Here is a simple Zome-dome design. It is half of a 6b3
icosahedron, with the top raised up to form a cupola, and a small crawl-through
entry way. It is roomy enough for a very small rocking chair, table,
reading lamp, and bean-bag chair. You need quite alot of b3s.
It took an hour for two people to assemble it.
Here it is again, in the evening, after covering it with sheets, with
a light on inside: