Cohousing is a new type of residence which was first appeared in 1960s in Denmark. (Its basic features have been discussed in the blog THE CO-HOUSING COMMUNITY: An Attractive Living Model Based on Social-Neighborhood, Affordability and Sustainability ) This blog will focus on the development model of Cohousing community, and analyze and compare these development models in terms of development process, financial strategy, residents’ participation and sales approach in order to provide some reference for everyone`s study of this aspect.
The construction of early cohousing community was mainly by self-purchase land of residents, and then gradually promoted the design, construction, capital management and other matters during the negotiation process. Then, with this concept gradually accepted by mainstream society, the composition of residents has gradually extended from the middle class to all sectors of society (including low-income groups). Meanwhile, Cohousing has developed a number of new development models in the process of evolution. The participation degree and method of residents have been improved as well. At present, the development model of Cohousing community mainly has following forms:
1. Project Model
Most of early Cohousing community use Project Model. In this mode, some community members form a core group to participate in the development process of all transactions. That is to say, from site selection, setting target, community design, project financing to marketing, management and other aspects, all of these things are completed by residents themselves(See figure 1) . High risk and high demand for members are the main features of the model. As it requires the members to have sufficient cash and credit capacity, as well as the knowledge of development and construction, and to make the right decisions at the right time.
Figure 1: Hareskov Cohousing by Jan Gudmand-høyer, which is composed by 12 houses around a common house (from: http://www.samenhuizen.net/cohousingdk/deel2/II21.htm)
Through this kind of development process, the members can share a common experience, which will help them to manage the community better in future life. In a sense, Project Model is the most consistent development mode with the original intention of ‘Cohousing’ concept. Communities in early Northern Europe mostly adopted this strategy, however, due to the complexity of whole process, the proportion of this type of community is gradually decreasing.
2. Lot Model
Project Model is often time consuming, to reduce financial risks and shorten construction time, Lot model has been gradually explored basing on the basis of the existing. This model is developed by the non-profit development team who is responsible for purchasing land, selecting architects and building houses. In this mode, the land is divided into a number of plots, and set aside some of them for public facilities, which belong to all members of the community. The remaining plots are sold to individual members who are required to undertake the construction funds and pay a certain proportion capital for the construction of public facilities at the same time.
This model allows some residents to participate in the late development stage, when the individual plots are ready to sell or develop further. Like Swan`s Market Cohousing adopted this development model(See figure 2, 3), members gave up a part of decision-making power, but can speed up the process and reduce financial risks, as well as tending to build more personalized houses.
Figure 2: Swan’s Market Cohousing (from: http://www.meetup.com/ebcoho/pages/Swans_Market/)
Figure 3: Basic information of Swan’s Market Cohousing (from: https://stitchdesign.wordpress.com/2011/01/26/swans-market-cohousing-community/)
3. Expansion Model
“Cohousing” is not restricted to the construction of new community. In addition to the newly-built communities (including the transformation of current structure/reuse) throughout the process of development, there appears refurbished housing, namely Retrofit Cohousing. Retrofit cohousing is not to reconstruct the current house, but to buy nearby estates, then to remove the fences between the yards and finally build the public facilities. 
N Street in Davis, California is a typical instance of the above mode. Fig. 4 demonstrates the registration chronology of N Street residents. This mode plays an effective role in the recycling proposals of old facilities and buildings across the US and Canada, and it has brought mew vitality to old picture of suburb and downtown. 
Figure 4： The registration Chronology of N Street Residents (from: http://www.slideshare.net/samenhuizen/sh-20141120-mol)
4. Streamlined Model
With the popularity of “cohousing”, streamlined model comes out as a for-profit development mode, and the property developers are in charge of the development, funds, site as well as unit designing. Compared with traditional development pattern, this procedure reduces the participation of residents and lowers their “sense of community”. Like Pleasant Hill Cohousing, which is located in North California, adopted this kind of development model(See figure 5). In the simplified version, professional consultants together with property developers work with the core group to lower the risks of financing and shorten the development cycle.
Figure 5: ‘Milestone’ of Pleasant Hill Cohousing (from: http://phch.org/aboutus.htm#facts)
Currently, traditional liabilities assumed by residents would be accomplished by the developers. The developers of Pleasant Hill, for instance, construct renewable communities based on “cohousing” and principals of organic design, renewable building as well as personal values and ideas of community.
“Cohousing” community, as a gradually developed pioneering community over a half century across the Europe, US and the Pacific rim, adopts resident-oriented, government, consulting firms and architects-supplemented development pattern. This kind of community has developed several basic strategies from site selection, designing, construction to hotel management, and accumulated enough experience in the funds supervision, project operation, and conflict resolution. All of the above could act as good references in our designing cohousing community or others.
Lindsey L G．Cohousing：Its Characteristics，Evolution， and Emerging Typologies．Cincinnati：Graduate School，University of Cincinnati，2005．
Fromm D．American cohousing：The first five years．Journal of Architectural and Planning Research，2000，17（2）：94-160．
Graham M．Sustainable Community：Learning From the Cohousing Model．Victoria，BC：Trafford Pr，2005：10-115．
McCamant K，Durrett C，Milman D．Bofaelleskaber to cohousing．Communities，2000，106：60．