First let me say I know this probably wont work for many reasons but just throwing it out there for discussion sake. Maybe there are more ideas out there that I haven't thought of.
What if there was a property that was set up for a small group of mustachians to live on in retirement that was designed from the ground up to be as low cost as possible. I don't know if it would be a condo structure or separate cottages or whatever. But certain items, utilities, and resources could be shared.
Ideas for saving money may be:
Shared TV/internet service
Solar panels (structures built with south facing roofs), or wind turbines (if cost savings would be realized)
Shared garden area for food supplement
Shared lawn care equipment/garden tiller
Some other things possible I guess. I'm not sure how the property ownership would be handled but I wouldn't want one person to profit more than the others unless he was the original property owner and he was being paid a low rent for his donation to the cause. Also not sure how to handle a couple deciding to move out or passing away as far as finding replacements.
Some cool ideas would be to have a gazebo/fire-pit or pole structure for family get togethers.
I know that it's probably asking a lot for certain personality types to be able to tolerate each other and this would mostly depend on finding the right (like minded) people.
