My project has involved neighbors, family, and even a few contractors. But unlike a barn built from scratch there are a lot of random bespoke tasks. Many of them require judgement and experimenting to make it work. Sadly the property was neglected a long time, and poorly built in the first place. Bulldozing and having a new house professionally built would've been faster, produced a better outcome, and only been moderately more expensive--in hindsight.

In the old world you would have the distinct privilege of bringing this experience to your community. No naive youth can afford even a “starter” house for you to help them rebuild.

There’s Habitat for Humanity which I think would fit this description.

I’ve personally never involved myself with it but over the last few months the group built a modest house on a small lot next to my ex-spouse’s place. Every weekend I saw a group of folks (ranging in age from early 20s to retirement) there building, chatting and generally being very friendly with one another. Really cool to see.