I came across this interesting post today. A company called Green Magic Homes can build you prefab Hobbit House. Okay, the Hobbit thing is marketing, I’ll pretty sure they aren’t selling mostly to Hobbits.
Instead, let’s think more in engineering and design terms. Maybe there is something here for folks who want to live off-grid, or mostly off-grid. This basic design could also work for seasonal cabins, vacation homes, survivalists might also find it attractive.
The basic design is based on arches and domed spaces made from fiber reinforced polymers, or fiberglass. This is a material that offers exceptional strength for its weight.
A little engineering diversion here. High quality fiberglass is stronger than carbon fiber, and much cheaper. Carbon fiber has the advantage of being exceptionally stiff for its weight. That weight saving is why carbon fiber is so popular in aerospace applications. Weight is not that critical in building a house.
Many people confuse strength and stiffness, but they completely different properties. If you are going to have several tons of earth over your head, fiberglass is what you want. Ribs can be built into the structure to increase the stiffness.
The idea of building a structure based on arches also makes sense. The arch is a marvelous way to transfer load. The architectural arch has been around for a long time. There are many examples of arches supporting huge loads for hundreds of years.
I can imagine something like this built into the side of a hill, the kind of lot that’s normally very difficult to build anything on. So long as some common sense is used in selecting a site there would be a lot of advantages.
I would get a geologist familiar with the local conditions to thoroughly check out any potential site. You don’t want the side of the hill sliding down into the valley the first time there is a heavy rain. And so long as the structure is 50′ or so above the nearest running water, there is built in flood insurance.
And remember that fiberglass is the material of choice for boats, so if the earth around your house gets damp, it shouldn’t be a problem.
The earth provides greater insulation, so your heating and cooling costs should be minimal. This kind of structure should also be immune to high winds and even rain bombs. A case could be made for some kind of storm shutters to protect the windows from flying debris
If your site is remote enough that getting container trucks with the modules over existing roads is a problem, then DIY is a possibility. Fiberglass is a great DIY material. The Green Magic modules look solid, and they seem to have the necessary experience to make a solid product. Even so, if you want to be a modern day Jeremiah Johnson, fiberglass is a good way to go. I certainly would not advise building a house as a first fiberglass project, but a summer spent building some other projects could get you up to speed. If you think you could build a cabin on the same lot, you probably could build something like this on site.
A Hobbit House is definitely for the unconventional. But all in all, a prefab Hobbit House would be a pretty cool way to build a magical mountain cabin.
The links below have images of Hobbit Homes being built. Costs run about $42 sq ft for the modules. That doesn’t include costs for the foundation or the electrical / mechanical services. If built correctly, a house like this should last a very long time with minimal maintenance.