The Monolithic Dome Institute (MDI) advances the construction of the Monolithic Dome — a super insulated, steel reinforced, thin-shell concrete structure. Built worldwide for residential, commercial, and industrial uses the Monolithic Dome is beautiful, energy efficient, green, and strong.

Cutaway diagram of finished Monolithic Dome
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David, Barry and Randy South switched on the inflator fans to construct the first Monolithic Dome in April 1976. It was for a potato storage in Shelley, Idaho — 105-feet diameter by 35-feet tall, which was pretty ambitious for their first dome. It changed their lives. They patented the process and started changing the world, one dome at a time.

Today, there are Monolithic Domes throughout the United States and the world — from the Arctic to the tropics — used for schools, storages, churches, homes, gymnasiums, safe rooms and much more. There are domes as small as 8-feet to over 340-feet diameter with engineering for even larger structures. … read more

Aerial view of South Sawmill Lodge in Island Park, Idaho.
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It’s time to say goodbye to the South Sawmill Lodge. Randy South’s family of South Industries started the 90-foot diameter dome in 2009 on the old family homestead in Island Park, Idaho. Over the next four years, the family squeezed in time to finish the dome which became a lodge and reunion center rented out to dozens of families over the years. The lodge sold this spring. … read more

Monolithic Dome Builders Workshop Alumni.

It’s back! After a year and a half hiatus, the Monolithic Dome Builders Workshop resumes again in September 2021. Coronavirus restrictions are lifting. Travel is returning. We can finally gather to teach, discuss, and build another Monolithic Dome. … read more

Sketch of concepts used in the vertical ellipsoid dome calculator

Inflatable shapes are the basic components of Monolithic Dome design. If it inflates, it can be constructed … probably. There are two primary shapes that dominate dome design — the sphere and half-ellipsoid. However, these are not the whole design palette. Sometimes we need to go beyond the basics. or in this case, beyond half of the ellipsoid. … read more

The Callisto.
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Monolithic Domes are amazing. The insulation, coupled with the concrete’s thermal mass, creates an atmosphere that is hard to describe. Simply put, it feels the same today as it does in the middle of summer. If you set the thermostat at 70 (21°C), it just stays there. During the two-degree, 24 hour period, my heater ran for a total of 9 hours. This is a small heater, with only 30,000 BTUs. Most homes the size of mine have 100,000 BTU heaters, but even my neighbors with electricity struggled to stay warm with heaters running nearly 24/7. … read more

Ellipsoid dome conceptual sketch

Circles and spheres are easy to measure. Calculating a spherical dome’s floor area, surface area, perimeter, and volume are straightforward mathematical formulas. When I wrote the new Spherical Dome Calculator, the challenge was the scaled drawing, not the computed values. Ellipsoids — on the other hand — are hard. … read more