I am a member of a hiking club that has a lodge in the Sierras. The site has an abandoned water tank which we thought would make a great cabin. Here's the design & rendering I did. The foundation is existing concrete, and the wood is the original redwood staves, refinished. There's a roof deck which drains to copper scuppers. Rain chains direct the runoff to cisterns which feed planters. A composting toilet is housed in the attached Cor-Ten silo.