There are two general lines of thinking: One is to go far far out (e.g. into the arctic) and use distance to separate from broken culture (and have a lot of legal/regulatory autonomy because the nearest cop is 1000 miles away).
The other is to just create a community anywhere but simply isolate the culture. Amish and Hasidic Jews have shown that this does work.
Going far out creates urgency to solve certain problems which staying close to "civilization" does not. But staying close is generally a lot easier.
One could fairly ask "why re-invent the Amish?" and the Amish have really figured this out. But what the Amish have not figured out (and don't seem interested in) is how to on-board anyone else. So they're all set but the rest of us are still screwed.
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One interesting question is how a settlement should interface with the government. If most of the people living there are not making any formal income, there's no reason not to sign everyone in the settlement up for SNAP and Section8. The income to the settlement organization would be immense.
I think one thing the Amish got very right is that car ownership creates more problems than it solves. It's hard to tell everybody that they need to sell their car on day 1, but building a walkable community in a place with river access only will help move people away from using their car. Also, river access only puts a limit on people coming in to snoop around and potentially make trouble.
Personal electronics (phones, computers, TVs) PROBABLY need to simply be forbidden on the location. Designated office areas may be appropriate for computer usage, but phones are just a short road to slop-scrolling...
In place of TV and such, there should be a LOT of communal rituals and activities which take place.
A communal currency is practically obligatory, and I think that (to the extent possible) there should be no clear exchange rate. If there's a store on site selling food for SNAP EBT, that food would obviously need to be priced in dollars, but things like ferry boat transport, hot meals, and a haircut at the community barber would better be offered exclusively in the community currency.
Something to avoid is people bringing drugs and goyslop from outside of the community and selling it to community members. Making the community currency something that cannot easily be exchanged, is a feature.
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IDEALLY, one would encourage a different language inside of the community. Being bilingual is a super-power because you are able to switch between the Big Toxic Culture language, and the Family / Community Language which creates a clear distinction between talking to Safe People and talking to strangers (probably having toxic culture).
There's a possibility that China would be willing to co-sponsor such a community project if the language chosen for the community was actually Chinese.
When you build a community off-grid, one of the biggest cost drivers is energy.
Energy is non-negotiable, it is THE core element of any country/city/group of people. If the settlement is in a normal populated location, then you can use solar panels with supplementary wood-gas based electric generation in winter.
If the settlement is in the arctic, the sun is absent for nearly half the year and if there are forests, they are slow growing. So realistically you have three options: Locate on top of a gas well, locate on top of volcanic geothermal, or develop nuclear energy.
Energy is something you can never have enough of.
If you're powering with solar and wood-gas, you want to dig a pool (with insulated liner and lid) for storing thermal energy. In the summer when your solar panels are over-producing, you'll be running air source heat pumps to push heat from the (warm) outside air into the pool water. The pool insulation will trap the heat until winter, when power is scarce. You then heat buildings and hot water using "ground source" heat pumps which, rather than cycling liquid through the ground, instead draw from the pool - therefore they are extremely efficient.
An olympic size swimming pool holds 2.5 million liters of water, water energy storage is 1.16 watt-hours per degree C, so ranging between 0C and 40C (104F) you can store 116,000 kWh of energy - the same as 11,000 liters (3,000 gallons) of heating oil.
You definitely don't want any gas stoves or appliances. You need electricity, so solve electricity 100% and then use only that.
A big open question when you talk about building an intentional community in an already populated area, is how involved do you want to be in your local government?
If you have no involvement at all, then you risk regulatory attack. Deep involvement allows you to most likely take control - but that introduces a different problem because now you are likely to draw the hatred of the outside community - who may eventually manage to wrestle control away from you, and will end up banning you entirely.
Libertarians in New Hampshire and Jews in the US are a bit in this tiger-by-the-tail scenario where they actually have pretty much seized control, but the rest of the population is irate enough that if they ever lose it they're probably going to be expelled en masse.
I think the right answer is to aim for control - but also to *extend* the advanced political decision making system to members of the outside community, roughly by going around like Jehovahs' Witnesses and knocking on doors - but with the mission of learning their needs, wants and feelings, to help that person feel understood, and integrate their needs into the master plan. In the ideal case, you gain another voter who is not part of the commune.