Growing up as a Jehovah's Witness, I was a volunteer on many "quick builds". Witnesses typically build a kingdom hall using volunteers. Of course they pay to have the concrete foundation poured or a more specialized regional volunteer crew does the on site work. The rest of the structure goes up in a 3 day weekend and is painted, carpeted, with all furniture and amenities by Sunday. I think they are a little slower now than they used to be, like a two weekend stretch due to inspections and code. There are witnesses that do all of the required licensed professions. Like my old man is a Wiremen, so I always got stuck in the attic and crawl spaces running wire.
I'm not in that world any more, but I would gladly spend a few weekends a year helping build someone a few houses in a similar style in exchange for building my own home when it is my turn. Like what if it was an open list where you could build some credible skills by showing up and trying to work in one trade, but have around 50:50 chance of getting that assignment. If you already have a licensed skill or trade, your volunteer time is worth more. Anyone is welcome to show up to builds in their region. Your volunteer time is how you move up the list. If you have property, supplies, and can afford the time, you could volunteer every weekend to expedite your own build on the regional list.
In my experience, the social connections from this kind of experience are so strong that many people will continue to volunteer and show up without any expectations whatsoever.
IMO, public forestry land and resources should fall into this kind of system. Even the majority of your supplies should be derived from the same system.
Anyways, that is just my take on what is possible.