Earthen Sheltered Home vs BOL Bunker

[txfireguy2003]

My brother is currently in the process of putting an addition on his home. He is using styrofoam blocks that you stack like legos, then fill with concrete. Once it's finished, you have a 6" thick, steel reinforced concrete wall surrounding the house, with 2" of foam on both sides. There is a provision for the cieling/roof structure to be made the same way, but he chose not to take that route for whatever reason. The material cost is signnifigantly more than standard wood frame construction, BUT it is feasible, if you have a moderate knowledge of tools and construction, to do the whole thing yourself minus the pouring of concrete. There is a little savings there, from not having to hire a framing crew, but the real savings comes when you live in the home for several years. A family just up the road from him built their entire house with the same foam product, and they claim that, in Central Texas, middle of the summer, their electricity bill to cool the 3000 square foot house, is around $100 a month! This when I'm paying in the neighborhood of $400 a month for a 1500 sqft house of normal wood frame construction with brick facia. It's basically like living in a styrofoam cooler, once you get it cooled off, it stays cool for a long time, and once you get it heated up in the winter, it stays warm. HVAC barely has to run at all if you seal the doors and windows etc. When I get around to building my home, I will be using the same stuff, building a small basement/man cave/shelter/gun room/reloading room, and putting the house on top.

[Outlander Systems]

If it's in your budget, go for a monolithic dome.

http://www.monolithic.com/

I believe they were initially designed as economically viable/sustainable homes for refugees.



I've been dreaming/lusting after one for years. In a nutshell, the home is constructed via a concrete pad. After the pad is cured, reinforcing rebar is installed, and an "airform" is inflated, which is essentially nothing more than an inflatable template for the home's layout. After the airform is inflated a mixture of concrete and IIRC, nylon, called "shotcrete" is hosed out of a pressurised sprayer onto the form/rebar. Construction is rapid, the home is literally bulletproof, and can withstand ungodly psi/wind. If I'm not mistaken, little to no special requirements are needed to partially submerge the house, and backfill over it for a subterranean setup.

It's been awhile since I've actively investigated the technology, but I also believe the monolithic domes are self-regulating, in terms of temperature, much like an earthen shelter.

The only caveat is that banks are loathe to finance anything that makes sense, like a MD.

[lalakai]

buried or underground houses work very well, as long as you plan for them, and accept the initial up front higher costs. As someone already pointed out, structural requirements are more due to the added weight, so your footings are critical. Room design and layout need to be carefully considered, to maximize air movement throughout the house, which will go a long way towards reducing the "musty-ness" that commonly occurs. If you incorporate a buried heat pump/exchange, and solar abilitiy, you can come very close to going completely off the grid. "lighting" is an issue, but I was in a home where the contractor had done some amazing things with fiber optics.

If i had the land and the financial ability, I would definitely opt for a buried house.

good luck.

[HES]

Great minds think alike. Im in the architectural field and this has been something I have been looking into for some time now, mainly as a way to save a buck. The fact that you can have an eaisly defended site is a bonus. An earthen home makes a lot of sense from a environmental / expense point of view. Do it right and your utilities costs can be dramatically reduced. There are a few web sites that specialize in this (as torquemada055 pointed out), but you will have to search hard for an architect that specializes in this type of construction to ensure you don't wind up with a big oops.

One of the questions you need to address is where you live. Your location, its climate, and geography will determine in large part what type of structure you have. If you live in a majority of the US, you may choose to have the exposed side of the structure facing south to catch the warmth of the sun. However if you live in Florida, you may want to face the exposed surfaces to the east or north to minimize your solar absorption. For water you can grade and shape your earthen roof to collect rainwater for drinking and add a solar cistern to have hot water for showering.

Then you have to consider how many people you want such a structure to support. The larger the structure the less in cost savings operations wise you will realize. If its just you and your wife and you can deal with 1,200 to 1,800 SF you are probably in the sweet spot.

Then you need to think about the type of earthen home you want. There are all sorts of types. There are those that are built above grade which are then burled. They can be built along traditional lines or you can use a series of interconnecting domes (excellent example by TheLandlord) or you can build them out of interconnecting freight containers. Or you may want to build below grade. Or use straw, or adobe, etc... There are a lot of different construction methods and materials. Again cost, geography, geology, and climate will help dictate what you wind up with.

Or course as others have said, if you want a conventional home there are options out there. One is pre-stressed concrete. Basically the walls are poured and cured in a factory (and can have the openings for doors and windows pre formed) and then they are assembled on site. The walls are solid and should be able to withstand anything a major hurricane or tornado can throw at them debris wise (this does not include the roof). The total construction costs are about the same as a standard cinder block built home you might find in Florida. Another option are the Styrofoam blocks that you fill with concrete.

I'd love an earthen home. When I wanted one when we were younger my wife said no way. Back then we could have started out small and added on over time. But she said no. Now she wants to. Some times I want to bang my head against the wall till it bleeds. Now it looks like we'll have to wait till we are empty nesters in about 10 years

[larry0071]

We used Superior concrete walls: http://www.superiorwalls.com/
Also, the garage is two story (under the 2 story house) and we used 8" parking garage slabs for the floor of the 2nd level garages.

[Rooster15]

http://www.monolithic.com/

These are what I would go with.