What's the deal with concrete geodesic dome houses?

Factual Questions
1

A specific company, called “American Ingenuity”, manufactures geodesic dome kits.

The kits are reinforced concrete panels bonded to foam insulation, and the edges are cut at the appropriate angles so that they assemble into a dome. The construction crew twists the wires stick out of the panels together and pours a high grade concrete mix into the seams between the panels.

The claim is that the structure is basically immune to tornadoes, windstorms, earthquakes, and other inclement weather events because of the shape and the structural strength granted by all the panels bonded to all the other panels.

The second claim they make is that since the entire structure is covered with high R-factor insulation, the energy efficiency is extremely high. What makes this better is the sealing is nearly hermetic, since each section is glued together with concrete, so that the overall structure does well on blower door tests. The houses require artificial ventilation fans to be running to keep them habitable because the air exchange with the outside is so low.

The final major claim is that the maintenance costs are lower and longevity of the house is much longer. There’s no roof to rot, no wood for termites to eat, no loose insulation to settle, and so forth. All of the HVAC ducts are inside the structural envelope, so it does not matter for efficiency if they leak air.

Apparently, these fellas have been in business for years, but I have never seen one of their houses. I asked about them on Arizona Wind and Solar, and one poster pointed out that the curved interior walls and ceiling eat into the usable floorspace for the home, since interior furnishings and appliances are all rectangular.

Has anyone here seen one of these things or lived in them? What are the drawbacks? Why aren’t we all living in these kind of houses?

http://www.aidomes.com/

2

A new twist on a 70’s Fad. Geodesic was a trend then, along with Mother Earth magazine. Building homes from recycled materials like bottles and cans was popular too. It faded in popularity because they offered less useable living space. They even started and almost finished a Geodesic hotel in Alaska.

This company has added the new twist of concrete.

3

Your post actually gave me an idea for an objective way to evaluate one of these houses. Using a touch of math, I would compute the dimensions of the largest possible cube that will fit inside the dome. The first and second floor square footage of that cube would count as 100%, as that square footage is just as usable as in a conventional house.

Then, I’d take the square footage of the rest of the structure, and count it as only 50%. This adjusted number would be the “fully usable” space of the home. I’d then be able to do an apples:apples comparison of the construction costs/square foot and the HVAC costs/square foot versus a conventional house.

And, yeah, these things are not as efficient a use of land. You could fit a bigger conventional house with more space on the same land. However, out in the suburbs, land isn’t generally the limiting factor.

4

A concrete house of a more regular shape will also be able to withstand a tornado.

5

For a short time I lived in a wood frame geodesic in Vermont one winter. Conventional square rooms were framed out inside it for the bathroom and galley kitchen and two small bedrooms while the open dome area was open living space and a sleep loft space on the roof of the “inner building” irc. It was an awkward space and freezing cold.

This is cool:The Biogenic Ecodesic Living Lighthouse
http://earthstar.newlibertyvillage.com/thebell.htm
http://earthstar.newlibertyvillage.com/plans.htm
http://earthstar.newlibertyvillage.com/BELL.htm
http://earthstar.newlibertyvillage.com/plans.htm

6

As is so often the case in marketing, the claims they make are true, but may or may not be relevant. Resistance to earthquakes and tornadoes is only an issue if you live in an area prone to those disasters, and even in such areas you might well decide that they’re rare enough that you don’t care. They are very efficient, but you can also make a very efficient home using conventional techniques. The domes will probably still be even more efficient, but it’s not a big deal if that means that your heating bill is only $20 per month rather than $25. And they don’t say anything at all about the difficulty in using the interior space, which is the main drawback of the design.

7

BTW the interior rectilinear structure filled one side of the dome. Back then these double story living/dining areas were popular.

8

In Alaska I once visited a huge concrete geo dome house but it was built on a level area cut out of the wall of a valley and then buried so that just one windowed side emerged from the valley wall. The owner said the dome structure was used to support the weight of earth piled on it. The vaulting curved ceilings were sprayed with horrible “popcorn” texture with sparkles in it. That place was huge! It was like a perverted McMansion variant of the plains sod house in the Little House on the Prairie series. That sod house in the story was excavated into a rise of earth like the place in this image here but much tinier: http://rider27.smugmug.com/photos/187326391-M.jpg

9

Another building technique I’ve seen is foam brick. The bricks are made from two pieces of styrofoam with plastic cross-braces. stack them like lego, then drop reinforcing rebar in down between and across the rows, before pouring concrete into the hollow core. Basically, preformed insulation and concrete form in one. you can build about one storey at a time. wires sticking out the outside can be used to attach stucco screen, or ramset strapping wood for siding.

So there are a lot of foam/concrete options. Roger Dean’s art book Views describes another technique from 40 years ago - a large balloon is inflated, sprayed with urethane foam then with concrete to make realtively free-form bubble structures. The disadvantage of non-rectilinear structures is of course, all our building materials (gyproc, doors, windows, plumbing, furniture, appliances etc.) are designed for straight lines and boxes.

The foam brick one looks very much like a normal house (the roof is usually normal wood truss, plywood and shingle). A full dome has an advantage there. I have heard second hand that people find these houses very well insulated and amazingly quiet due to solid, insulated construction that blocks outside noise.

Of course, almost any modern well built house in Canada today has an emphasis on sealing the house to limit air leakage. Modern sealed windows and doors also help. Thus, most need an air-exchanger (recapture heat from exiting air) as part of the ventilation to permit good air circulation.

The major advantage of a panel geodesic dome is (I assume) that it can be assembled onsite from small pieces - less construction work, bracing, fancy scaffolding, etc. The obvious question is how the internal structure works - second floor, etc. how complex is it to build the floor up to the wall? At least the wall is straight lines so the carpentry work on floors etc is simpler (or do you pour them too?) And of course, you still have to pour concrete afterwards - but I assume for the Mother Earth News types, it can also be done in small batches with a shovel and a mixing trough, a few seams at a time, instead of needing a giant cement truck.

Finally, this sort of building is great for your rural or cottage country, but in a nice suburban street (a) you may get pushback from the city and (b) good luck selling anything seriously unusual should you decide to move.

10

Coincidentally, I just listened to a podcast about the history and design of the inflatable construction concrete domes. Here’s a link to the transcript, audio, and accompanying illustrations. 99% invisible – Bubble houses.

(IMO the podcast is often fascinating, though sometimes they lay on design and architecture wankery a bit to heavily for my taste).

11

Here’s a good read on the negatives of the design (not concrete, but many of the complaints carry over):

http://www.shelterpub.com/_shelter/domebuilders_blues.html

12

yep. this.

13

Insulated concrete forms

For example Arxx blocks

http://www.arxx.com/

14

Short answer: Because what works on paper doesn’t equal great living experience. I’m not being snarky, you could apply that same logic to every aspect of modern living.

15

I stayed at a hotel in Cozumel, Mexico where the ‘rooms’ were individual concrete domes. I wonder if they were made in that fashion. It seems possible, since the hotel was pretty old,AFAICT. :confused:

16

Ya think?

17

I would think the solution to the insulation problem was either to use 2 x 6’s or use spray on foam insulation.

18

Y’know, those hanging treehouses might not be very practical, but they’re definitely way cool.

19

Plus, concrete domes may look pretty (YMMV) but in a temperate climate with even small cracks and freeze-thaw cycles, some sort of waterproofing and other finishing is likely called for.

20

This reminds me of he UC Davis domes. They were originally built in 1972 as an experiment. There have been at least two calls to dismantle them, but they have, not only a community, but fans, too.