Baggywrinkle: and for ventilation, check this out from the rubicon. These guys actually do everything they talk about
http://www.alpharubicon.com/basicnbc/safefanwar.htm
Safe Room Squirrel Cage Fan* Fan in a can.
and this.. Super Strong Geodesic Dome Frame tuttle tuff shelters
ttp://turtletuffshelters.com/
Two models: Galapagos-24ft. & Snapper-16ft.
“Galapagos-24” -9ft high, 24ft dia, 452ft/sq
-High R Value insulation, floor, stove, solar lighting, clear hot house covers avail.
“Snapper-16” -8ft high, 16ft dia, 200+ ft/sq
-Same great features as the Galapagos-24