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Once built, the thermal mass of the concrete shell evens out temperature fluctuations. The heating/cooling system circulates air against the wall to maximize thermal storage. Unlike conventional systems, a dome's HVAC design does not provide a constant flow of fresh air to replace conditioned air. Instead, a carbon-dioxide sensor determines when to allow fresh air into the dome.

Monolithic Dome Schools

Schools have been among the most popular uses for monolithic domes. School districts in Arizona, Missouri, Idaho, Oklahoma, Minnesota, Florida and Texas have built or are planning to build them.

Texhoma, a small community straddling the border between Texas and Oklahoma, is a typical example. The district had not passed a bond election in over 20 years. When superintendent Rick Kibbe reviewed his options, he found that either building a new facility or remodeling the 65-year-old existing structure would have cost more than the district could afford.

"Frustration was beginning to creep in," recalls Kibbe. Then he discovered that a monolithic dome would give them more building area than either of the other two options, and at a much lower cost. He was able to convince his school board, and the district now has two domes under construction.

The school district's savings don't end with the building process. By cutting in half the $7,000 per month they had paid for heating and cooling, they expect the building to pay for itself in just a few years.

Monolithic domes have another big advantage for small towns like Texhoma. Because they are fireproof, earthquake resistant, and can withstand direct hits from hurricanes or tornadoes, they also serve well as emergency shelters for the entire community in the event of natural disaster.

Monolithic Dome Churches

Because the dome form has been part of church architecture for centuries, it is only natural that churches are a popular application for monolithic domes.

Faith Chapel Christian Center in Birmingham, Alabama recently completed the largest monolithic dome church ever built. It has a diameter of 280 feet (85 meters) and will provide 62,000 square feet (5800 square meters) for a sanctuary with seating for 3,000.

Other large congregations that have chosen this construction method in the last year include St. Agnes Baptist Church in Houston and the Home of Life Church in Chicago.

Pastors cite the benefits of energy efficiency, safety, durability, and relatively low cost to construct. But they admit the round shape can pose some challenges for architects accustomed to working "inside the box."

"It's different," says Gustave Heye, who designed Church on the Rock in San Antonio, Texas. "We're still getting used to walls that slope slightly around the perimeter. We had to learn to work with a second floor that is not stacked exactly atop the first floor, so it's an adjustment in thinking."

Sports Facilities

While a church currently holds the record for the largest monolithic dome ever built in the United States, there are even bigger ones on the horizon.

David B. South, who co-invented and patented the process for building these domes, was recently awarded a patent for the "Crenosphere." This is a huge concrete structure capable of housing large-scale, indoor sports events. Their diameters range from 300 to 1,000 feet (90 to 300 meters) with heights up to 500 feet (150 meters).

South, who is now president of the Monolithic Dome Institute in Italy, Texas, says one of the Crenosphere's major advantages is its relatively low cost. "In some situations,", he says, "the cost of building a Crenosphere could be half the construction cost of other types of sports facilities with nothing sacrificed in playing space, spectator seating, or amenities.

The Crenosphere also offers significant interior design flexibility because it has a clear span with no support pillars or posts to obstruct views.

Bulk Storage

The first monolithic dome that South built — with his brothers Randy and Barry — was a potato storage facility in Idaho. Now, a quarter century later, domes continue to be popular for bulk storage of commodities such as cement, sand, fertilizer, feed, and grains.

Capacities of the domed storage facilities range from a few hundred to many thousands of tons. It is the hoops of rebar buried in the concrete — sometimes up to one million pounds (450,000 kilograms) — that enable the buildings to withstand the enormous pressure from the materials inside.

Monolithic Dome Houses

Hundreds of domed residences have been built around the world. They range from 300-square-foot (28-square-meter) rental units to million dollar luxury houses. There are even a few underground.

Homeowners' reasons for selecting this building technology are similar to those of commercial builders: energy-efficiency, safety, and durability.

A new type of structure, known as the Orion, combines the strength and integrity of a monolithic dome with the convenience and more conventional (round-in-plan but vertical) exterior walls. These walls are created with plywood panels topped with a 12-inch (30 centimeter) ledge on which the airform is secured for otherwise typical dome construction.

The first Orion has 2,400 square feet (223 square meters) of living area on two floors. Its creators envision entire subdivisions of such structures.

The EcoShell

This building technology may someday provide a solution to housing shortages in developing nations. The EcoShell is a concrete shell without insulation but durable and inexpensive to build. They may cost as little as $1,000.

Catalytic Software Inc. recently selected the EcoShell as the primary source of housing for a new company town in India. The 250-acre (one-square-kilometer) town, about 15 miles (25 kilometers) from Hyderabad, will feature more than 4,000 domed houses for employees. Plans also call for domed offices, shops, houses of worship, and entertainment facilities.

All over the world, monolithic domes and their offshoots are making a mark on the landscape. This "new paradigm in construction" might one day become a widely used method for construction.

Sean Lanham is based in Dallas, Texas and writes for the Monolithic Dome Institute. Freda Parker contributed to this article.

A kindergarten classroom in Pattonsburg, Missouri is also the town emergency shelter. The town of Pattonsburg was relocated after flooding in 1993. Photo: Monolithic Dome Institute Unlike conventional HVAC systems with a constant fresh air supply, the domes take in fresh air only when needed and circulate indoor air to optimize energy efficiency. Image: David A. Collins A 400-foot (122-meter) diameter Crenosphere football stadium. This patented construction method makes possible of domes as large as 1000 feet (300 meters) in diameter. Image: Rick Crandall Monolithic domes work well for large-scale storage facilities because they can withstand large horizontal loads from the inside and support heavy equipment on top. Image: David A. Collins Architect Rick Crandall, has offered to design for free an entire domed subdivision for any established developer willing to build it. Image: Rick Crandall The Orion is a single-family house built with the monolithic dome technology. Photo: Monolithic Dome Institute The Orion is characterized by walls that are vertical but round in plan. Photo: Monolithic Dome Institute Curved ceilings in a cozy dome house. Photo: Monolithic Dome Institute   Click on thumbnail images to view full-size pictures.