Basic hexagonal building has six 8’x8’ walls (12 4’x8’ full sheets of plywood), six triangular roof panels
(six full sheets of plywood cut on diagonal (zero waste), six 8’ studs, six 8’ rafters,
with folded plate corners & ridges, double 4’ swinging doors, raised floor area = 166 sq.ft.
with shake roof, 1982 cost = $9/sq.ft.
Plans $25

Variations of 1162 sq.ft. inside hexagonal module complex of pole/stucco/foam sandwich construction,
with self-heating solar thermo-siphon thermal mass heat storage.

BUILDING MATERIALS COST ESTIMATES FOR SELF-HEATING STUCCO/FOAM SITE-BUILT SIP ~ Including foam, ferro-stucco, metal roofing, skylights, concrete floor, 400 ft. natural draft heat transfer ducting, thermal mass isolation membrane ~ (Not included poles, windows, doors, electric, plumbing, hardware, labor, etc.)  2007 material costs = $15,000 = $12.90/sq.ft.  Wall material costs, for 6” R30 foam insulation, wire, stucco, finish color coat 2 sides = $4.50/sq.ft.

Detailed Plans $45

Many variations are possible: 
 
•variations in room size and ceiling height
•more and smaller poles in ceiling
•with or without central ridges
•from one to seven modules
•remove inside walls, 2nd story
•air ducting behind poles in corners
•wiring and plumbing in grooves in foam