Behind the Wall
Considering the financial challenges of buying materials, we looked at the inside of the cave as our next option. Inside the cave, we already had a roof, walls, and a solid floor, as well as some plumbing and electrical left over from its previous businesses. Taking advantage of so much structure already in place would cut our materials costs significantly.
This plan involved putting a simple mezzanine structure in place, with offices and a kitchen below, and our residential space above. All of this would go in the space behind the wall, in what is now the middle chamber.
With this plan we faced the challenge of using materials resistant to humidity. With a natural humidity level around 95%, the basic structure needed to hold its integrity without growing mold even if the power were to go out while we were away.
This structure would require building almost entirely with metal and concrete. We had a decent collection of carpentry tools, but no skills or tools for working with metal. Plus, anyone can research code and figure out load calculations for wood structures. Building a metal structure takes an engineer.
After careful consideration of the structural requirements and high quotes on dehumidification and ventilation, we scrapped the mezzanine plan.