the needs and values of its residents and the characteristics of the site. Cohousing can be urban, suburban or rural. The physical form is typically compact but varies from low-rise apartments to townhouses to clustered detached houses. They tend to keep cars to the periphery which promotes walking through the community and interacting with neighbors as well as increasing safety for children at play within the community. Shared green space is another characteristic, whether for gardening, play, or places to gather. When more land is available than is needed for the physical structures, the structures are usually clustered closely together, leaving as much of the land as possible "open" for shared use. This aspect of cohousing directly addresses the growing problem of suburban sprawl.
In addition to "from-scratch" new-built communities (including those physically retrofitting/re-using existing structures), there are also "retrofit" (aka "organic") communities in which neighbors create "intentional neighborhoods" by buying adjacent properties and removing fences. Often, they create common amenities such as Common Houses after the fact, while living there. N Street Cohousing in Davis, CA, is the canonical example of this type; it came together before the term Cohousing was popularized here.
Cohousing differs from some types of intentional communities in that the residents do not have a shared economy or a common set of beliefs or religion, but instead invest in creating a socially rich and interconnected community. A non-hierarchical structure employing a consensus decision-making model is common in managing cohousing. Individuals do take on leadership roles, such as being responsible for coordinating a garden or facilitating a meeting.
Cohousing communities in the U.S. typically rely on one of three existing legal forms of real estate ownership: individually titled houses with common areas owned by a homeowner association, condominiums or a housing cooperative. Condo ownership is most common because it fits financial institutions' and cities' models for multi-unit owner-occupied housing development. U.S. banks lend more readily on single-family homes and condominiums than housing cooperatives.
Cohousing differs from standard condominium development and master-planned subdivisions because the development is designed by, or with considerable input from, its future residents. The design process invariably emphasizes consciously fostering social relationships among its residents. Common facilities are based on the actual needs of the residents, rather than on what a developer thinks will help sell units. Turnover in cohousing developments is typically very low, and there is usually a waiting list for units to become available.
In Europe the term "joint building ventures" has been coined to define the form of ownership and housing characterized as cohousing. According to the European Urban Knowledge Network (EUKN): "Joint building ventures are a legal federation of persons willing to build who want to create owner-occupied housing and to participate actively in planning and building."
- McCamant, Kathryn; Durrett, Charles. Creating Cohousing: Building Sustainable Communities, New Society Publishers, 2011, ISBN 978-0-86571-672-8.
- McCamant, Kathryn; Durrett, Charles. Cohousing: A Contemporary Approach to Housing Ourselves (2nd Edition), Ten Speed Press, 1994, ISBN 0-89815-539-8.
- Meltzer, Graham S. "Sustainable Community: Learning from the Cohousing Model." Victoria, B.C.: Trafford Press, 2005, ISBN 1-4120-4994-6.
- ScottHanson, Chris; ScottHanson, Kelly. The Cohousing Handbook: Building a Place for Community (2nd Edition). Gabriola Island, B.C.: New Society Publishers, 2005 ISBN 0-86571-517-3.
- Williams, Jo. Designing neighbourhoods for social interaction: The case of cohousing, " Journal of Urban Design," 2005, Vol.10, No. 2, 195-227.
- Cohousing definition (American Heritage Dictionary of the English Language: Fourth Edition. Houghton Mifflin 2000).
- McCamant, Kathryn; Durrett, Charles. "Cohousing: A Contemporary Approach to Housing Ourselves." Berkeley, Ca.: Ten Speed Press, 1994.
- Durrett, Charles. "Senior Cohousing: A Community Approach to Independent Living." Gabriola Island, B.C.: New Society Publishers, 2009.
- "The Real Park Slope Co-op". The New York Times, Robert Sullivan, 1, 2009.
- Graae, Bodil. "Børn skal have Hundrede Foraeldre", "Politiken" [Copenhagen], April 1967.
- Gudmand-Høyer, Jan. "Det manglende led mellem utopi og det foraeldede en familiehus." "Information" 26 June 1968
- McCamant, Kathryn; Charles Durrett and Ellen Hertzman (1994). Cohousing: A Contemporary Approach to Housing Ourselves (2nd ed.). Ten Speed Press. p. 208. ISBN 0-89815-539-8. "Muir Commons is the first cohousing community to be built in the United States."
- Norwood, Ken; Kathleen Smith (1995). Rebuilding Community in America: Housing for Ecological Living, Personal Empowerment, and the New Extended Family. Shared Living Resource Center. p. 111. ISBN 0-9641346-2-4. "Muir Commons was the first CoHousing community to be built entirely new in the United States."
- "Community Addresses in The Netherlands". Federatie Gemeenschappelijk Wonen.
- EUKN, Guideline of Joint Building Ventures in Hamburg
|Wikimedia Commons has media related to Cohousing.|
- Schemata Workshop - Cohousing Research
- Cohousing Australia
- Coho/US list of U.S.Cohousing communities
- Communities Self-Identifying as "Uses Cohousing Model" in FIC's Communities Directory
- Barry Yeoman, Rethinking the Commune, AARP: The Magazine
- Eco-Village and Cohousing Association of New Zealand --EVCNZ
- First (and only completed) Cohousing community in New Zealand
- Canadian Cohousing Network
- Toronto Cohousing Canada
- Threshold Centre - Established Cohousing Community and Cohousing Education Centre in Dorset, UK
- LILAC - New cohousing community in UK
- Lancaster Cohousing - New Cohousing Community in UK
- LoCo cohousing Senior cohousing developing in Colchester UK
- Landelijke Vereniging Centraal Wonen (LVCW) - Cohousing Association of The Netherlands
- Centro Social de Convivencia para Mayores Trabensol - Cooperative housing for seniors in Spain
- Google Videos on Cohousing (Several videos at Cohousing locations and news items)
- Voices of Cohousing: Rebuilding villages in the city (Documentary)
- Cohousing Interviews with Charles Durrett (Several videos about Cohousing)