A Unique Addition

Is it a UFO?

The night after our home addition was inflated, some of the neighbors thought a UFO had landed. A soft orange glow radiated from the elliptical bubble. It almost seemed alive.

Sound like something from a science fiction movie? The foam and concrete dome has something to do with science, but there’s nothing fictional about it. When my husband, Chuck Cozzolino, and I decided to add some living space to our ranch-style house, we looked into several possibilities. A traditional box shaped addition would have been a good architectural choice, but would have been too expensive for the amount of space and energy efficiency we wanted.

Thinking domes

So we decided to look into the kind of home I’d been fascinated with since the 70s, when I first read about them in Mother Earth News. Geodesic domes, sold mostly in kit form, are formed by joining pyramid-shaped tetrahedrons together. These domes are usually framed in wood and the outside is covered by shingles or cedar shakes.

Most companies who sell kits offer a basic package containing directions and material to frame the dome. Some offer triangle and pentagon windows, roof shingles and interior drywall or wood paneling for an extra cost.

Domes save energy because there is less surface area per square foot to heat or cool compared to the square or rectangular home. It also allows wind to blow around it rather than into it. The curved surface also has drawbacks. It’s difficult to shingle and the triangle studs that form the inside walls make dry walling a nightmare. We planned on doing most of the work ourselves and the thought of these two jobs made us continue our dome search. We found a company in Florida that manufactured a concrete and foam geodesic kit. This was an appealing idea because the prefabricated triangles didn’t need to be shingled. The concrete panels needed only to be seamed with cement and painted.

The triangle panels could be ordered with precut drywall attached to the inside but would still need to be finished. We decided to visit a couple in Tennessee who had built one. The open floor plan made the inside of the 34 foot diameter dome look spacious. A loft covering half of the interior, overlooked the living and dining room. The house was radiant heated with hot water tubing in the floor. With Tennessee’s relatively mild winters and the exceptional efficiency of the home, the couple’s electric bill was minimal. Two ceiling fans kept the dome cool in summer.

Discovering Monolithic

We were about to order one of these kits when I saw something I’d never seen before in a dome magazine. Instead of being made out of triangles or tetrahedrons it was one flowing shape. It was called a Monolithic Dome. We immediately sent for more information.

We found out that these domes are built in a very unusual way. After a concrete ring foundation is poured, a heavy vinyl Airform is manufactured to the shape and size of home requested. The Airform is spread out and fastened to the foundation. Large blower fans inflate the Airform and remain on during the construction process. Everything else is done from inside. The doors and windows are framed in. Then several layers of polyurethane foam are sprayed on the interior surface of the Airform until there is approximately 3 inches. Steel reinforcing rebar is attached to the foam followed by three inches of Shotcrete, a special spray mix of concrete. The Shotcrete can be smoothed out or left as is for a textured effect and is usually spray painted white. Other than that, the interior wall is complete.

The vinyl Airform is the only covering needed on the outside and will last 10 to 15 years before it needs to be painted or stuccoed. Because the rigid foam insulation is on the outside (protected by the vinyl) and the concrete is on the inside, the dome acts as a heat sink, storing heat in the winter and keeping it out in the summer. This is the most energy efficient housing we read about aside from underground housing. It’s also one of the strongest.

Chuck and I loved everything about the Monolithic Dome except for one thing. Like the other domes, it was being sold to the do-it-yourselfer. There were two companies owned by brothers who had been building these domes since the 70s. Barry South’s company, Dome Technology in Idaho, continued in the business of building large domes for use as churches, schools and storage facilities. They had built a large temple in South Bend, Indiana, for Lester Summerall’s ministry.

David South owns Monolithic Constructors, Inc. in Texas. His company makes Airforms, trains people to build domes of all sizes, and spreads the word about Monolithic Domes via a quarterly news publication.

After many phone conversations I finally convinced David South to contract his brother to construct our dome.

Dome up!

After the crew attached the Airform to the foundation, it took less than half an hour to inflate. A light made the dome translucent for a couple of nights until the foam made the structure opaque. Lots of people stopped by to see what was going on. It took four builders exactly one week to raise the 36 foot diameter dome. The cost of the project was $34,000, which included site preparation, foundation and floor, plumbing and electricity, radiant floor heat, window and doors and the connection between the ranch and dome. We have run into some problems, but most of them have been solved. We lost a lot of heat through the windows the first winter, but we now cover then with foam panels at night and our total heating bill is only a few dollars more than before the addition. We also had problems with leaking windows that for the most part have been taken care of. Every year we do a little more to the interior. Chuck is just finishing a concrete block shower for what will eventually be the bathroom. A loft is also slated for the future. The floor plan will remain open, except for the bath and utility rooms. We’ve enjoyed our new addition for four years now, but one of the things we like the best is how music sounds in here. Rock, blues, jazz and classical – you’d think the performance was going on right in the room with you.

A dome, particularly a concrete dome, isn’t for everyone. But if you like open spaces, room flexibility, low utility bills, strength you can count on, great acoustics and a Jetsons meets the Flinstones look, try one. We think you’ll like it.

Note: Cristine Timmons is a writer for The Herald-Palladium newspaper in St. Joseph, Michigan. Reprinted with permission from The Herald-Palladium in the Fall 1997 Roundup.