The standard seven inch thick (R-28) expanded polystyrene insulation (E.P.S.)  in the American Ingenuity 22′ thru 48′ dome building kits can be upgraded to nine inch thick (R-36) E.P.S.  See below for pricing.  To view the detailed data and characteristics of E.P.S. insulation, please click on Panel Composition and scroll down the page to view the EPS data.

Cold northern climates like Vermont and Wisconsin, etc. are appropriate areas to build Ai dome kits with the thicker 9″ (R-36) insulation. If a 45′ or 48′ dome’s insulation is upgraded, your shipment will require two semi-trucks for delivery.  The Ai dome with 7″ E.P.S. will easily outperform conventional housing with 11″ thick fiberglass insulation. Instead of purchasing thicker insulation from American Ingenuity consider applying the money you would have spent for the thicker insulation to purchase thermal coverings for windows, triple paned windows and insulated doors.

E.P.S.- Expanded Polystyrene Insulation

E.P.S. is frequently mistakenly referred to as “Styrofoam”. Although they both come from the same “base” material, polystyrene, the two products differ in many respects. “Styrofoam” is the registered name of Dow Chemical Co. and refers to the extruded polystyrene insulation product produced and marketed solely by that company. “Styrofoam” is generally blue in color and has a minimum density of about 1.80 pounds per cubic foot. It has a different cell structure (like hollow bubbles) and has a marginally lower better R value, but is considerably more expensive, not only per board foot but even more so on a “cost per R” basis. E.P.S. is available from more than 100 manufacturers throughout the country in a variety of sizes, densities and forms. “Styrofoam” is only available from one company in a more limited range of sizes.

Seven inches of sturdy, rigid R-28 expanded polystyrene (E.P.S.) insulation forms the core of each American Ingenuity component panel. This insulation is permanent, chemically and thermally stable, and resistant to mildew, provides no nutritive value to animals, plants, microorganisms, is non-irritating to skin, and is Chlorofluorocarbon (CFC) and formaldehyde free. This E.P.S. insulation will not rot, shrink, absorb moisture, compact, or deteriorate due to age or weather. It also acts as a vapor barrier for your home, providing stable performance year after year.

The E.P.S. that Ai uses is sometimes referred to as bead board and sometimes incorrectly referred to as Styrofoam (Styrofoam is the trade name for extruded polystyrene manufactured by Dow Chemical Co). Ai does not use Styrofoam.

American Ingenuity uses the one pound per cubic foot density, closed cell E.P.S. which has a thermal resistance (R-value) of 4.17 per inch of insulation at near freezing temperatures. This also explains why it is a very common insulation used in housing and sold at hardware stores. Ai uses the 7” thick E.P.S. which has an R-value of about 28.

Ai chose the expanded polystyrene over the extruded polystyrene because the extruded polystyrene is almost twice the cost with only a slightly better R-value.

When should you purchase the 9″ thick E.P.S.? If you have five or more days a year where the temperature reaches zero degrees then you may want to purchase the thicker 9″ insulation. If you have hotter days than most climates, we leave it up to you whether you need the 9″ thick E.P.S.. On the price list go to the Building Options and look down the list for 9″ Insulation.

Ai does not recommend that you purchase the 11″ E.P.S. insulation unless you live in a severe climate like the Northwest Territory of Canada.

Insulation Comparisons:

  • 2×4 solid wood with 3 1/2″ fiberglass is about R-8.
  • 8″ Concrete Block, with 3/4″ air, 3/4″ Celotex is about R-9.
  • 2×6 Solid wood construction with 5 1/2″ fiberglass is about R-11.
  • 2×4 solid wood with 3″ urethane is about R-13.
  • 7″ E.P.S. insulation is R-28 and is comparable to 11″ of fiberglass insulation.
  • 9″ E.P.S. insulation is R-36.
  • 11″ E.P.S. insulation is R-44.

American Ingenuity’s component panels for the 22′  thru 48′ domes includes the R-28 insulation and most of the steel reinforced concrete exterior finish and all the interior shell wallboard. Typically, in wooden domes you will likely have to purchase the insulation, wallboard and roofing materials for extra costs.

2015 Pricing For Thicker 9″  E.P.S. Insulation
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call for pricing


If you upgrade your 40′, 45′ or 48′ dome with 9″ EPS more semi-trucks will be needed for delivery.  The 40′ or 45 ‘ & the 48’ kit will require two trucks for delivery. All Kits whose insulation is upgraded are considered Specialized Orders and are custom made for that Buyer.  These orders require a 50% deposit to start manufacturing.  If the specialized order is cancelled any payments made are non-refundable.

Q: Why are your dome homes so energy efficient?
You can save 50-70% on heating and air-conditioning costs with your American Ingenuity dome over a conventionally built home. Some of the reasons for this superb energy efficiency are:

  • Super insulation that does not degrade with time, moisture, or compaction.
  • Spherical shape means reduced exposed surface.
  • Airtight exterior virtually eliminates energy leakage.
  • Solid thermal envelope.
  • Uniform R-value. The insulation is not interrupted with structural members (e.g. 2X4’s roof trusses). The only breaks are for doors and windows.
  • Downsized heating and cooling equipment.

Your kit comes with lifetime R-28 E.P.S. insulation or if you choose, thicker R-36 E.P.S. insulation is available. Even in cold climates, you may find that a single ventilating wood stove can heat a smaller dome (22′, 27′ or 30′) will provide all the heat your home will need. Larger domes need a centralized ducting system or mini-split ductless unites to disperse the heated or cooled air throughout your dome.


The Expanded Bead Polystyrene (E.P.S.) Insulation that American Ingenuity utilizes is seven inches of sturdy, rigid R-28 modified E.P.S. insulation that forms the core of each component panel. The E.P.S is one pound per cubic foot density (pcf).

The E.P.S. insulation will not rot, shrink, absorb moisture, compact, or deteriorate due to age or weather. It also acts as a vapor barrier for your home, providing stable performance year after year.  The E.P.S. is:

·         permanent

·         chemically and thermally stable

·         resistant to mildew

·         provides no nutritive value to animals, plants, microorganisms

·         non-irritating to skin

·         Chlorofluorocarbon (CFC) and formaldehyde free.