As a rationalist who had kids while within a deep community, I will say that only some of the community (that mostly said they wanted to stick around) actually stuck around after the kids showed up. I think there’s a whole series to be written about that, but I’ll sketch towards it now:
Parents schedules are different. If you really want to see them, you have to show up, not just invite them to your nonparent parties.
After a dozen invites that we don’t make it to, nonparents stop inviting us parents, and then we’re cut off. Even if we don’t show up, we appreciate the invitation—I have occasionally made it to a nonparent invitation, but only from those who persist in inviting me.
Immediately after the baby arrives, the best things to do to help parents are chores. Prepping and making food, laundry, cleaning, etc.
Now that the kids are old enough for a consistent bedtime, I’m probably best available to hang out at 5:30pm or 9pm, but not 8pm. The 9pm one relies on you visiting me, or my partner hanging out in case the kids wake up. (I love 9pm visitors). If you’re a nonparent who wants to help, you can always offer to hang out after the kids are asleep so parents can go out (if they’re not going to sleep by 10, which is pretty common, so don’t be surprised if that doesn’t work for many parents)
As a nonparent, expect to build familiarity with the kids over a handful of events before you can babysit. Kids warm up to adults just like people warm up to other people—often slowly.
Cohousing, in the US, is the term of art. I spent a while about a decade ago attempting to build a cohousing community, and it’s tremendously hard. In the last few months I’ve moved, with my kids, into a house on a block with friends with kids, and I can now say that it’s tremendously worthwhile.
Cohousings in the US are typically built in one of three ways:
Condo buildings, each condo sold as a condominium
Condo/apartment buildings, each apartment sold as a coop share
Separate houses.
The third one doesn’t really work in major cities unless you get tremendously lucky.
The major problem with the first plan is, due to the Fair Housing Act in the 1960s, which was passed because at the time realtors literally would not show black people houses in white neighborhoods, you cannot pick your buyers. Any attempt to enforce rationalists moving in is illegal. Cohousings get around this by having voluntary things, but also by accepting that they’ll get freeriders and have to live with it. Some cohousings I know of have had major problems with investors deciding cohousing is a good investment, buying condos, and renting them to whoever while they wait for the community to make their investment more valuable.
The major problem with the coop share approach is that, outside of New York City, it’s tremendously hard to get a loan to buy a coop share. Very few banks do these, and usually at terrible interest rates.
Some places have gotten around this by having a rich benefactor who buys a big building and rents it, but individuals lose out on the financial benefits of homeownership. In addition, it is probably also illegal under the Fair Housing Act to choose your renters if there are separate units.
The other difficulties with cohousing are largely around community building, which you’ve probably seen plenty of with rationalist houses, so I won’t belabor the point on that.