This Dome Performs Like a Star
- By Carol Lanham
- April 1st, 2007
North Central Texas College (NCTC) was playing host to a nearly full house at its new performing arts center last spring when a fierce storm rolled through Gainesville, the small Texas town where the campus is located.
The lights began flickering about halfway through the first act of the play, and hail and rain began pounding the building, known as the FSB Center. After a few minutes the electricity went out, forcing the actors on stage to perform under emergency lights.
As the weather worsened, school officials decided to call a halt to the theatrical performance and bring audience members up-to-date on the weather conditions outside. Administrators were able to calm the worried audience and performers with these reassuring words:You are in one of the safest buildings in Gainesville.
The Strength of the Dome
NCTC officials could make that bold claim because their performing arts center is housed in an unusual, steel-reinforced concrete building called a Monolithic Dome. These structures are known, among other things, for their ability to meet the Federal Emergency Management Agency’s criteria for near-absolute protection from hurricanes, tornadoes, and other severe weather.
Dozens of school districts across the nation have opted for Monolithic Dome school buildings since Emmett High School in Idaho became the first to build one in 1987, but the structures are still relatively unknown to college administrators.
NCTC is one of only three colleges in the country that has built such a facility. The other two are Park University in Parkville, MO, which has a domed sports center; and the School of Communication Arts in Raleigh, NC, which opened a futuristic domed campus in 2004.
The few trailblazing college and university administrators who have opted for this unusual construction method have found that the structures live up to their tough-as-nails reputation.
For example, when last year’s spring storm subsided in Gainesville, an emergency disaster team brought in to assess damage found areas of destruction throughout the town, but the Monolithic Dome building had not sustained any structural damage.
The Cost Factor
Another advantage of the buildings is their energy efficiency. Because of the polyurethane foam used to insulate the structure and the thermal qualities of concrete, utility bills can be as much as 50 percent less for a dome than a traditional building of the same size.
An additional selling point for NCTC was the building’s relatively low cost. Although construction costs for Monolithic Domes can vary widely depending on the interior finish-out, NCTC officials found that the price was less than half of conventional construction.
The cost of building the dome, compared to a traditional building, is phenomenal, said Dan Doss, facility manager and technical director at NCTC.A normal square building would have cost us in the range of $12 to $20 million. This building ran us right around $6 million.
Doss said the cost savings enable small colleges like NCTC to have a top-notch facility that they otherwise might not be able to afford.
The FSB Center also gets rave reviews from the head of NCTC’s drama department, Thom Talbott. He points out that the circular layout enables them to accommodate 360 audience members in only 11 rows, with seating arranged in a diagonal or raked pattern around the stage. In contrast, the community theater in town has the same number of rows and can only seat half the number of people.
Even though we can seat more people, we have more intimacy. You don’t feel like you’re far away even when you’re in the back row, he said, pointing out that back-row seats are only 50 ft. from the front of the stage. That makes for great theater because you have a response going on between the actor and the live audience.
Gabrielle Fletcher, chair of the college’s fine arts department, also speaks highly of the building’s round shape. When you have something linear that’s squared off, it’s less inviting and not very intriguing, she said. Curves are more aesthetically pleasing, more comfortable, and much more creative, so it fits in with what we’re doing here.
But the building’s unusual shape also can serve as a deterrent for some college administrators mulling construction options. When they were first talking about domes, everyone was afraid it would look like a giant igloo, said Talbott. But it has a nice sense to it.
The FSB Center’s dome is flanked by an 18-ft. stem wall that gives the building a more traditional look. Inside, the dome has a diameter of 130 ft. and measures 41 ft. from floor to ceiling. That includes a 360-seat theater with 13,417 sq. ft. of clear-span space, and a lobby, classrooms, small lecture hall, and other spaces that bring the center’s total size to just over 25,600 sq. ft.
Architect Rick Crandall of Crandall Design Group in Mesa, AZ, who designed the FSB Center, described the dome as a circle within a circle. The radial design places the theater stage in the center with the audience radiating around the stage on one side and all services pertaining to the stage radiating around the other. It’s a very efficient use of space, he said.
The theater is at the heart of the dome, and has state-of-the-art features not available at any other performing arts center in the county, according to NCTC officials. The large proscenium stage is equipped with a 36-ft. turntable and a functional fly loft with a counterweight fly rigging system for scenery and lighting.
With theater you want to keep it as fluid as possible. You want to go from scene to scene without a break in between, just like a movie, Talbott said. The fly system allows us to be more creative and bring some new nuances to the performances.
Acoustics, which can be a challenge in any domed facility, are also considered superior at the FSB Center. In a lot of facilities, the acoustics are set for a particular type of performance, said Fletcher. For us — instrumental, choral, theatrical, even lecture — all of them sound good. It’s more of a multipurpose facility.
Getting the acoustics just right in the dome was the job of Porter Falcon of Falcon Audio-Video in Owasso, OK, who has been in the sound business for more than 40 years.
Two phenomena exist in domes. One is the ‘whisper effect,’ where if you were to stand on one side of the dome, what you said could be heard at equal amplitude on the other side, he said. The second phenomenon is the focal effect. Think of it as a satellite dish that gathers very low amplitudes from space toward the center.
To offset these two phenomena, Falcon installed a ceiling as well as a lid in the dome. He used a specially designed spray-on material for the walls and placed 30 decorative acoustical panels around the perimeter. Comparing the panels to modified Helmholtz resonators, Falcon said their use dates back to the ancient Greeks and Romans.
Putting It All Together
The dome itself also has a long history dating back to antiquity. According to David B. South, who co-invented and patented the construction method for building Monolithic Domes in the mid-1970s and is now president of the Monolithic Dome Institute in Italy, TX (www.monolithic.com), domes were commonly used in cathedrals and national office buildings, but later fell out of mode because they become too expensive to build.
The air-formed construction technique that South patented made the buildings affordable once again. Because of the technique that my brothers and I developed, domes are now easy to build even though they are superior structures in many ways.
Construction begins with the placement of plumbing and special electrical conduits and the pouring of a circular foundation. When the dome features a stem wall, it goes up next. Special anchors are placed around the perimeter that hold in place the Airform, a tarp made of tough, single-ply roofing material that creates the shape of the dome when inflated with giant fans.
After inflation, construction moves to the interior. As fans keep the Airform inflated, the interior is sprayed with a polyurethane insulation material in several stages, finally totaling about three inches. A grid of steel rebar is then attached to the foam, making the inside of the dome look like a giant birdcage. Finally, the rebar grid is embedded in a 2- to 3-in. layer of the liquid concrete known as Shotcrete. The result is a strong and permanent structure.
For a college located in a city that is right in the middle of tornado alley, the permanence of the facility is most definitely an overriding benefit. But in between severe weather events, officials at NCTC mostly just enjoy using the new, full-service performing arts facility. For us, it’s just been a great thing, said Talbott. We’ve enjoyed it completely and we constantly keep looking for new ways to utilize it and ways to maximize what we have.
Carol Lanham is co-founder of Business Writers Group, which is based in Dallas. She previously worked as a reporter for several major news organizations, including the Associated Press, Reuters, and Newsweek. Freda Parker contributed to this article.