So I read the RSA report on cohousing - see here - and my main take-away is that it wasn't really about cohousing. There's lots about what is broken in the UK housing market - in particular, the lack of actually affordable (as opposed to "affordable", now a term with special meaning that specifies a discount from overblown market rents rather than a relationship to disposable income), and the poor terms and conditions that apply to renters but not so much to mortgage buyers. There is quite a lot discussion about forms of tenure, with particular emphasis on mutual ownership, rental co-ops, a community land trusts.
That's all very interesting (really, it is) but most of the report misses the point about cohousing, which is that it is form of occupancy, not a form of tenure. The cohousing community where I live, and most of the others in the UK and the US, is primarily based on owner-occupancy, though there are some private renters (living in homes owned by individuals, not the community or any other institution) and some lodgers. The tenure is more or less bog-standard leasehold that you'd find in many blocks of flats. In Northern Europe there are lot more rental-based cohousing communities, with the community (or a housing association) acting as the landlord.
The distinguishing feature of the occupancy is really the self-management. Other developments have shared facilities. It's a common feature of high-end developments (pool, gym etc.). Old-style US condominiums have residents' association rooms and facilities, and shared laundries seem to be common in US apartment blocks (though not in British ones). The new commercial 'co-living' set-ups like The Collective have them too.
The difference is that in co-housing these are managed and maintained, and cleaned, (for the most part) by the residents themselves, and it's the organisation of this that means that people are necessarily entangled and involved with each other. Not everyone is equally involved, but it seems to be true that the more you put in, the more you get out - at least in terms of loneliness reduction.
Our community has frequent (thrice-weekly) communal meals, prepared and cooked by community members through a rota, to a rolling meal schedule, in a communal kitchen and dining room that is beautifully maintained. The eating together is important (though not every cohousing community does it), but it's the self-management - the rotas and the inevitable shift swaps, the menus, the food buying - that keeps people entangled with each other. The upside of cohousing, the connection with other people, is exactly the same as the downside - that you are inextricably bound up with other people.
When my partner and I tell our friends about it, they often react that they wouldn't like to have all of those obligations...and they might be right. In one sense, the people in cohousing are just like everyone else. There isn't a common ideology or philosophy. Not everyone is particularly generous or self-less. Some people are involved with wider communities, some aren't. What distinguishes them is their ability to tolerate these obligations, and that level of entanglement with other people and need to take the views and preferences of others into account. I suspect that this is a not such a common characteristic, especially in Britain, especially now. If I'm right, then cohousing won't be a cure for loneliness, at least for many people - though it is a good vehicle for those who are that way inclined. It's probably worth noting that even in those Scandinavian countries where it's well established and relatively easy to establish the proportion of the population that lives in cohousing remains below 5%.