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Yumadome — A Multigenerational Monolithic Dome Home

Image: Eight suites — They are located off the atrium. French doors open to a balcony overlooking the atrium.

Eight suites — They are located off the atrium. French doors open to a balcony overlooking the atrium. (Mark Henrikson)

Image: Fish-eye photo — View using a “fish-eye” lens. It captures the domes depth and expansiveness.
Image: Christmas preparations — Atrium is decorated for the holidays.
Image: Atrium — It includes a central eating area and a place to relax. Large windows provide the home with lots of light and an open atmosphere.
Image: Let there be light! — Windows adorn every level of Yumadome.
Image: Up and Away — Staircase leads to the second and third floor suites. Most of the bedrooms are away from the atrium and the sitting rooms.
Image: View from the third floor — Stone tile flooring provides an earthy-feel and generates a striking contrast to the white staircase and wicker furniture.
Image: Deck the halls — View from the top using another “fish-eye” lens. Christmas lights and decorations adorn the staircase.
Image: What’s cooking? — Centrally located kitchen includes two dishwashers, two sinks and two refrigerators.
Image: Personal spaces — Each suite has at least one bedroom, a bathroom, sitting room, laundry area and closet.
Image: A living area — Residents furnish and decorate their suites.
Image: A sweet suite — It includes a sitting area, bedroom, dining area and french doors that lead to a balcony overlooking the atrium.
Image: Cozy bedroom — It’s decorated with floral prints.
Image: Victorian bedroom — It offers lots of light and a simple, clean design.
Image: No wasted space — This small bedroom features well placed, streamlined furniture.
Image: Suite comfort — Oversized corner bathtub in one of the eight suites. Arched opening is accented with beautiful floral arrangements.
Image: Generous storage — Wood cabinets provide storage in this bathroom.
Image: Bath time — This suite includes a Jacuzzi tub.
Image: Beat the heat — The folks at Yumadome enjoy their pool.
Image: Picnic time — Yumadomers have an outdoor picnic area and garden.
Image: Pool — The roundness of the pool complements the roundness of the dome.
Image: Welcome! — A curved path leads to this entryway.
Image: Spectacular Surroundings — Yumadome is enclosed by beautiful fields and mountains.
Image: Yuma Dome — It’s a beautiful dome in Yuma, Arizona with a diameter of 84’ and inside height, from floor to ceiling, of 39’8". It offers a total of 11,000 square feet of living space.

Happiness and family

Comedian George Burns once quipped, “Happiness is having a large, loving, caring, close-knit family in another city,” and his audience probably laughed and nodded in agreement. But there’s a unique family of eleven adults in Yuma, Arizona, who — while they might laugh — would not agree. This group — related to one another either biologically, through marriage, or simply through friendship and a shared sense of values — all live at Yumadome.

The ole’ homestead

Yumadome is a giant Monolithic Dome, built as a hemisphere, with three stories, an 84’ diameter, a 39’8" inside height from floor to ceiling, and 11,000 square feet of living space. Its dome shell encompasses eight suites, each with at least one bedroom, a bathroom, sitting room, laundry area and closets. In addition to the suites, on its lowest level, Yumadome has roomy, comfortable common areas: a kitchen with two dishwashers, two sinks and two refrigerators; a computer room; a TV room; and an atrium with trees and natural light. Fifty feet from the dome, a metal barn houses a workshop, garage and storage space.

One dome for four generations

In 1994, Mark Henrikson, one of Yumadome’s planners, spotted Monolithic’s ad in Popular Science and sent for a brochure — that he quickly read and put away. “But three years later,” Mark said, "Mary, my wife, and I were planning on building a house.

“Then,” Mark continued, “we learned that Dianne and Jim Grider, Mary’s parents, were also planning on building. They wanted Curly Pugh, Dianne’s dad, to move in with them, since he was in his 80s and sometimes needed extra time and attention.”

A little later, Mark learned that his sister Judy and Tim Williams, her husband, had just sold their house and were planning to build.

That core group was soon joined by Mark’s parents, Marcy and Jack Henrikson, and by the Williams’ two adult daughters, Rozz and Crystal.

At that point, Mark suggested to all the prospective, new-home builders that “maybe we ought to approach this a little differently.”

The group decided on a 13-acre parcel of land that they all liked. But they couldn’t decide on individual dwellings or on one all-accommodating home until Mark remembered Monolithic’s brochure. “Surprise, surprise — after three years, I found it!” he said. “That’s a sign right there that something must be going on. So we sent for more information and began looking at doing one, big house.”

Mark and Tim attend a Workshop while the group designs

In April 1998, Mark and Tim participated in one of Monolithic’s Workshops to study and experience the basics of Monolithic Dome construction. Meanwhile, the rest of the family got busy designing their ideal group home. Mark said, “We asked everybody to sit down with sketch or graph paper and draw the suite of their dreams. We told them to, ‘Just draw what you want.’ No limits at this point. And everybody pretty much started doing that. Eventually, we had to tell one of my nieces to think smaller and the other niece to think bigger, but after several months it all worked out.” With the help of a computer program, they came up with what Mark calls, “a relatively set floor plan, but we still had plenty of changes.”

Once the changes were dealt with, the Yumadomers hired contractor Chris Hengl to do most of the labor, with Mark and Tim doing the less technical tasks and everyone else helping with whatever they could. Nevertheless completion of the project took more than two years, since members of the two younger generations had to maintain their full-time jobs.

Yumadomers move in

Despite pride and happiness in what they had accomplished, sadness overshadowed the Yumadomers move-in. Jim Grider, Dianne’s husband, had died. Mark said, "Jim lived long enough to see us finish the shell. I really think he stuck around for that. He worked very hard. He had cancer, but managed to live for two years with cancer that most people don’t last six months with. I really think he was waiting to make sure we got far enough, so that he knew Dianne was going to be taken care of.

“In a way, Jim actually got to move in first,” Mark continued, “because his ashes are up on the hillside, above our dome.”

Everyday life at Yumadome

What’s it like to share a home with ten others — many of whom are not as old or as young as you are and most of whom have individual interests, likes and dislikes?

According to Mark, at Yumadome, it’s surprisingly pleasant and conflict free. He said, “If it’s during the week, those who work go to work pretty early, and those who are retired do whatever retired people do.”

Meals, cooking and cleaning

Depending on work schedules and other commitments, the Yumadomers eat most of their dinners together. Mark said, “On weekends, we usually have breakfast and a late lunch together, and, of course, we’re still working on the dome so we work together. There are plenty of things not quite finished.”

Dianne, a retired nurse who enjoys cooking, does most of it and the grocery shopping. When it comes to meal planning, she sometimes asks for the group’s input and preferences, and she sometimes simply fixes what she thinks they will like. Dianne also usually cleans the common rooms, while residents of each suite maintain their areas and laundry.


The Yumadomers established a “family account” to which each household equally contributes and from which bills are paid, including utilities and maintenance. To Mark’s relief, Dianne agreed to oversee that account. “I asked Dianne to take care of the money, collecting it from everybody — things like that,” Mark said. “She’s good at it, she’s willing to do it, and I appreciate it immensely because I’m not good at that kind of thing.”

Asked if there are many disagreements about arrangements or how things are done, Mark said, “No, not at all. We’re all kind of trying to share things — expenses, labor, whatever. We’re still working some things out. As time goes by we learn more — what the utilities add up to and so forth. But everything is shared as everybody can.”


Noise-control played a significant role in Yumadome’s design. Rooms were planned so that the head of a bed was never against a TV on the other side of a shared wall. Mark said, “Noise really isn’t a problem. Most of the bedrooms are away from the atrium and the sitting rooms in between, so if you have to sleep or have it quiet, you go into your bedroom and close both sets of doors and you have it quiet. There was one wall between Curly and Dianne’s that we were kind of concerned about, so we had soundproofing put in there.”

Indoor temperatures

Each of Yumadome’s three floors has central air, with a separate thermostat controlling its temperature, but all three are usually set about the same. Mark said that during the winter, the dome itself doesn’t need much, but some of the older residents like a bit more heat. They get that by using a small space heater in their suite.

Experiences in Dome Building— YUMADOME!

by Mark Henrikson


My name is Mark Henrikson and I’m the proud owner (well, part owner with many others of our family – four generations!) of a Monolithic Dome home — Yumadome.

We started our project about 6 years ago when several parts of the family were all looking at building houses at about the same time. Mary and I had read a little about domes that was positive so we decided to learn more. The more we learned, the more we liked what we saw. We live in potential earthquake country and occasionally get the tail end of a hurricane so the incredible strength of the domes was a plus. Living in the Arizona desert made the energy efficiency a bigger plus. Finally, the fact that it was possible to do much of the work ourselves to save money made the decision pretty easy. We were going to build a dome!

I won’t go into all the ‘learning opportunities’ we experienced while building our home, but suffice to say, with the whole family involved, we made it happen. We are still fine tuning and finishing things, but have been living in Yumadome now for two years.

The things that attracted us to the domes in the beginning have been pretty well realized as the following tales will tell.


Fortunately, we haven’t had any bad earthquakes yet but we did experience several small ones. The first was before the dome itself was up but had a sprayed shotcrete retaining wall just barely in place. We had just sprayed a coat of shotcrete that day and had a minor earthquake that night. All I could think of was coming the next day and finding a bunch of cracks in our brand new shotcrete… guess what… not a mark!

The second one was after a fair amount of framing was in place and we had already poured the concrete second floor (about 180,000 pounds of concrete!) I was working on putting in one of the exterior doors and felt things swaying… at first I thought I was just working too hard (nah… that can’t be it!) and then realized that it was an earthquake. The bubble in my level was sliding back and forth and my mother-in-law came in and said things were really rockin’ in the garage. With the steel framing I would have expected to hear some popping or groaning… not a sound!


In spite of several design decisions we made that cut the potential energy efficiency we are definitely saving money on our utilities. Our last home was about 3000 square feet and our electric bill (with gas appliances) averaged about $175-200/month with a high of about $250-300. That was with a load controller which helped save us money with the electric company. Yumadome is four times that size and our average bill is about $450 with a high of about $750-800. That doesn’t sound like all that great a savings — probably around 25% cheaper than you would expect if you compare square footage. The difference is that on Yumadome, we have a panel of windows (for the view of the valley) that is about 1000 square feet (60’w x 18’h). Ask any HVAC guy and he’ll tell you that windows are terrible for insulation. We also have 11 (yes, eleven!) refrigerators &/or freezers of various sizes in the dome. We also have an electric range instead of gas. Lastly, I suspect a fair amount of money goes into the fact that we have our own well. We use a lot of water on landscaping for various reasons and that well pump draws about 2.3KW/hr. It wouldn’t surprise me if it runs at least a couple hours every day.

With all those things that burn more power than what a typical house would use, we are still using at least 25% less power than what our last house did… and that’s before we get the outside decks up that will help keep the sun away from many of the doors.

Ease? Of building?

I guess “easy” isn’t really the right word. There’s nothing easy about building an 11,000 square feet house with a bunch of amateurs who almost all work full time. But, we managed it! My mother lives with us now but wasn’t here until after we were living in the dome. She was always asking me “how in the world did you learn to do all this?” I get asked that a lot. My answer is simply this: “Ask questions”

In very rough numbers, our initial budget showed us spending about $40-45/square feet for the house. That’s just a hair less than when we did our last house. This isn’t because the dome is cheaper to build, it’s because we did more of the work ourselves. Our last home we paid for someone to frame it. With the dome, we did all of the framing ourselves.

If you can take the time, you can save a lot of money on just that one step. The difference is that you won’t be as fast as the pros are, guaranteed! You will also be more careful than they are… after all, it’s your house.

Always assume that it will cost more than your budget said it would. I didn’t keep the records I should have but we probably ended up about 15-20% over what we expected. Some of this was because of things we didn’t think of. Some of it was because of upgrades we decided on the way. For instance, we never planned on having granite countertops, they cost a fortune! Partway into the project, we spotted an auction where they were selling granite slabs for about $30/linear foot. That’s a real steal! We went a little crazy and also bought slate tile for the entire public area of the dome… something like 3000 square feet. The price was so good we couldn’t pass it up, but it was an upgrade from our initial budget.

Could we have done the same with a stick-built house? Sure, but we wouldn’t have the benefits of the dome. We did hire some help when it came to spraying the shotcrete. We needed more ‘educated hands’ than we had for a project of this size. Something about spraying nearly a half million pounds of concrete in the air and wanting it to stay there, kind of screamed for a little extra help. Grin!

Find subcontractors that you trust to work with you. There are good and bad ones just like anything else. If you haven’t done any building before, you may want to subcontract more of the work. If you are real handy, you can do more yourself. Ask your friends about who they have used before.

You have to balance the time you can take to build it against the cost of having pros do the work. There are a few things that you just can’t do yourself cheap enough to bother with them. To me, these are carpet stretching (I just wasn’t willing to try it on this scale), roofing for big jobs (not much of this on a dome unless you have it joining to conventional portions, and fiberglass insulation (same as roofing). The last two especially, you usually can’t buy the materials cheaply enough to save much money.

All in all, I’ll close with pretty much the same thing I tell most people about domes:

“There are only two problems with domes… everything else is a plus over a regular house:

  1. They can be hard to finance depending where you live.
  2. They look a little different. If you can’t deal with the idea of a house that doesn’t look like all your neighbors, then either don’t build a dome… or let your neighbors learn about how terrific domes are!"

Note: This is a combination of two articles. The first was originally presented in February 2003 and the second in March 2004.