Hi, I am new here, but not new to self sufficiency. It is nice to see activity here. I am newly 42, and living. I have a lot of building, fabricating, and repair experience so feel free to question me. Yes, I have built underground before and have experience. Largest underground project was 5000 square feet, and is still holding up well after more than ten years. Have done farming, animal husbandry, strong agricultural background. I am here to learn and help others learn. I am also considering starting a group of like minded individuals for a retreat endeavor.