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[J13]

hello all, somewhat new here
something that i've noticed is that when there have been discussions about building a home there has been a move to have a secure room or some analog of it within the plans - what if the entire home was the secure environment? im not trying to build a multi-gazillion dollar place, but a modest two bedroom home with an average-for-the-area toolshed/workshop/garage that's about 40 feet by 40 feet by at least 13 and one half feet high attached to the house via a ramp or hallway - the best thing i can think of is a pair of linked earth-covered domes of approximately the same size with either wind or steam power generation - maybe both...there would also be a porch on either side of the house (front and back) the windows and doors would have working and rather thick shutters, was thinking that i would want at least 10 feet of fill over the roof and at least that much over the garage (except for the entrance doorway - kinda difficult to drive thru dirt)

what should this type of house be built out of? concrete is what im thinking of, but i may not have knowledge of something better/cheaper/easier,
do ya'll think the thin-shell domes are all that the various vendors' sites claim they are?
this would be kin to an earthship, but with a focus on security and low or no maintainance
any suggestions?
thanks
j

[Ian]

Well, if the goal is a secure home, I would start by throwing out all plans that call for significant amounts of flammable materials. No log cabins, no straw bales, and no stick-frame houses. That would leave you with rock, concrete (and its many cousins; papercrete, insulated forms, etc), earth (rammed, adobe, etc).

I don't have any experience with modern dome buildings.

I do really like the idea of an earth bermed and/or roofed building, though. It makes for good insulation and low maintenance, and it can help a building really blend into its surroundings. Ten feet of earth on a roof is probably way too much, though. The stuff is heavier than you might expect, and supporting 10 feet of it would require a huge amount of structure, with lots of loadbearing walls and/or pillars. the sources I've seen don't generally recommend any more than three feet on the roof (with the minimum for getting some effective insulation benefit being about one foot).

Another thing to consider for earth bermed buildings is that the earth will press horizontally against all the buried walls, in addition to the roof pressing down on them. So your walls need to have a significant amount of strength in that direction (and the forces get much higher when there's any groundwater involved). So, concrete tends to be the material of choice.

Is there a reason you suggest wind and steam power, but not solar?

[J13]

hello Ian, thanks for replying

im with you in removing any flamable materials

i've never heard of papercrete - you just gave me something to google, thanks

im shying away from the icfs because of the flamability issue and b/c im after a large amount of thermal mass within the conditioned envelope of the home and garage - to the point of thinking wild and extreme (expensive) methods of getting there - think of a multi-layer wall system with feet of gravel or a sand and gravel mix between layers.....

do you have any idea of how well rammed earth or adobe would hold up in the northeast? i think i saw on tv once that they put some sort of plasticized coating over the rammed earth to make it weatherproof - am i correct in thinking that this is common practice? or am i daydreaming and it was a heavy paint suited to the desert environ the house was in...

i was thinking wind and steam because both can be readily hidden in farm country - the windmil can retract into a silo - usualy there's a good bit of room up there even with the unloader all the way up and the hexapod sitting there supporting it...
the steam exhaust should be able to be hidden just like a regular woodstove exhaust, just with a little more volume, and the waste heat can be used to heat the home, heat the water and in the winter maybe clear the driveway, but i need to look into the requirements for the boiler, ect
was also thinking that steam would be a little more viable because in my part of the world, there are plenty of trees and a wood-fired boiler would be a great backup, as well as a diverse and useful tool

solar would work fairly well in the summer, but not so well the rest of the year.....

i know there's a contradiction - hiding a windmil in a silo, but for the site ive got in mind a silo would not stand out at all, in fact it would be missed if one of them were gone...

thanks
J

[Aviator]

I wouldn't rule out ICF construction.  The foam used does NOT support combustion, and if it's sheathed in a non-flammable material, it is no problem.  I'm planning to build ICF homes in Kentucky and I've been learning quite a bit about them.  I think my second choice would be steel.  ICF walls can perform to R-50 and have enormous thermal mass.  If you do the re bar correctly, they are nearly indestructible.  I checked out a development in Tehachapi where they were doing moderately priced 1800 sq ft homes and they said they were price competitive with wood.

[Ian]

Well, I'm certainly no expert on adobe construction. But from what I recall, it can work fine in wet climates as long as it's not in ground contact (doing something like topping the foundation with a 1 foot tall stem wall of rock or concrete would probably work very well) and not being hit by rain all the time (make some fairly long overhands on the eaves).

Here's a site you might find useful: http://www.greenhomebuilding.com/index.htm

Lot's of info on a bunch of alternative building methods/materials there (don't miss the links in the right column of each material's page).

For general underground housing info, I'd check your local library. There are a surprising number of books out there that can give you a good starting point on all the various engineering and aesthetic issues.

[J13]

thanks for the replys
i'll check out that sight Ian, as well as seeing what i can dig up about adobe, there may be some applications for it inside the house - maybe use it as interior walls, but i dont think it would last too long in the northeast

in your studies Aviator, have you seen ICFs used in a bermed/semi-buried house? are you planning to use the ones that have the wall as a solid concrete wall or more as a thick-lined grid? if you have links to a specific one that you think is best, i'de love to take another look at 'em - so as long as i covered the foam with some sort of plaster it would be fine - ive got to re-evaluate

thanks again
J

[JOROWA]

Check out monolithic domes at www.monolithic.com .  They are extremely strong buildings providing most of the advantages of underground, without a lot of the underground problems, such as water leakage, condensation, and expensive heavy load bearing walls.  The deeper you go, the more it costs.  That said, you can bury monolithic domes.  Costs are competitive with stick built homes, provided you don't get carried away with the design.  Concrete and steel requirements go up if you want to bury them, but only about 10-15 percent.  They have large thermal mass as an inherent property of the structure.  ICF's generally only use half of the concrete as internal thermal mass, as half of the concrete is on the outside of the foam insulation.  Monolithics use all of the concrete as thermal mass as it is all inside the foam insulation.

[Aviator]

J13,

The system I plan to use is Nudura, www.nudura.com .  I had a chance to see houses built with this system in Tehachapi a few weeks ago, I was very impressed.  There are steel clips available that are cast in place and make it easy to install floor joists and roof trusses.  I'm investigating steel for these applications.  My cousin in Canada is an architect and she says they commonly use ICF for basements and foundation structure, but they don't use it for the upper structure commonly because wood is still cheap there.  Check out www.architecturaldesigns.com , they have a group of ICF designs.  This is one I like very much: http://www.architecturaldesigns.com/house-plan-35052gh.asp .  It should be very energy efficient.

[Rarick]

Do a search, there are at least 3 threads where we have talked about this.  My vote goes to the monolithic domes if you are burying the house.  The domes require the least reeingineering a modification, and all ready have a decent amount of protection on exposed walls. There are free standing monolithics domes (see the website) that have taken direct hits from tornadoes, fire, and hurricanes with minimal-no damage.

use the search feature, there are a couple of threads groaning with links and info.

[J13]

 
you're right Rarick - shoulda done a search - there's WAY more than 3 threads on this topic

ive looked at monolithic domes, they looked good, but not as geared to the DIY'er as www.formworks.com i spent almost an hour on the phone with him yesterday and have decided to go with them - the houses they have built are able to withstand almost anything

he told me that a dome they built withstood a simulated 50kt detonation at a 1500 foot stand off distance

the shell is 4.5 inches thick....

[Misfit]

Mr. Misfit and I are in the engineering phase of such a type of building/home.
He works for an engineering firm and will be doing the calculations on loads and such.
We're planning to do concrete block retaining walls as the exterior walls and berming in the structure on all sides except the south, for passive solar heating.
We're doing a concrete slab and are thinking of doing dry stack block walls with surface bonding and rebar in the walls. This may wind up being a traditional block wall if the engineer decides that would be better.

I looked into adobe and other similar materials and there seems to be an issue with strength uniformity. They're not consistent and so you may have an issue with stability. If you're in the northeast it would be really easy to build in the manner of the way they build basements there. You're just building a basement with no house on top. You'll need to paint the outside with a water resistant coating and have some french drains. Basements are not all that common in other parts of the country and would probably be harder to build elsewhere. I used to live in the northeast and we were surprised when we got to the southwest that they just don't usually do them out here.

[Rarick]

Southwest does not have the freeze/ thaw cycle that requires the deep footings.  Probably another reason for the southwest housing boom.  In someplaces about 2 feet down is a layer of Caliche- the stuff has to be jack hammered or blasted, and it is "resonant" so the vibration carries.  There are houses with basements, but you add anither 30+k to the price last I looked. If you are already in a development, foget about the jack basement and drop routine.  Almost all of the newer places have the C,C&R gestapo stuff. 

  Then again everyone on here is looking for low population..........

Bermed concrete block is a good one, especially if you are going DIY.  It will get you in shape too, if you aren't already.

[J13]

 
i feel slightly retarded - www.formworks.com should be www.formworksbuilding.com ......

the only problems that i can forsee if i'm doing all of the work myself is that im really good overbuilding stuff out of metal (made a flask out of 6061 T6 aluminium in high school - no section was under 1/4" thick, with the top and bottom at least 3/8" thick - could've used it to chock the tractor trailer i now drive with it without damaging the flask) but not so hot when it comes to building out of anything else

im a LOT more comfortable with letting someone else who has a clue design and plan things to my spec, especialy for the $$$ and safety factors involved

im thinking that adobe or its analogs may be good to construct some of the outbuildings im going to need when i change my lifestyle, just so long as those materials don't require an excess of maintainance or stand out excessively.....



what im attempting to do is build a somewhat stealth retreat that i can live in full time

[JOROWA]

Misfit,

You didn't mention where you will be putting your insulation, but let me suggest that you look into putting extruded polystyrene foam panels on the outside of your concrete walls, and under your floor slab.  This will put all of the concrete thermal mass inside your home, which will help with your HVAC and passive solar design.  Also consider hydronic radiant floor heat in your slab.  Very efficient heating, cost effective, and helps distribute the solar energy falling on your floor.  The required water temperatures for radiant floor heat can easily be supplied with solar hot water panels. 

On the topic of footers, frost protected shallow foundations are covered by code, and are much cheaper and more effective than conventional deep footers.  You can Google frost protected shallow foundations and get a weath of info.  My builder has used them in Alaska.

As to DIY monolithic domes, How To Workshops are held multiple times a year at the Monolithic Dome Institute in Italy Texas.  Some students have went on to build their own monolithic dome home.  One such student is being highlighted today on MDI's home page at www.monlithic.com .

[JOROWA]

Sorry, that should be www.monolithic.com .  By the way, the workshops are hands on, and you actually build a monolithic dome.  The cost is $995 for a 5 day program.