I agree that the cohousing idea give us a meaning of sustainable, affordable and social living style. When living in cohousing, the shared facilities will create a way for residents to communicate with each other. And the layout of cohousing scheme have a strong way to connect these houses together. So it is true that the suitable scale of cohousing is 20~30 household.
In addition, the economic way to build cohousing is successfully attract low-income people to live in here, as they do not have enough money to buy a big house, but in cohousing, they can own a house and share additional space with others. It make a sense of meet the need of low-income people.
In the sustainable aspect, in the case that Guan Wang mentioned, residents will provided recycling equipment for collect the waste and organize some activities that promote sustainable living style. Because they already use shared equipment and facilities, I think it also a way to reduce the environmental effect. So cohousing is suitable for who want to reduce the effect of environment.
I am surprise that nowadays, there are a lot of cohousing cases and each case have its own value for us to learn. I think even though we do not live in cohousing, but the value of cohousing can use in our neighbourhood design and as a consideration of living style.