Also known as ‘co-op housing’, it is a kind of non-profit housing in which residents are actively and equally involved in making the decisions that run the community they live in. There are co-op communities for only seniors with a pre-determined minimum age criterion, there are some for just families, and yet others that are open to any age group. The members do not usually hold any ownership in the property. They pay monthly rent that may be income-based and possibly less than market rates depending on their situation and the rules of the co-operative.