First, I doubt this is an actual earthship which means it isn't so delicate.
Second, I bought an earthshelter home last year that was built in the early 80s. I would say it needed some tlc. Thankfully that just meant some general mintenance as it hasn't been lived in in a while.
I would be most concerned with water leakage. Also ventilation. Our home suffers from high humidity and radon, which would both be helped with better ventilation, which we are working on.
