Superinsulated Geodesic Dome

Solar Collector, Dome, Driveway

The dome is for sale. Here's its listing on We've dropped the price from $250,000 to $199,000. No other house for sale in Fairfield has this particular set of advanced features:

  1. Insulation -- There's ten inches of spray foam insulation. The top of the dome is all closed-cell foam, for an R-60 "roof." Closer to vertical, it's open-cell under an inch or two of closed-cell, for R-40 "walls." Spray foam stops air infiltration more effectively than other forms of insulation, for a comfortable, draft-free home. Before the radiant floor was hooked up, two 1500 watt space heaters kept us warm in the coldest weather. This means the dome only loses around 10,000 BTUs/hour. That's extremely low for a house this size.
  2. Longevity -- The surface is covered in copper-colored Reinke aluminum shakes. Any house with asphalt shingles is a house with an expensive roofing job in its future. The Reinke slogan is "Shingle for the last time!" and with this dome that's already done. Take a look at Reinke's Hail and Tornado page for further convincing.
  3. Strength -- What good are shingles that won't blow off if the whole house blows over? Spheres are stronger than cubes, and a partial sphere made of triangles is much stronger than that floppy collection of parallelograms known as a 2x4 stud wall. Domes regularly survive tornadoes, hurricanes, and straight-line winds that destroy conventional houses.
  4. Health -- Iowa has the nation's highest radon levels, but this house has a radon pipe. It tested well below 4 pCi/L with the doors and windows closed and the ventilator turned off for a week. Normally, the Energy Recovery Ventilator would be delivering fresh air, expelling stale air, and further reducing radon levels. Another health benefit: solar heat with electric back-up cannot cause carbon monoxide poisoning.
  5. Beauty -- This is of course subjective, but we've had many compliments on the dome's appearance, both inside and out. It feels very uplifting to live in a home with high ceilings that curve like the sky.

Here's a page about the early stages of the building process, some construction photos, and more on the solar heat.

The front door and driveway:

Front Door

The living room's flooring is Marmoleum Click, color African Desert.

Front Door

The west end of the living room becomes the kitchen:


The loft in art gallery mode:


Marcia hand-glazed tiles and installed them behind the kitchen sink and in the shower:

Kitchen Tiles

Shower Tiles

Steve's studio, which we're calling a bedroom, is 211 SF including the closet and half bath:

Steve's Studio

Marcia's studio, which we're also calling a bedroom, is 295 SF including the closet:

Marcia's Studio

An investigation into local real estate conventions suggests that the 9' x 14' room we actually used as a bedroom can, in fact, be counted as a third bedroom. While it has no closet or window, it has a fresh air duct and two doors for emergency exit. When you open the doors, you see windows:


Floor Plan. The shaded area is the loft.

dome floor plan

Double-wall construction minimizes thermal bridging:

Fisheye View of Dome Interior

The dome at dusk:

Dome at Dusk

More photos at our listing on