Ok, need to exercize some of those gray cells between the ears. I am curious as to what are some of the construction techniques employed for building a living space that is completely under earth. I’ve seen shows about weird/strange homes, but they’ve focused on caves and walk-out earthen home designs.
I am curious if anyone cares to talk about homes completely under the ground, as opposed to being walk-out types. Being that I was born and raised in New England, where a basement is surrounded on all four sides with earth, I wonder if anyone has come up with designes for homes completely underground.
And while we like to be able to look through windows at the outside, how much time do many people actually do this, as opposed to getting sunlight, the weather, etc.? With this in mind and with increasing more sophisticated technologies, both in construction and in amenities, I wonder how ‘comfortable’ some could get before being carted off to the funny farm for isolation-induced mental breakdowns.
I ask all of this not because I have a real interest, but more along the lines of reflecting on science fiction literature from my youth and the concepts Isaac Asimov brought to my mind in Caves of Steel. Looking at the idea, one could save on siding, windows, etc., but the savings could wind up consumed in reinforced structure (to support the earth above) and other unknowns (to me).
Replies
You are talking about an earth bermed home and the concept was very popular in the seventies with the hippie self sufficiency movement and the gas price crunch.
Look up Mother Earth News for the fledgling concepts and go to your local library and I guess google for more up to date info.
When I lived in Michigan in the eighties we had a neighbor who lived in one of those. He was kinda weird...and real pale.
Converted missle silo's.
http://www.silohome.com/
http://www.missilebases.com/new/
http://www.roadsideamerica.com/attract/TXOPLmissile.html
http://www.missilebases.com/
Converted missle silo's.
Lemme guess ... missles not included. I'd love to work one into the mortgage, but what would we call it to confuse the loan office? Garbage disposal? lol
Actually, I wasn't thinking of converted spaces, but from-scratch.
missles not included. I'd love to work one into the mortgage, but what would we call it to confuse the loan office?
The bird is not the trouble, it's just some sheetmetal and plumbing and a some electronics. No, the trouble is in the logisitics, that cryoplant to keep liquid fuels is a bear to maintain (which is why you can pick up Atlas & Titan silos now).
And, per an owner of a former Atlas facility "somewhere in Arkansas" keeping the pumps running is a bit of an effort. Not that it floods or anything, so much as not having standing water going stagnant for less-than ideal air quality . . . Occupational hazard of my occupation not being around (sorry Bubba)
I believe one of our fellow BTers does something along those lines VA Tom maybe, he has the sig PAHS Designer Builder Bury It!
An architect that did alot of that stuff is Emilio Ambasz, just do a search under his name and I'm sure you will find info.
Somebody call my name?
I don't think what I do quite applies to Nuke's question. We have well over 400 sq ft of glazing. Inside here you don't notice that there's a couple hundred tons of dirt on the roof. Only the rear wall is windowless. Look up in your house and you see? Right, the ceiling. Same here. Well, your ceiling probably isn't quite the same as ours, but you get the idea.
There's a Yahoo group about making hobbit homes. Not anything I've paid attention to, but there's distinct interest.
PAHS stand for Passive Annual Heat Storage, our passive heating/cooling system. The originator of the concept certainly didn't envision our place. And we'd get better thermal performance if we had considerably less glass, or at least used window coverings. We don't think it worth the effort. Pretty comfy anyhow. "Requiring" neither heat nor ac. Dump heat all summer, saved for winter use. All without any active system, nothing to maintain or break.
A decade living here and we have another, larger, one started with very few changes. Here's our living space. More at http://paccs.fugadeideas.org/tom/index.shtml
Forgot to mention that these are cheap to build. The (similar) client house appraised 50% more than it cost to build. Several reasons for that, but the shell was a large part.
PAHS Designer/Builder- Bury it!
Edited 1/4/2006 1:35 pm ET by VaTom
Tom, I would suspect that "foundation" waterproofing is a big deal for your type of house. Is that right?
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I would suspect that "foundation" waterproofing is a big deal for your type of house.
You would think, but no. With the proper insulation "umbrella" 6 mil poly is all we use, above and below the insulation layers. Redundancy works great. And we get only 1 seam/layer. Remember that the dirt is not insulation, but heat storage, which requires insulation (and water shedding).
My client insisted on a traditional foundation drain. Never saw a drop exit. The umbrella extends, ideally, 20' from the perimeter. The heating/cooling system won't work properly if water is moving through the ground (taking heat with it). We pay attention to channelling surface water around the house. Dry dirt on the outside of the foundation works extremely well. And so far, always a hill above the house.
No problems, so we must be doing OK.PAHS Designer/Builder- Bury it!
I have no information to offer but I do have an intrest in this matter. after all the hurricanes, I,m ready to go underground.. 2+3=7
RE living underground, rodents do it, so why not people? BTW - I heard that CloudHidden, VA Tom and JunkHound were starting an alternative building forum - now Nuke wants to join too... should be some good info over there... Now all they need is a straw bailer.. :-)
Now all they need is a straw bailer.. :-)
I know a few of them (balers). They don't appreciate it when I suggest walls are the easy part. Just pile up pretty much anything. It's the roof that gets interesting, especially with much of a span.
Mostly bales are used as insulation, non-structural. Hard to handle (expensive) insulation. Heresy to suggest that on the alternative arch lists.
Cloud and I've discussed burying one of his domes. He says his engineer would have no problem with the earth loads. I'm enamored with thin shell concrete, but not balloon (air) forming.
How's this for a wall idea? Guy in Colorado is promoting the concept. Unfortunately nobody with the machine around here. PAHS Designer/Builder- Bury it!
Burying a dome - that's a novel idea...
As far as that pic, Humm... There definitely needs to be some more uses for the millions of tires in tire dumps. It would be hard for me to picture how a weather proof structure would be built out of those... Much stranger things have happened though. I'd be interested in seeing how it's done. BTW - the pic looks a lot like the blast mats that are used when rock is blasted during site development.
Monolithic (Cloud's type) also has domes designed for underwater.
Tire bales are promoted by Mikey http://touchtheearthranch.com/tirebales.htm
One of his clients http://www.tirebalehouse.com/
Pretty sure I prefer concrete for my house, but bales sure are interesting. Fast and cheap retaining walls?
I've got some large tires here that I declined to pay $60 ea for disposal, ~300 lbs/tire. My interest is grinding them. Know anything about that? Makes great playground flooring. Non-steel belted of course.
PAHS Designer/Builder- Bury it!
Back in the 80's-early 90's, U. Of Minnesota did a lot of research on underground housing. Just do a search for "Underground Space Center" and a lot of sites come up.
Far as I know that's what jump-started it all. The book is "earth sheltered housing design", 1978, ISBN 0-442-28821-2. They suggested further research. John Hait did that and come up with PAHS, published 1983. The Underground Space Center's big question, that Hait answered, was where to put the insulation. Takes a truckload.
There's a guy in E. Washington who claims he was doing even better, long before Hait, in the 60's. Incredibly obnoxious, but has come up with interesting heating systems, generally utilizing a metal roof to collect much higher temp air than I see, stored behind/under the house, generally strawbale. He doesn't want to use any concrete or steel, too much embodied energy, so can't very well do the spans I like with my earth loading. Galls him that I prefer a totally passive, and cheaper, approach.
Last house had 40' spans, 300 ton roof, and was incredibly inexpensive. As the crane guy pointed out, couldn't have done a conventional truss roof any cheaper. Shocked him. PAHS Designer/Builder- Bury it!
<<He doesn't want to use any concrete or steel, too much embodied energy,>>Does he amortize the embodied energy against the value of the increase in useful life of the structure, the differential in lifetime energy savings, and the total cost of disposal at the end of the structure's useful life?My guess is that your plan would come up the winner.
No, anybody who doesn't agree with him is obviously an idiot. He designs for owner-builders. Doesn't deal with appraisals/mortgages either.
My guess is that your plan would come up the winner.
That's my premise. And why I continue with what I'm doing. Always room for improvement though. That, and curiousity, are what keep me tuned in to his efforts. Actually, we had a private correspondence a few yrs ago when I was having problems with summer overheating. Turned out that when I climate-corrected for Virginia, our house outperformed what he was bragging about. Apparently he's doing better now, but likes to talk about what he "tries for", not what he actually gets. My problem was solved when I got a handle on dehumidification, mostly in the form of a heat pump water heater.
If you use degree-days, with it's 65º goal, we need zero supplemental heat.
PAHS Designer/Builder- Bury it!
>Burying a dome - that's a novel idea...I'm getting to this party a bit late, but I'll try to blend in.Burying an ITSA structure (insulated thinshell sculpted architecture) [edit: that's a new acronym we're trying out] is easy. The engineering needs little modification. But the irony is that there is little advantage to it. These structures are disaster resistant sufficiently all on their own that the burying isn't needed for that reason. And their energy usage is so slight that any decrease in usage for hvac would not pay for the cost of the additional excavation. So yes, it can easily be done, and yes, it has been done to great effect, but there's usually no need to do so. That said, I like berming where the lay of the land makes it appropriate, and would bury one without hesitation of the client desired.I like the PAHS concept, too.Would an ITSA structure work under water? It's been speculated upon, but not done that I know. People have also speculated on space colonies, too. New genres sometimes attract that kind of crowd. I prefer staying a bit more grounded and designing for the world I live in now and tomorrow.Also mentioned was an earth-formed dome. That was a precursor to the air formed domes. Pile and shape dirt, rebar and concrete, excavate dirt. That could not compete today on cost or performance with air formed (inflated forms) structures.>VaTom, CH, and Junkhound collaborating on alternativeSuch a beast is more realistic than this jokingly suggested! What's happening is a group is planning the third annual ITSA Convention for the summer. It was in Oregon the first two years and will be near LA this year. And a frappr map was just started to try and identify all the ITSA-type houses in the world. Thanks to the thread here by ncbuilder for introducing us to frappr...software is making things possible that were not possible just a short time ago.
Would an ITSA structure work under water? It's been speculated upon, but not done that I know.
My "reflex" is that the shape would be fine, if inverted (follows the pressure curve, for one).
Might make for an interesting forming challenge, though <g>.
U/W structures have some interesting dynamics, not just the obvious ones, either--the mechanicals can be right stimulating to engineer.Occupational hazard of my occupation not being around (sorry Bubba)
Those I've heard talking U/W stuff are never those with the money...just usually youngsters with an amateur sci-fi mentality passing the time and not intending to actually build anything. And those with the funding will be busy retaining engineers and not talking about it in bars and chat rooms. When people I don't know start jabbering about that and wanna be taken seriously, I usually take the Jerry Maguire approach: "Show me the money". I'm surprised I don't hear from them again. <G>
have never actually had haggis, but i stand by my original statement nonetheless
LoL!
My same reaction when folk want me to design their bar or restaurant, or heaven help me, yet another half-baked idea for a beer garden. I ask if they've ever worked in a bar, restaurant (or beer garden); the miniscule number that say "yes" are asked to explain their business plan that will be competitive in the local market. That's usually weeds the rest out <g>.
You want to open a beer garden, huh? Have you ever looked at the local climate? There's about 6 weeks of the year in the comfort zone, with maybe three additional weeks of partial days; how do you plan to make any money outdoors the other 40 weeks of the year? Have you checked to see how expensive a liquor license is? Do you know where to order product, and how much that will cost? Do you know anything about business overhead; or labor law, or . . . ?
They never have the money to show <sigh> . . . Occupational hazard of my occupation not being around (sorry Bubba)
Maybe I could make my beer garden in here. :)
View Image
Paint clouds on the ceiling. Play with the lighting to make it seem like its the sun moving across. Keep it a comfortable 68-70 year round.
But I agree and tend to laugh when I hear a bar advertising their beer garden. Yeah, ok, and its 98 outside with a 98% humidity.
Although since the topic is underground... When that lotto ticket hits, I'm gonna make my big shop earth sheltered. Poured concrete walls. Haven't decided if I'd go with a dirt roof or metal. VaTom's ceiling looks kinda neat. Maybe raise it a bit.
Would be awesome to have all the workspace without the ugly utility bill.
jt8
"The test is to recognize the mistake, admit it and correct it. To have tried to do something and failed is vastly better than to have tried to do nothing and succeeded."-- Dr. Dale Turner
Edited 1/5/2006 4:51 pm by JohnT8
Yeah, ok, and its 98 outside with a 98% humidity.
Which is good 'weather' for cold beer; but a harder business case to make in the same street as a bunch of air-conditioned bars . . .
That fuzzy green floor looks like it would be hard to get the tablesaw very level upon, though <G> Well, level twice, being the "tricky bit" . . .
But, there's room enough for a panel saw or two <woohoo!>Occupational hazard of my occupation not being around (sorry Bubba)
Those I've heard talking U/W stuff
Hmm, some of the same problems with being underground, now that I think of it. The transition from one to the other presents the biggest "weak spot" in the design.
Hmm, just had a mental image of one dome "up" and another one "down" on some sort of flexible mooring . . .
Oh, and for the record, I haven't got any money, either <g> . . . Occupational hazard of my occupation not being around (sorry Bubba)
I seem to remember a book I'd read (author, Chiras?) where he'd done his earth sheltered portion with earth filled tires.
jt8
"The test is to recognize the mistake, admit it and correct it. To have tried to do something and failed is vastly better than to have tried to do nothing and succeeded."-- Dr. Dale Turner
tom,
do you have any experience with pounding 300lbs of dirt into tires and stack'n em like blocks? a relative of mine in the syracuse, ny area has built part of his house this way, a little straw bail, a little cob. his brother just moved into his house built from straw bail and cob here in york, pa.
these alternative techniques are very interesting.
do you have any experience with pounding 300lbs of dirt into tires and stack'n em like blocks ?
Incredibly labor intensive, no. There are 2 tire houses here, both contractor built, both financial catastrophes.
Have you ever met anybody who built their own tire house, even if not an earthship, who'd do it again? I haven't. That's a major reason why those tire bales are catching on in Colorado. Mikey went beyond normal pounding of tires to another method of filling and now pushes the bales.
Most of the alternative techniques and materials are in the domain of owner/builders who discount their own labor. Take those same techniques and apply conventional cost accounting and they become quite expensive. Generally prohibitive to my mind. Rammed earth is an exception if it's mechanized. Fine Homebuilding did an article about it many yrs ago.
Before anybody jumps, I know there are contractors in the west who are building strawbale, cordwood, and cob houses for clients. I've also looked at the typical costs when available. PAHS Designer/Builder- Bury it!
I agree, right down the line.For those who could still afford the work, I've repaired earthships. I cannot understand how anyone could be BS'ed into that plan.It just doesn't work.And even if you can get your friends to come beat dirt into tires for a few days, you run out of friends long before you run out of tires.Shortly after that, unless you are wealthy, you run out of money.And when it's all said and done, the house is still a bunch of garbage.Leaky garbage.And in a few years, leaky, stinky, moldy garbage that is too hot in the summer and too cold in the winter.Don't even get me going on his aluminum can walls. <G>Or the kitchen-sink "greywater" system that feeds the garden INSIDE the "house". And I use the term loosely.That guy gave a black eye to alternative building and a sore *## to his clients.
If you was broke , homeless, jobless and living in a landfill then it might be a good idea, I said "Might". 2+3=7
That guy gave a black eye to alternative building and a sore *## to his clients.
LOL I do know several earthship owners who are tickled with their performance. And if you live in the southwest, reasonable resale is a distinct possibility. Michael Reynolds original place sold nicely, if considerable time on the market.
My first experience was digging up the buried wall of a very leaky, very expensive tire house. GC brought in to fix it asked me what I thought. I like concrete. Looked like a good place for a concrete wall to me, right behind the rear tire wall. Didn't happen. A foam contractor sprayed a layer there. Certainly less expensive, now if the carpenter ants leave it alone...
Ever read about Dennis Weaver's tire house? Concrete filled. Inexpensive it wasn't. Believe it was written up in FH.
I'm more sympathetic than you, but the economics of a mortgage are a reality to most homeowners. Not that I'm trying to market to them, but it seems to me an important reality. If not first go-round, then resale.
For water treatment, I'd also go a slightly different way. As any system, it can be poorly engineered. Are you familiar with Biosphere? Not touting it as a spectacular success, which it clearly isn't, but the water treatment apparently worked. One thing I do understand is the value of waste water and effluent. Here, in Virginia, I discussed various possibilities with our health dept. Didn't go far. Grey water is required to go into a septic system. Conservative, but strikes me as wasteful.
To me, alternative architecture is wonderful. Not always successful, but valuable in challenging conventional thinking. Certainly a risk to the owner. As mine was. PAHS Designer/Builder- Bury it!
Glad you saw the humor in that. I hoped that my deep-seated sympathy for alternative methods wasn't obscured.I've built with a lot of different materials, some of which folks might think were pretty funny, but the common theme is you've got to do a good job.I've got no end of patience for experiments as long as they don't hurt anyone financially or physically, but I've got no patience at all for half-a$$ed builders anywhere on the spectrum from hippie to redneck.As for greywater systems, my problem with Reynolds (if this was indeed his idea and not the homeowners') and the earthship concept is he just flat broke the rules. The kitchen sink is no more "grey" than the toilet.Greywater systems are fine if they are done properly. I've worked on plenty of them. But done improperly, you have a first-class public health crisis waiting to happen.The environment department has to work to the lowest common denominator. That's just life. Unfortunate, but true.I'd like to see more greywater systems for the same reasons I suppose you do, but I don't mind seeing pretty strict regulations either. A viral load in the local groundwater would not be a pretty sight.
Re: "I'd like to see more greywater systems for the same reasons I suppose you do" ...There might be more out there than you think. A septic tank and drain field system is a very advanced greywater system in that it effectively handles, treats and reuses both grey and brown discharges. When people propose a greywater system they would do well to compare their design to the simple, cheap, effective and well pr oven septic tank and field. Most greywater systems I have seen or read about don't make the cut because they are not simple, largely self-maintaining, cheap, well understood or demonstrably, by way of a hundreds of years of experience, safe if designed using a few simple rules.
<<Most greywater systems I have seen or read about don't make the cut because they are not simple, largely self-maintaining, cheap, well understood or demonstrably, by way of a hundreds of years of experience, safe if designed using a few simple rules.>>Agreed. The ecological benefits of a properly functioning septic system should never be undervalued.The distinction is seemingly minor, but my inclination toward greywater is that if you exclude the toilet and the kitchen sink, and if the system is done right, you can support non-food plantings, that is, landscape, and potential habitat, with discharge that is still sub-surface, but close enough to the surface to be useful.That's generally a bad idea with conventional septic tanks.
Re: "That's generally a bad idea with conventional septic tanks."I have read two different versions on that:First is that pathogens can be incorporated into or onto the plants and spread disease. Sounded true to some extent. Perhaps better safe than sorry.On the other side many Asian nations, including the very safety conscious Japanese, have used 'night soil' as their primary method of fertilization. Story is that as of a few years ago a group of Japanese travelers could save money by selling their "night soil" and get enough money so that something like one out of five could stay in the inn for free. I'm not sure how it would work out if you turned down the deal. Take it with you? You ask for a 'dogie bag'? What would Homeland security say when they search your bag. So ... Seems there are cultures where they use the sewage around crops. There is the nagging advisory not to eat unwashed vegetables in China but there is none in Japan. Perhaps the difference is that the Chinese dump the pots more directly on the crops. While the Japanese work them into the soil away from the crops and only later spread them around the crops. The soil bacteria destroying any pathogens.Seems to me there needs to be more study. And even if the drain field couldn't be directly under the crops there might be some way of incorporating the leachate into a composting situation. Composting needs nitrogen and carbon and moisture. In return soil bacteria, fungi, and worms turn vegetable waste into 'black gold' and along the way heat the mound to the point it kills seeds. Between the heat and biological free-for-all human pathogens wouldn't seem to have a chance.
You haven't run across The Humanure Book? http://www.weblife.org/humanure/default.html
Chapters include: Crap Happens, Deep Sh*t , A Day In The Life Of A Turd, ...PAHS Designer/Builder- Bury it!
I've seen it.I'd recommend talking with some scientists at Morgantown State University (Small Flows Clearinghouse) and some resposible biologists from someplace that works with water quality before I took anything in that book seriously.What one farm family with their full complement of good old country common sense MIGHT get away with in a sparsely populated rural setting, and what could be permissible in a suburban or even relatively dense rural context are two entirely different things.Let's say you're on 2.5 acre zoning. You're on the south side of your lot, your back-to-the-land dreadlock-wearing hippie neighbors are on the north side of their lot, the land falls in your direction, and there is a light prevailing wind that heads your way.Your neighbors keep a few animals, but they are slobs, don't really know what they are doing with animals, and there are lots of flies.They pick up a copy of the Humanure book at the local metaphysical coffee house and decide it's a good idea, so they start to try it.But a few of them turn out to have several different types of hepatitis betwen them, and after a few months they aren't feeling good enough to really take care of that pile in the yard, but they will pretty soon, so they let it pile up rather than relinquish their counterculture ideology.At the other end of your property, the adjoining lot has a redneck family who couldn't see any reason why they should pay for a septic tank so they buried a station wagon and ran a 4" line from the house to the car.On the east side you've got a guy who has been reading Permaculture books, and buried a vertical 6' metal culvert and ran his house line into that. Ought to work just like an outhouse, right?On the west side you have a little creek, and everyone is on a well.Makes you kinda appreciate the environment department, doesn't it? <G>
Makes you kinda appreciate the environment department, doesn't it? <G>
LOL You've been here? I've given a lot of tours...
There's a reason we live mountaintop, 62 acres remaining, no close neighbors. One side is your redneck scenario, on solid rock. Still don't know how they got that outhouse pit dug. Septic out of the question. He had the audacity to offer it to me last yr for $78k. Deed says 2 ac, but I don't know where it is. Never been surveyed and looks closer to .5 ac to me. Everything great grandaddy owned on the N. side of the state road...
The other side is a nice 3500' house on the market at $1.3m, 18 acres. Must be a tad over-priced for our market as it's been for sale awhile. Run into the owner in the PO, and she smells far worse than the rednecks with no indoor plumbing. This is country living. We love it.
I subscribe to a soil makers list. Trying to learn more about developing our roof, which gets better every yr. One issue they go into is how intensive agriculture can be practiced in one place for thousands of yrs. Modern agriculture is not so successful. So I'm composting, growing worms, and will try no-till this yr. Oh, and continue using the septic system. PAHS Designer/Builder- Bury it!
Re: "What one farm family with their full complement of good old country common sense MIGHT get away with in a sparsely populated rural setting, and what could be permissible in a suburban or even relatively dense rural context are two entirely different things."You make a very good point. What works in at low density fails when the human, or animal in the case of feed lots, dairies and hog farms, population cross the bearing limit of the land for any particular nutrient or component. Assuming decent conditions and one average family per two or three acres septic tanks work quite well if well designed and built with just a bit of regular maintenance. Less well with one family per quarter acre. A lot depends on the soil and drainage conditions. A high water table, inorganic or 'dead soils, and poor percolation lower the bearing capacity of the acreage. A more complicated design, like a raised bed and grinder system, can make marginal situations possible but not without added cost and complication. A failed grinder pump or washed out raised bed can make quite a mess. A mess that can easily wash into waterways and become a major hazard.The Japanese may be worth studying on many such issues. They have a modern society, an effective health care system and a high population density. The US is facing changes in land use and population density. The way we have done business in the past won't work in most places. The option to, as the story goes about the guy who lived so far from anywhere he could 'take a dump off the front porch', has expired. Your front yard is someone else's back yard. Every square foot of land is accounted for and every gallon of ground water allocated. Where to get fresh water. What to do with out wastes. How to keep them separated. These are problems that man has faces from day one. We like to think we are advance and somehow above such concerns but such basic concerns don't go away. As there are ever more people and ever less suitable land available it is going to be a problem we will be seeing more of in the future.
Good points all the way through.<<We like to think we are advance and somehow above such concerns but such basic concerns don't go away. As there are ever more people and ever less suitable land available it is going to be a problem we will be seeing more of in the future.>>Dead on.As industrialization insulates society at large from such concerns, and the less each of us thinks about them in our daily life, the more stunned we will be when something goes wrong.As an urban society, we are so removed from basic concerns because we can take them for granted. It seems to me that while centralization and automation are certainly effective and efficient, this has also replaced some level of functional redundancy that permeated agrarian society.In my opinion a lack of organizational or structural redundancy generally indicates some level of systemic fragility. Something for urban planners to consider, anyway.
"What to do with out wastes. How to keep them separated. "
Reading this thread, I am liking my town more and more. We have a city sewer that goes to a sewage treatment plant. After treatment, the water goes into the secondary irrigation system for landscaping and crops. Having the city manage the treatment means that I don't have to worry about my high-health-risk neighbor composting his manure properly.
This also generates a nice revenue stream for the town: they charge us for water used, the water usage drives the sewer bill, and in the town proper we pay a flat fee for secondary irrigation depending on lot size. Once you get into the farms, the irrigation is based on water shares, but the water comes from the same pot.
After treatment, the water goes into the secondary irrigation system for landscaping and crops.
Which makes sense, as most of the regs on waste water treatment often have the treated water cleaner than "natural" water (as some facilities along river have found out the hard way).
My county is defined by two rivers, one east, and one west. Municipal water is drawn from wells in the north (ever farther north, too, due to salt encursions) of the county. But al lthe waste water is passed back to one river or the other. (We need a dam on the Navasota for flood control almost as badly as we need an impoundment for drinking water--but land speculators keep ruining the project every time it's been fronted in the last 25 years.)
So, we pump water out of aquifers, which then recharge through sinclines across salt domes, which then kills the water quality and a new well is needed. All to pump the used water into a nearby river so it can flow to the sea. Occupational hazard of my occupation not being around (sorry Bubba)
All worth thinking about.The viral load is the big short-term concern. As you pointed out, better safe than sorry.Couple other concerns, too. Nitrogen loading in the surface water can be a catastrophe. Blue baby syndrome in a community is an ugly spectre. So any surface or near-surface discharge needs to look at that, particularly if there is a chance of surface or near-surface runoff.As for night soil in agriculture and any other surface discharge (as in Mexico, for example), I know it has been done, but can't see it as a responsible approach.Besides the fact that we are no longer a primarily agricultural society, many other factors have changed. For example, the diet of everything in the food chain.If you look at the result of trophic concentration, I suspect our "night soil" isn't what it used to be. This seemingly minor factor may actually be the one that gets us in the end.If one could figure out how to remove the heavy metals, hormonal analogs, and the rest of the long list of pollutants that either did not exist or did not exist in these concentrations 50 years ago, we'd probably have something to work with.
Reminds me of a pic on the back cover of a mid 80s FHB. A home made of glass beer bottles. If I remember the story was about an island where lots of beer was consumed. A beer company made glass bottles that could be used as brick. I think only one house was built.
Probably because the owner and consequent future owner / builders became "good for nothing" alcoholics before the roof went up. Nobody finished and the walls were pretty crooked, but they sure had fun.
I remember that backcover, it was Aruba IIRC and they were Heineken bottles.
<<BTW - I heard that CloudHidden, VA Tom and JunkHound were starting an alternative building forum - now Nuke wants to join too... should be some good info over there... >>Got a link? Sounds interesting.We will bankrupt ourselves in the vain search for absolute security.
-Dwight David Eisenhower, U.S. general and 34th president (1890-1969)
Unless you have some high ground an underground could be problematic. That is unless you design the house like a submarine, itself not entirely a bad idea, and include provisions to keep it from floating as the water level rises. A lot of bomb shelters built in the 50s had a habit of 'popping up' like mushrooms if the water table got too high. I understand it happened quite a bit in Texas. I also read the alternative, flooding, happened in a large multi-million dollar bomb shelter. Hard to say which is worse.How you get or build a submarine or its equal, move it to the location and keep it from slapping around or floating are not insurmountable obstacles.I have often thought about using barges ashore. Anchored so they can float and pivot but not go far they would rise up with storm surge or flooding. A low and sturdy structure could be built on top and the barge could be recessed into the earth to disguise its presence. Lots of open space inside even a medium sized barge. Might make a decent community shelter. Or a hedge against TEOTWAWKI for a family.On the down side if the hull rusts through your dream ship could be taking on water about the time you realize it is too late to flee to higher ground. Also barges make dandy battering rams. If the scope of the swing is too wide in the anchoring system the neighboring homes may not be just flooded but flooded and crushed. If the anchors drag or fail entirely the path of destruction could easily multiply.Another reconsideration being that joyfully flattening a neighborhood won't make you very popular but, on a personal level, it is also unlikely to do the hull any good. Playing tank with the peasants huts is good fun but having a hut hole your dreamship could ruin your whole day if it happens while the water is 20' deep and the wind blowing a smooth 120 mph.
You've already got a concrete house, but you didn't design it for burial. Don't even need a hill to dig into.
In Saginaw, Michigan, there's an underground house on flat-as-a-pancake land with a hill piled up over it. Looks odd, but I understand it works well. Pretty sure it wasn't PAHS. Lawn on top like the teletubbies. Nobody home when I was there so I never spoke with the owners. Built maybe 20 yrs ago.
In your locale water's the big issue, if the house survives the wind. Higher elevation clearly better. We had the top 50' of a tulip poplar tree come down on our roof when Isabelle came through here. Didn't know about it until I found it the next morning. No damage, just a winter's worth of firewood.
Big flood here a few yrs ago, washed out highways. Got a call from Dutch friends, worried. They'd been here. Cracked me up. We're 400' (elev) up the mountain. It'd take a flood of biblical proportions. Livin' is easy.PAHS Designer/Builder- Bury it!
I,m at elevation 80 so not really wotrry about flooding. thirty miles from coast now. it just high wind. would't mind going into ground about eight feet and bridging over. I just worry about losing the roof during these storms. even thought about a little storm shelter underground if I could just figure how.. 2+3=7
Re-engineer your roof and import a pile of fill? Didn't know you were that high.
You could bury a (dry) septic tank and add a ladder.PAHS Designer/Builder- Bury it!
Years ago they built a dome theater in Woodland Hills Calif. Probably around 1964. I was in Jr High there. They formed a dome of earth..formed on top of it...and then excavated the interior. Seemed to work well. Saw Vincent Price as Captain Hook in Peter Pan there.
Does it help to have a sloping site? I want to remember (from a couple of decades ago in all fairness) that having about one storey's worth of slope made it much easier to accomplish.
It's not something I've ever really gotten to explore, only 'getting' sites that are either flat, or stuck on a rock cliff face of some sort.
Is there a good PAHS 'answer' where the site only has about 4-8' of slope in it (that is not some form of earth-berming/sheltering)?Occupational hazard of my occupation not being around (sorry Bubba)
Does it help to have a sloping site?
Is there a good PAHS 'answer' where the site only has about 4-8' of slope in it (that is not some form of earth-berming/sheltering)?
Good questions. When you excavate you get fill (duh!). When you bury you need a lot of fill. More excavating gets more fill. Somewhere in there you can encounter extreme excavating costs, then it's better to import fill. How's that for a non-answer?
I felt pretty foolish paying a guy to do nothing all day but haul tandem loads of dirt to the top of this mountain and dump it out. But my excavation was only 6' deep (to zero). Took a whole lot more dirt to cover the thing. Really tall house didn't help.
The client house site was somewhat steeper and we didn't need to import any dirt. Same height house. The Saginaw, Mich, house (not PAHS, but buried) had to import all the dirt for burial.
What makes PAHS work is to spread the insulation umbrella out 20' from the perimeter. Here, that means under the front patio, side yard, kitchen garden. The building inspector looked at me like I was from Mars when she realized where I was burying insulation. Offered to explain, but she didn't want to hear it. The reason for the 20' is that's how far heat moves in dry dirt in half a yr. You dump it in the summer, get it back in the winter. The mass is close to interior temp the whole time.
More mass is better. We're under-massed according to the author. And our house under-performs accordingly. We get a 13º annual temp swing. He got 7º. We'd do ~5º better if we bothered with window coverings. Well, we really don't mind what we got. By far the most comfortable place we've lived. It's a continuum, mass/performance. He envisioned buried domes. I bent the walls, and umbrella, considerably. Nothing broke.
The buried air tubes the author found important scared the bejesus out of me with our humid climate. So I didn't install any. Arid climate, I would have. Maybe they would have made up for our relatively small mass. Don't know. They would have precluded our active ventilation system.
I've bumped into some who worried about failure with a relatively unknown design. But the risk is almost nothing. If we got 2º colder in here winters, it's not a lot of supplemental heat to worry about. Or in your case, primarily a cooling climate, an extra couple º in the summer wouldn't take much AC to alleviate. PAHS Designer/Builder- Bury it!
That's quite a house, thanks for the link.
I like the use of commercial materials in residential structures when done appropriately, which I think you have. I remember studying similar housing types when in first in school back in Canada in the 80's. Did you do this type of work in Colorado first?Maybe you could get CU and Sphere to dress up your copper.<g>
Off topic a little....but....heard this a few weeks ago and I'm still thinking about it....60 million people around the world live completely underground, 40 million in China alone, mostly in modified cave systems. Apparently very comfortable, and maximises the use of the arable land for agriculture.Cabinetmaker/college woodworking instructor. Cape Breton, Nova Scotia.
Did you do this type of work in Colorado first?
No, only read about it. Book, "Passive Annual Heat Storage", was published in '83 based on a house in Missoula, Mont. I'm was/am a professional furniture maker. Concrete appealed to me, simple to work, won't rot, and bugs won't eat it. Why make houses out of bug food?
Maybe you could get CU and Sphere to dress up your copper.<g>
I knew nothing about copper, or building, when I started here. This is my first effort. Plan was for this place to be my furniture shop (Slogan: "I'm not expensive but I make things that are".) and, when we got the money, to finally build the house we really wanted, now started. I wanted a location, and shop, that would encourage potential clients to open their checkbooks. Pretty sure I succeeded, even if I'm not accepting commissions. This place was largely a business decision.
Copper only happened when my stucco guy left the area and I learned what stucco normally costs. A contractor friend (who would like a house like this but in early Frank Gehry style, Santa Monica) suggested that as I'd done a small copper roof on an outbuilding, why not sheath the house in copper? Made sense to me, not that I knew what I was doing. Bear in mind that a leaky skin makes little difference if there's nothing under it to rot. Copper strikes me as cheap, both as siding and roofing.
DW went along with my dreams, knowing that this was "temporary". After a decade here, she wants pretty much the same thing, but with guest suite, sound-isolated office, large garage, and indoor lap pool. Modest tastes. It's started, just over the hill here (better view). Then a rental agent friend enlightened me as to rental potential here. I've been bought.
Soooo, the next house. Then I finally get to build my dream shop (again). By which time I hope to still be ambulatory enough to consider furniture making. Hoping to bypass bar joists next time in favor of thin shell concrete, underground of course. The work of Felix Candela knocks my sox off. He had cheap Mexican labor and wood forms. I favor dirt forming ala Paolo Soleri at Cosanti. Don't do well with crews, but I have tractors that'll move a lot of dirt. And a 50 yr old Linkbelt crane to lift concrete buckets.
Livin' my dream. And way more than you asked for, sorry. That page was put up by a guy in Florida after exchanging emails and photos. Big surprise to me. If you want to read about PAHS, here's an excerpt: http://www.axwoodfarm.com/PAHS/UmbrellaHouse.html
Your mention of commercial materials is very appropriate. That's all this place is, beefed up for the earth loads. The reason you see bar joists on most commercial buildings is economic, same here. Wood doesn't compete.
PAHS Designer/Builder- Bury it!
Well, your ceiling probably isn't quite the same as ours
Yours looks like the ceilng at Home Depot.
Cool home, especially appealing: requiring neither heat nor ac.
>>Yours looks like the ceilng at Home Depot.Hopefully he doesn't light it the same way.
Yours looks like the ceilng at Home Depot.
Exactly. And most other commercial buildings that don't bother with a drop ceiling. And the reason is..... cheap. This whole place is commercial construction, beefed up for the earth load. Well, maybe not the curved walls and arch topped windows and doors.
The client house got a finished ceiling, not drop. It was stamped metal, drywall, or wood, depending on room. One thing that became apparent fast was the ease of wiring and HVAC ducting through the bar joists. Saved even more money. Like here, it got copper cladding, including the windows. There're several reasons the appraisal came in 50% higher than construction cost. Substantial instant equity allowed the owner a lot of leeway.
Our place was designed to be my future furniture shop, but now destined as a rental. Our next house may have finished ceilings, undecided. We kinda like what we have. My only complaint is that I like compound curves. Difficult to do that with bar joists. That's my sole interest in thin shell concrete.
Cool home, especially appealing: requiring neither heat nor ac.
Seems reasonable to me to expect a house to take care of you, not the other way around. That means low initial cost, zero maintenance, zero utilities, comfortable without the occupant doing anything. We're not quite there, but close.
Nuke had a thread recently about his discomfort with the power grid being down and the house cooling off. Ours doesn't. PAHS Designer/Builder- Bury it!
Wonderful. I am also a Design / Build company, but have not ventured too far form traditional construction.
It is healthy and inspiring to see someone venturing into alternative building methods with success.
Was going thru my library the other day and saw an old hippie book from back then titled something to the effect of 'The $50 Underground Home Book'.
Had a slew of old b&w photographs of guys in flared leg bellbottoms digging stuff by hand.
You ever had opportunity to meet the author?
be not that I'm trying to insinuate that yer an old hippe:o)
'Nemo me impune lacesset'No one will provoke me with impunity
You know the cliche: "if you remember the 60's, you weren't there"? I've got a few gaps. But not particularly hip. Then, or now. DW and I did head off for communal living (overseas) once. Didn't take. We're still we.
Had to search (don't Google) Oehler to see what he's been up to. Never met him, but I'm relatively late to the party. Nor do I have a large enough ego to try to change the world. Clearly, $50 didn't buy much concrete at the time. Wood foundations didn't/don't do much for me. I like concrete, not that I agree much with Cloud (obviously- wasn't a conversation). Interesting discussions occasionally on the alt arch lists with the concrete police. You might enjoy tuning in. Not that I'm any more interested in arguing there than here. Conversations are wonderful. Pontificating is just that.
I've got a few interesting client things going now. One is the place I cut the driveway in through the boulders. Ideal spot for an underground house. Client requires conversion but I earned immense credibility with them already. Another is my machinist (retired) who wants to build a house for his daughter. He at least is more than willing to discuss heating/cooling costs and problems with the grid going down.
When you have a house that keeps you comfortable year-round without you doing anything (passive), costing little to build, nothing to maintain, and almost nothing to operate, it's bound to be interesting to some. Here, as everywhere, the majority will claim that "reasonable" heating/cooling costs are perfectly adequate. That's fine, long as the grid is working and you don't mind the bill.
What makes more sense is to look at lifespan costs for heating/cooling. It'll be substantial. Common experience is to spend 1 month's income/yr for creature comforts.
I'd rather have that month for myself.
I also find these spheres wonderful, if not underground. Next time leave the 2x's at Lowes, concentrate on the plywood. Get hip(er).
PAHS Designer/Builder- Bury it!
Tom,Can we find common ground? I like what you do. I like what I do. I don't need it to be competitive. We have much more in common than not. You represent your own stuff, and I'll do the same with mine. Big world, many options, clients will decide what they're happiest with. Writing a check lends some clarity to decisions. So do wives. <g>I'd be equally happy to show you around mine as to be shown around yours. Fine Homebuilding is my current passion, not round v square. Cool? Jim
'Nemo me impune lacesset'No one will provoke me with impunity
For Milena people have built homes in Tunisia that were largely underground. Most people have seen at least one depiction of the basic design when they saw the first of the Star Wars movies.
As I understand it the home shown was a real Tunisian home that had been modified to create the Hollywood creation of a futuristic Tatooine moisture farm.
The basics were that the house was built on, actually mostly in, a desert plain. The majority of the home is underground with only a bit of structure above the ground. Notably a common Tunisian feature is a small 'wind-catcher' structure that may include an evaporative cooling system.
The basic of the hose is a cubist toroid centered on a relatively narrow but deep central courtyard. The central court providing ventilation and light while the surrounding earth buffers temperature extremes. The Romans in the same area would sometimes incorporate a fountain in the center of the courtyard. A lot depends on how precious water is locally.
Such a design is imminently suited for many deserts. I think it might be suitable, with some modification, for many other locations. I'm not sure how a recessed central court would work with three feet of snow on the ground and drifts, above ground, rising to six feet. Seems to me that courtyard might pretty well fill up.
A critical failure if all exits are in the central court. On the up side, assuming you still have some way out, a central court filled with snow would be decent insulation and, once it warms, the melt water might be useful. I have read that Tunisian underground homes usually used the central courtyard as a central collection point for an extended rain collection system. The courtyard would drain down into a cistern.
Another 'underground' home is sometimes seen in mountainous areas of the caribbean. I have only seen drawings and pictures but the main feature of the type is a large overhanging concrete slab held up by cables or chains. If a storm or hurricane threatens the restraining chains are loosened and the slab is allowed to tilt forward sealing the front of the house from the wind. Either off to the side or on the reverse slope there is a smaller door allowing access.
Ya just start digg'n!
http://www.roadtripamerica.com/places/forest.htm
Saw that place on an HGTV show. Pretty neat when the tree's canopy is at ground level. Makes it easier to pick the fruit.
jt8
"The test is to recognize the mistake, admit it and correct it. To have tried to do something and failed is vastly better than to have tried to do nothing and succeeded."-- Dr. Dale Turner
It's certainly possible. I've done bermed-in ICF houses (no different than a New England basement with a roof) and the thermal performance was amazing.
There are plenty of pre-cast concrete products that could serve as a roof (I guess you'd call it a roof), I suppose Hambro trusses could also work well.
I'd have a hard time with no natural light or ventilation, but that's just me.
Someone built a house on Vashon Island, WA by piling up a huge "dome" of dirt, building a "structure" of rebar, shotcreted the entire thing then dug it out with a skid loader.
I was never in it, but I saw it in progress.
Life and suffering are inseparable.
That's Soleri's Cosanti (Scottsdale) method. Then if you move the dirt on top of the dome you have the best of both. I'm not fond of domes, but a hyperbolic paraboloid would be nice.PAHS Designer/Builder- Bury it!
Goreme, Turkey -
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Great pix. Yours?
One of my great disappointments was not getting there. Had intended to drive around the Mediterranean to Israel. Unfortunately Turkey had a hoof-and-mouth (foot-and-mouth) epidemic going at the time, making travel all but impossible. So we also missed Petra in Jordan, the cliff city famous from Indiana Jones' "Last Crusade".
Cappadocia's an old lava flow, making the excavation pretty simple. Another part of Turkey had "cities" going down 10 stories underground.PAHS Designer/Builder- Bury it!
Wow, a lot of great information! I would have responded sooner, but shortly after my last reply yesterday my computer monitor died. Doing this on another computer, and a great morning read.While my original intent was completely enclosed structures (a house completely underground), I can see where a happy, an effectively performing, compromise between the physical health and the mental health can be accomodated in some of these designs.Tom, you posted a reply to another discussion of mine about two months ago when I was looking at means to span 40' ceilings, and you replied with those bar joists. Really loved that bit of information. Now, I am curious as to why the chosen dome design was appealing. Are domes always a best trade-off of structural integrity vs. volume utilization for a given budget?I do like concrete, and some in the past year have showed me how concrete can be made to not look ugly. Its interesting how your wife's initial and current opinion differs. I had the same thing happen when I converted a bedroom into a miniture bat-cave theater room complete with a 140-pound CRT projector hanging over her head. Initially, it was "no way!", but fifteen minutes into watching a movie on a 92" screen and she loves it.Now, the WAF (wife approval factor) can always play into one's dreams and core ethics. Glad it worked for you, but I hope the development of further designs isn't under the same constriants as we faced. Now, I do wonder exactly how difficult it would be in some geographis to actually excavate, say 5,000-10,000 SqFt down to about 50' depth, build, cover, and decorate.Also, I did visit a website that someone suggested in one of the first two replies to my original post. Some of the green-grass coverings made me wonder how a landscape above being water-cultivated could effect the performance of the home underneath.
Now, I am curious as to why the chosen dome design was appealing. Are domes always a best trade-off of structural integrity vs. volume utilization for a given budget?
I'm sure Cloud will have something to say here. I'm uncertain, but my gut feeling is that thin shell will not compete with bar joists. Clouds domes and my experience are apples and oranges. His published costs are considerably higher than mine, but that isn't necessarily due to the difference in construction. My interest in hyperbolic paraboloids is primarily esthetic.
One area where we disagree is dirt-forming. I see substantial benefit over air-forming as it can preclude the skilled team ($$$) required for the Monolithic method. I never have skilled help. The client house was me and 2 college kids, who knew nothing. What I don't know is the quantity of steel reinforcing required for, say, 300 psf loading. I can make a pretty good guess as to labor differences between bar joists and rebar in dirt-forming. Bar joists are fast, really fast, with minimal low-skill labor. The thin concrete pad on top doesn't have to be finished beyond screeding. For a buried dome, you need no top finish, and have no coating to deteriorate.
While my original intent was completely enclosed structures (a house completely underground),
Right, I understood, which is why I didn't originally respond. You were thinking cave. Davis Caves are more in that line. They're widely available. DW was responsible for our large windows, also the source of my primary design difficulty, glazing. I'm hoping for aerogel to come online.
You mention mental health. We'd be living in Norway if it weren't for the dark winters there. Much larger problem for her than me, but we needed a bright house. And got one. Yesterday at lunch we had to trade sides of the table, too much sun, even on an overcast day, for her (not normally) strained eyes. She needed to face our buried wall. Generally not an issue.
One thing we get with this massive heat sink is freedom from overheating this time of year. Take a standard low-mass house, add our glazing, and you'd get uncomfortable temps fast on a day like today. We change maybe 3º in a 24 hr period. Doesn't matter if the electricity works or not.
I do like concrete, and some in the past year have showed me how concrete can be made to not look ugly.
Concrete's a fluid, can be made to look like just about anything. I built a big box here, suited my skills and finances at the time. Envision your ideal house.... it can be concrete.
You want to put 40' of dirt (50' deep excavation) on a roof? That's an incredible load, where a dome might very well be a lot cheaper than bar joists. Pretty sure you'd do better to acquire an old mining claim and move in. Not that you'd have a comfortable house, far from it unless you like mid 50's temps.
We have a green roof here, no issue for the thermal performance, which happens well below the greenness. Our roof mass is topped with XPS and layers of 6 mil poly. On top of that is a foot of dirt to grow whatever. Raised veggie beds and raspberries in our case. Not a bad location for croquet, if that's your passion.
PAHS Designer/Builder- Bury it!
Tom, I'm not trying to make a case for one house style over another. There's plenty of room for many varieties, and a case to be made for each.I would take a stronger stance on forming methods, though. The engineers I've worked with who prior dirt-formed are now air forming be/c it works much better for them...it's something we've discussed in the past. I assume a similar crew and similar quality result, or else any comparison would be pointless. Just like we can't compare the cost of a Mike Smith company-built house to a Sphere self-built one, be/c labor accounting, reclaimed material, etc will all be different. Comparing a contractor-built air formed to a you-built PAHS or a self-built dirt formed isn't the proper comparison. On the money saving side, I know guys who pack the mud on by hand and make their own air forms from recycled (free) billboard material, but I don't factor that into my pricing estimates. I only assume a professional crew with a proper contract, and with that, dirt forming would not be as economical, wouldn't be as quick, and wouldn't be as easy to achieve the same results.> structural integrity vs. volume utilizationI don't focus on that be/c while geometry offers an opinion, that's not why my clients choose those houses. They like the sculptural shapes, the energy usage, and the strength. Other buildings offer their own shape, energy consumption, and strength. Clients choose the combination that best tickles their fancy.Now, that is a great reason to chose a dome for industrial uses--grain storage, salt domes, etc--but for residential, if someone is that far down on the list of reasons to choose for or against, then the sale is already lost.
I understand your forming opinion. Your contractors have their own perspectives.
From mine, I've got loaders that'll move a lot of dirt in a hurry. Don't have, or want, a skilled crew (way too much overhead). And dirt-forming makes less sense if you don't have a subsequent use for the dirt, burial. But this is very different from talking about a Mike Smith house and Sphere's homestead. Poor analogy. Labor's labor, whatever it costs. For concrete work, I'm not recycling anything. Strictly man-hours and material cost.
Comparing bar joists and cast walls, however, is direct. Real common in commercial construction. Easy to compare costs. I also know what my client house cost him, and what you've posted.
The question here was what's the cheaper way to get an underground concrete house. To date, I know of nothing anywhere close to what I did.
I got dropped, for some unknown reason, from the fc list. Didn't complain as my primary interest was underground, unlike pretty much everybody there. Didn't make it to Oregon to see the failed PAHS dome, which I regretted. Neither the hand mudders nor Nolan's spray crew moved me to emulate.
You figure out what you can do and proceed accordingly. I like most of Candela's approach. He was beating the financial sox off everybody.PAHS Designer/Builder- Bury it!
>The question here was what's the cheaper way to get an underground concrete house. To date, I know of nothing anywhere close to what I did.What are your _shell_ costs per sf? (footers, exterior walls (how thick are yours?), roof, structural steel, what else?) We counting insulation or not? I'm assuming these things are proportional to structure size, yes? There's a pretty direct relationship in our case.I'm also assuming that plumbing, elec, windows, doors, interior walls and finishes were identical be/c they're unrelated to structure, yes?Is that a fair way to deconstruct this?
>>I'm also assuming that plumbing, elec, windows, doors, interior walls and finishes were identical be/c they're unrelated to structureWouldn't some of the plumbing and electrical actually be slightly more expensive, where it gets encased in the CIP walls. WIndows and doors would require some preplanning such as cast in nailers or would have to be fastened to the conc. walls. Also would the perimeter walls be furred out or is the inside surface of the concrete treated in some manner.Would some of these issues also apply to the thin shelled structures that you do?
My perspective is that the costs would be similar for a CIP and a thin shell. In each case you have to provide for doors, windows, elec, etc, but I don't think that anyone's saying one method offers savings there over the other. Plumbing, for sure, be/c we don't put any plumbing in the exterior walls. For wiring, it's just gray conduit where needed, and then pull wires later. For doors and windows, V-Buck or PT buck, and then don't put rebar or spray concrete there.Some of this is certainly different than with a frame structure, but should be more similar than different for CIP, ICF, Tridipanel, air formed. We do as little as possible in the shell, except for structural stuff.
I remember seeing a program about this innovative system used in Israel. I forget the specific term describing it, but essentially it was a rigid insulation panel system that was erected and sprayed with gunite or something similar, inside and out. Rough openings for windows and doors would be cut out in place. Since the panels were somewhat standardized, empty conduit was pre-installed and in theory would align. Philip Johnson also had a pavillion built on his New Canaan, CT property adjacent to the Glass House that employed similar techniques.
http://www.greensandwichtech.com/company/panels.php and http://tridipanel.com are similar to what you describe...what I call a shotcrete sandwich. A problem with them, according to one builder who's built with 'em, is that the welded wire allows an objectionable amount of heat transfer, especially in winter. http://www.thermomass.com/index.html has solved that with a low-conductivity connector, but they primarily do factory built panels rather than site sprayed.I've speced panel systems like this for flat walls set into our curved shapes. I prefer them to ICF.
Do you have the engineering for thin shell, 300 psf total load? That's something I'd really like to know. No way for me to compare costs without.
We counting insulation or not? I'm assuming these things are proportional to structure size, yes? There's a pretty direct relationship in our case.
Insulation, sort of, but steel is sold by the pound. But when you buy larger items, the price/lb goes way down. I was shocked, for instance, that my 30' bar joists cost nearly the same as the client's 40'ers. Major economy of scale.
I tried, unsuccessfully, to get into past email programs to find cost comparisons, with Nolan in particular. Assuming you know him, your ITSA host the first two yrs. BTW, did you see his castle? Under construction when he and I were talking. Been awhile.
The cost issue came up often on the fc list. Onebone claimed $4/house sq ft material cost for thin shell. Unsure if anybody took him seriously. I didn't. For the last 2k sq ft house (26k cu ft, which is the important number), we came in just under $22/ sq ft for the shell, including the floor. Today would be closer to $28. Nolan was nowhere close.
This construction is a simple walkout basement, without the house, 8" walls with 1x2' footings and minimal steel, except for the rear wall. It's 14" thick with almost 9' wide footing, lots of rebar. Think retaining wall with 15' of dirt.
Insulation (XPS) for that house, if you want to consider it, was 12k bd ft, $7.1k installed, or $3.55/sq ft. A little difficult to separate insulation labor from burying labor, but I made a stab. Not a lot of money either way. The amount, and type, of insulation for any house will greatly change the cost, and comfort. Very easy to get into diminishing return. But if you want to compare performance, it's important.
As I mentioned, a bar joist ceiling greatly reduced our subsequent system costs.
How're we doing so far? You didn't post your costs. Apparently I go first.PAHS Designer/Builder- Bury it!
>Do you have the engineering for thin shell, 300 psf total load?What's the derivation/assumptions of the 300? All the plans I have handy list wind loads and more typical live/dead loads. They also list depths to which they can be bermed without modification--different for different designs--but I don't have one specifically for 300 here.If anyone was saying $4/sf, they were high [edit: "high" as in smokin' something]. But also, Nolan's project ( http://nolan.itsa.info ) isn't a good one for comparison. It has so much unique and detailed hand work that render it inappropriate for extrapolations. It also had only one small air formed part, and it's hard to get apples-to-apples when comparing insulated thin shell to some of the ferro stuff...the resulting energy performance is so different that meaningful cost comparisons are tricky.The other part that I'm uncertain of here is what overhead and profit are included in the numbers you (and others) might give. But out of politeness I'm not gonna ask. <G> Are the numbers given just the raw costs, or are they the cost as billed to the client?Here's the way I calculate: the easiest match to your 2k house is a 50'D air form. If a 20' tall oblate ellipsoid, then it's 26k cu ft. Fair enough? The surface area is 3416 sf (I use ssf for surface sf). The floor area is really 1963, but close enough, ok?Shell costs are almost directly proportional to ssf. Air form, foam, rebar, concrete directly correlate to ssf. Air form would be roughly $2/ssf. Now some people, such as Nolan, would make their own from recycled billboard material for maybe $100 material cost...don't know labor on it. Foam would be 3" thick at...what's the going rate installed?...$.75/bd ft. Rebar hangers would be $.25 each for one per every 1.5 ssf. Some people would make their own for about $.03 each. Rebar is typically 2#/ssf. Each man should be able to hang at least 1200#/day. Concrete is 4" average, with the mix being a rich one at maybe 20% above the typical poured mix. Crew of 4 should be able to spray 20+ yds/day, so this would spray in two or three days. Footer is typ 1' wide, by whatever depth...2' wide depending on soil and load.I'm gonna skip the slab, be/c that would be the same regardless of structure, right?Most labor is unskilled...hauling hoses, moving material, etc. The nozzlemen need to be good, of course. So what labor rates do we use? Dunno. What overhead? What profit? Should we assume them to be identical...hard to compare if we don't.So, those are the shell costs. Insulation is practically identical in our two examples. Sizes are identical. We have air form costs. You have forming costs. You're doing 8" and 14" poured walls. We're doing 4" sprayed walls. I don't know your rebar. Ours is 2#/ssf.Help me understand any major differences in end cost, be/c I'm not seeing them. You're using twice the concrete; what are we doing in excess of you?One I designed that was built two years ago cost $12/ssf, or roughly $20-$22/sf for its shape. That contractor has upped his prices, but it's the markup/profit side that was upped the most as demand increases. Most good shell builders can get $20-$25/ssf these days, which includes nice profit. The actual raw costs are as described above.Whatcha think?
Edited 1/7/2006 8:20 pm ET by CloudHidden
OK Jim, hit this first thing this am. Too early to concentrate.
No "assumptions" on 300psf. That's what my engineering is set for. Dirt's heavy, wet dirt's much heavier. PAHS built to the author's spec would be considerably higher loading, which I haven't done for economic reasons. There's a huge difference between piling dirt against walls and on top of the roof. Different engineering required.
One's a retaining wall, the other has to do mostly with deflection. 1/360 is ours. That's 1.33"/40'. Bar joists don't mind. Pretty sure thin shell doesn't either. There were a couple of thin shell school domes in Richmond, Va, that sagged so much they had to be razed. No earth loading.
but I don't have one specifically for 300 here.
Nor do I, which prevents me from even making a guess as to my dirt-forming thin shell costs. If the steel/shell thickness isn't prohibitive I can see savings over what I'm doing now. As I mentioned, my only assumptions about air-forming were hearsay. What I can easily do with bar joists is to increase loading to, say 450psf. Simple to compare cost/benefit that way. Our place works pretty well, but we're under-massed.
I wasn't using Nolan's castle work for pricing. Don't remember his even mentioning it. Unlikely, as it wasn't what the list thought of as fc. What I was referring to was his chiming in with spray costs, whether on air-form or ponds. There was also a guy in Hawaii doing a lot of spraying, don't remember his name as we never corresponded.
Had an opportunity to pick up a functioning gunnite rig for the price of the trailer under it awhile back, $1k. Thought seriously, and passed. I like machinery, but that required a crew accustomed to working together. Too much overhead.
Client costs are the only thing I talk about. Was hoping somebody else would weigh in on my high prices. I don't have metal forms, makes my labor cost much higher than for somebody who does enough wall forming to justify the overhead. No way could I compete with the guys who do subdivisions here. I'm much more expensive. Not much labor difference for the one thick wall. Doesn't take long to tie the steel.
My slab inclusion is due to using the same guy to do the inside and the roof. No good way to separate as it's a combo, not simply more sq ft. Took me a couple of subs to find one who knew how to think enough to understand what I was talking about. I'll spare you the details.
Help me understand any major differences in end cost, be/c I'm not seeing them. You're using twice the concrete; what are we doing in excess of you?
Man hours. Or perhaps cost x man hours. I'm the only skill guy and paid very well, thank you. No desire to gainfully work more than a few months/yr. Labor here gets paid $10-12 for somebody willing to work. Overhead, obviously, considerably more. Keep those hrs down and the cost stays low. I don't do enough work to keep a crew, which actually raises my cost when I need one.
Clearly I'm using more concrete, though actually less on the roof. I keep hearing how expensive concrete is but I'm not buying that argument even as we approach $100/yd. Strikes me as a very cheap way to build. Material is never the majority of house cost. You know that.
If I was doing much of this I'd either buy metal forms or sub out to somebody who had them. Would lower my costs considerably. As it is, I like using plywood for the design flexibility it offers, plus the lower overhead. But my unit cost is higher.
One factor you forgot, which probably precludes Monolithic style forming. As you've pointed out, you want the mass inside the insulation. Now you're apparently talking about putting all the dirt mass outside your insulation. In that case, you're wasting the dirt. Won't ever get annual heat storage. And without my insulation umbrella, I'd have to buy water-proofing, probably similar cost to what you now use. This is all directly related to shell cost.
Without the bar joists I couldn't come anywhere close in price, why I keep harping about them here. Had an engineer design cast-in-place tee beams for me once. Now I know why nobody does that. I know what Soleri was doing with dirt-forming. I've read about what Candela was doing with wood-forming. There's an interesting combined opportunity there that I'll explore one day, substituting machinery for Candela's cheap labor. After spending some time at the local U.- our PEs are incapable. I understand your guy stays very busy with large projects.
Your numbers make sense to me. Guess you didn't cross paths with Onebone (the old $4 guy) in Oregon. He's a trip, lives in LA, maybe 80. Would've been memorable for you. Favorite line was "domes suck". <G> Along with his idiosyncracies he had some pretty interesting ideas/observations. Ever hear of a Onebone mixer? May be pushin' daisies by now.
PAHS Designer/Builder- Bury it!
Agreed that concrete costs aren't having a huge impact be/c it's not a huge percentage of the overall. Same with steel.Typical crew for our stuff only has one high-labor person, too. Worked with a crew this summer...one boss and 3 laborers, guys who were good with a trowel, but still only cost me $12.50/h each to "borrow" from the the boss, with him covering all taxes, etc for that. My house had just the shell guru, a laborer, and me (a gofer at the beginning). So the labor situation is similar.I agree that air formed as typically done doesn't have the dirt as a heat sink, and I understand how you use that to effect with a PAHS house. Our general approach is to inquire why the structure needs to be buried, be/c there are costs to doing so, and few advantages to doing so that would outweigh those costs (with our structure). So you do that by definition, while we aim to provide the same benefits above ground, but can bury if necessary. Vive le differencé (pardon my French).Don't know anything about the schools in Richmond. Links? No properly engineered structure should do that...curious what the story is...and the specific technology...if air formed, I usually tend to hear.I'll ask my engineer about the loads for burying...Don't know Onebone...the ferro guys tend to stay all to themselves, both in person and online.Gunnite requires more expensive machinery and more skill than shotcrete. Few are built with gunnite. Most are shotcrete, which just needs the pump, a nozzle, and a compressor...and a bunch of practice to do well.So much seems the same or similar...insulation, steel, concrete, labor (I don't see a difference in labor requirements)...I don't see how the bottom line costs would be noticeably different.
compacted dirt weights close to 125 lbs per cubic foot. really wet dirts weight less due to fact the water is displacing the dirt and water weigh alot less than dirt itself. So wet dirt would be more like 115 lbs per cubic feet.
Edited 1/8/2006 2:12 pm by brownbagg
Here's another resorceful guy I haven't seen mentioned. He's been at it a while, too.Earth sheltered stuff... http://www.malcolmwells.com/ Hey, pocket doors can't come off the track if they're nailed open
that book you mention at the first of this post is $189 used on Amazon. They are proud of that book.. 2+3=7
You aren't really gonna make me reread this whole thing to remember which book are you? Can't imagine it's "Passive Annual Heat Storage" or "earth sheltered housing design". I heard awhile ago that PAHS was out of print, but turned out it was still available from Rocky Mountain Research Center, Lovins' institute.
Here you go http://www.rmrc.org/shopping.htm $49.95. Hmmm... ebook? No idea what that is. If it's not paper maybe they have a paper copy available there somewhere. Slightly confusing site. Might not have liked my browser.
I do have one book that got valuable, from Taunton of all places, out of print. But it's about chainsaws.
Regarding dirt, maybe that's why the engineer was somewhat vague. Or maybe I don't remember quite right. At any rate, from our 300psf live load is 75, leaving 225psf for the dirt and structure. From what you're saying, that's a little light for what I've done. I'd have to dig out the steel weight (and concrete) to know just how light. Was intending to have deeper dirt on the next place. Inspectors never check anyway, wouldn't notice if I used different bar joists. Thanks for the heads up. PAHS Designer/Builder- Bury it!
I notice in my library I have Underground houses by Robert L Roy isbn 0-8069-8856-8 and How to build your own underground home, a tab book by Ray G Scott isbn 0-8306-0001-9. 2+3=7
Those I don't have. Wasn't Rob Roy the guy killed when his house fell down on him? Unfinished, he went out to check on it during a storm.
Mine include "Homes in the Earth", mostly floor plans, and "The Underground House Book" from Gardenway that's helpful for anybody starting out. Even HUD got involved with "Constructing Earth Sheltered Housing with Concrete", prepared by the Portland Cement Assoc. which is also pretty good. Don't know if I got it from HUD or PCA.
For me, PAHS is the answer. Simple and can be very inexpensive. I even left out a significant part of the design and it still worked very well. You did read the excerpt? http://www.axwoodfarm.com/PAHS/UmbrellaHouse.html You won't see a house that looks anything like mine. But the concept works fine.PAHS Designer/Builder- Bury it!
Wasn't Rob Roy the guy killed when his house fell down on him?
maybe you're thinking of Ken Kern? - 'the Owner Built Home' -
quality information -
"there's enough for everyone"
You're probably right. Both names are familiar from the alt arch lists, but I haven't read either.PAHS Designer/Builder- Bury it!
"Ken was always experimenting with new and better ways of building. A stone mason at heart, he often pushed concrete and rock to its structural limits. He's gone now. He died when a concrete slip form dome house collapsed during a freak wind storm. He had just finished it and wanted to spend the first night in the new structure."
http://www.countryplans.com/jr_hist.htm
"knew I would have to explain the remark. Ken Kern wrote a series of popular books during the height of the back-to-the-land movement, circa 1975, starting with "The Owner-Built Home." In fact, he wrote so many books derived from that title that it began to seem like a joke to me.
How he died: He was sleeping alone in an experimental structure he built, (I believe it invovled PVC pipe, plastic and soil) and during a rainstorm it collapsed on him."
http://www.ibiblio.org/london/renewable-energy/mailarchives/greenbuilding/0415.html
I wasn't aware it was a concrete slip form dome.
'Nemo me impune lacesset'No one will provoke me with impunity
Edited 1/9/2006 1:12 pm ET by razzman
A couple people mentioned back a ways about buildings in this area that were built by piling up dirt, concreting over that, and then digging out the dirt...When I first moved out here, I had a similar plan. When I first came to this forum, I discussed it a time or three here...I was going to collect cutoffs from the local pallet and joist manufacturers..I was going to "brick-lay" up a dome with short pieces of lumber. Kind of like that round stairway that Rez keeps showing, made of short pieces brick-laid.Lay at least 3 layers of 6 mill plastic over that. Shingle lapped.Lay a rebar mesh over that, suspended with rebar chairs.And form the concrete over that. Mix by hand to almost no slump, and basically form the entire thing as if doing a sculpture, a bit at a time.Then go inside and use a grinder with chainsaw wheel to smooth out the inside face. Or simply form a new face inside with lath, and drywall. Or even leave it be, and paint or seal it...Labor intensive. Can be done a little at a time. Probably about as cheap as can be.
Rudeness is the weak man's imitation of strength. ~~ Eric Hoffer
Labor intensive.
Tired me out just thinking about it. <G>
You touched on a major point in alternative architecture, whether you account for owner/builder labor. Many don't. I do. Makes a huge difference in what you consider "cheap as can be". No right or wrong, just different.
Paolo Soleri, at Cosanti in Scottsdale, piled up dirt, sculpted to suit, and spread whatever thin shell concrete mix he used over it. Small spans, so probably minimal steel. Cured, then excavated and built a house under.
I find the idea of moving the dirt far preferable to your wood idea, but I've already undertaken, and amortized, the overhead of dirt-moving equipment. If it was shovel and wheelbarrow I probably wouldn't.
Forgot to mention that your idea would fit in well on the fc list. Probably somebody there who's already done something similar.
PAHS Designer/Builder- Bury it!
Edited 1/9/2006 10:27 am ET by VaTom
I notice in my library I have Underground houses by Robert L Roy isbn 0-8069-8856-8
I think that's the Rob Roy book I've got. I was NOT impressed! IIRC, he just has a couple inches of dirt on the roof. Just enough to grow grass on and look really scruffy. And the supporting structure is wood, not steel or concrete. I can remember thinking, "no way in He11!" I'd do one of his houses. Just begging for trouble.
Save your $$ and just check the book out from the library.
I did like Dan Chiras's book: The solar house: passive heating and cooling.
View Image
It isn't an 'undergound house' book so much as a energy efficiency book. Chiras is a little more of a tree hugger than I am, but he gives a nice overview of passive techniques and such.
An article on an earth sheltered house that was built a couple years back:
http://www.mwnews.net/html/ole_s_house.html
With a link somewhere in there to the company that built the structure.jt8
"The test is to recognize the mistake, admit it and correct it. To have tried to do something and failed is vastly better than to have tried to do nothing and succeeded."-- Dr. Dale Turner
What is the differance betwen gunnite and shotcrete? I thought that they were just a differant word for the same thing.
In gunite, the materials (dry mortar in an air suspension, and water) come down separate hoses to the nozzle, where they mix and are sprayed by the nozzleman. Nozzleman gets finer control over the mud, but also needs greater skill to control water, air, etc. http://www.reedpumps.com/gunop.htmIn shotcrete, the mixed mud (often Redi-Mix) is conveyed down the hose by hydraulic, piston, or peristaltic means to the nozzle where an air hose is attached which propels the mix at pressure. Less control, and results depend a lot on the quality of the mix... as close to a 0 slump as possible. Equip is less expensive, and can often be done via rentals (big air compressor and a typical concrete pump, plus a $200 nozzle).These are often referred to as dry process and wet process respectively. Similar, but more like fraternal twins than identical twins.
I don't see how the bottom line costs would be noticeably different.
My suggestion would be to total man hours and material for a Monolithic. It all adds up somewhere. Either there're too many hours, or the effective hourly rate is very high.
No offense, but I agreed the fc list in not at all understanding why Monolithics were so expensive. Not just compared to my cast-in-place (which nobody there was interested in) but to the thin shells they were doing, several commercially. A common assumption was that Monolithic took a large cut off the top, inflating the price. The money had to be going somewhere. My guess is that you were painted as a Monolithic guy, ie. uninteresting. The group really isn't cliqueish, or even particularly focused.
I regretted missing the Oregon conferences, which I understand were quite varied. There was even a presenter there from Spokane, Don Stephens, who designs extremely green houses, hates concrete. Cracked me up that he would bother to attend. His Annualized Geo Solar concept (AGS), which he claims far superior to PAHS, is currently under attack from some physicists who maintain he can't get enough heat into his dirt to do annual heating. I've never understood how it could work either, but there're a lot of things I don't understand... He recently posted that he's "too busy" to explain.
The Righmond failure was before your, and my, time. Let's see... http://www.ketchum.org/milo/Memoir7a.html 1970, 3 high school gyms in Richmond, hyperbolic paraboloids. Milo Ketchum was an interesting guy, investigated the failures. His son, Mark, keeps the web site which includes a lot of pictures of various thin shells. http://www.ketchum.org/shellpix.html Restaurant Los Manantiales, by Felix Candela, is a building I find inspiring.
and a bunch of practice to do well.
Exactly. One of the many reasons I'll stick to annual heat storage, which you clearly aren't doing, but maybe try dirt-forming. Bo Atkinson's done some amazing thin shell work http://www.midcoast.com/~bo/WeTiltDome.html
As you say, many ways to build a good house. PAHS Designer/Builder- Bury it!
>My suggestion would be to total man hours and material for a Monolithic. It all adds up somewhere. Either there're too many hours, or the effective hourly rate is very high. Well, I hope my listing of materials dispels the idea of them requiring extra materials, compared to what you describe. And the speed with which I've seen some built, with crews no different from what you described, dispels the idea of requiring too many hours. The ones I know some decent cost data for were very close in shell cost to what you described. I know some contractors scheduling two years out--maybe they have a demand that allows higher profit margin than some others are charging?>No offense, but I agreed the fc list in not at all understanding why Monolithics were so expensive. Not just compared to my cast-in-place (which nobody there was interested in) but to the thin shells they were doing, several commercially. A common assumption was that Monolithic took a large cut off the top, inflating the price. The money had to be going somewhere.Part of the confusion here is switching from your stuff to fc and back. With no fc costs detailed here, it's a bit hard to speculate. When we compare to other stuff shown in FHB, for example, we do pretty darn good on costs. And the comparison we did above showed no major differences with your stuff...I'm wondering what buildings were being compared to conclude "so expensive" and how comparable they really were.Here's what I observed about the fc work that I saw presented in OR. First, there seemed to be little interest in insulation. The buildings shown were typically uninsulated, which messes up comparisons on both cost and performance. There was absolutely no interest in what we use, which is 3" of sprayed polyurethane foam. That'll account for a bit of difference.The other thing I saw is that they didn't regard engineering in the same way. We're pretty manic about rebar patterns and placement, and achieve incredible strength and performance as a result. The examples of fc I saw discussed used seat-of-pants engineering (paying an engineer was an unnecessary expense, according to some), and had neither the rebar schedule nor the concrete thickness that I'm used to.I recall descriptions of a building in Mexico where the mud over the mesh was only an inch or two thick, and was a 1000# mix at that. It was described as "good enough" as long as it supported the weight of the worker. No load standards to meet. I was sitting next to my engineer, and I think he had heart palpitations. They also described the water-proofing process as "see where it leaks over the first year and patch it." Might work in Mexico's dry climate, but it wouldn't meet typical expectations of any client of mine. That could account for cost differences.Now, most of the builders I know gripe that we're over-engineered (one engineer told me he assumes that half the rebar will not be properly encased...such is his use of safety factors)--and absolutely are over-speced by fc standards--but I think we have a different expectation re resistance to wind events. And it's one reason the record has been so good for the air formed ones...we're observing a different engineering standard, if the descriptions I heard are accurate.So yeah, compared to most fc, we use more insulation, more concrete, more steel. While I fault Monolithic for a number of things, they shouldn't catch any blame for this, because first, I appreciate the high engineering standards, and second, we often build without any of their products, and so they don't necessarily factor into the cost picture at all.One other cost factor we catch that many others do not is travel...the cost of transporting equip to a site and housing a crew for 6 weeks or two months can add thousands to a project...not the life I'd like to lead, to be sure, and a not-insignificant cost.Winding this down, are the cost comparisons on comparable projects with comparable specs? If they are, they'll show similar material and labor requirements. If the specs or standards are different, then the cost comparisons won't be valid.
Part of the confusion here is switching from your stuff to fc and back.
Jim, the reason I did was that those guys have a better handle on labor costs for what you're talking about than I do. You haven't given any real man hour numbers. I'm totally ignorant there, but you keep asking about your bottom line. And I don't know of anybody who was building to your specs. What I am aware of is that there are guys who are doing the equivalent labor to a Monolithic that were very suspicious of Monolithic costs. As in, where does the money go? Clearly, I don't know.
One other cost factor we catch that many others do not is travel...the cost of transporting equip to a site and housing a crew for 6 weeks or two months can add thousands to a project...not the life I'd like to lead, to be sure, and a not-insignificant cost.
This was a large suspicion of mine. For instance, when you told me, way back when, that you had a couple of domes coming up here, it was clear that the crew was going to be imported. This is going to greatly raise the effective labor cost. Like I said, look at your material cost and the rest is labor- to the client. You can talk all you want about unskilled labor, but it's what the client pays that counts.
Then you say And the speed with which I've seen some built, with crews no different from what you described, dispels the idea of requiring too many hours. Well, it doesn't work both ways. What is your labor cost, after deducting material? How many man hours? There's an answer there. I don't have your information to figure it for you.
Cast-in-place about anybody can do. Hell, I read a how-to book, hired two guys who knew less than I did and we made this place. No imported labor. Looked into post-tensioning as a bar joist alternative and quickly rejected it. Primary reason for the high cost? Imported labor.
You're correct about a number of fcers, like MxSteve, who built an underground vault in W. Colorado. Zero engineering. He and I got into it over that. Unlike him, I have a very good feel for what I don't know (and consider it important), which is why I asked if you had specs for 300psi.
And the comparison we did above showed no major differences with your stuff...
Right, which didn't surprise me. I'm well aware that my costs are high for cast-in-place. Go above grade, remove the earthload, and I can get a metal formed (and bar joist) shell down to well under $15. That's where it realistically compares to your domes. You mention 6 wks (or more) of crew time, that's a lot of labor (and housing for it). Talk to somebody pouring subdivision basements, it's more like a couple of days. Bar joist roof is on in one day. Another to pour both slabs. What's that- 20% of your shell labor? The crews are smaller than your spray crews, and local.
As you've mentioned, earth loading raises the cost substantially. It's prepaying the heating/cooling costs- forever. Will it amortize? Depends on your numbers. Then there're guys like BB, and me, who think underground just "feels better". Just like dome folks.
If you recall, what I said was that I know of no alternative method (to mine) of going underground anywhere near as cheap. Still don't. Thin shell might, but not the Monolithic method.
Winding this down, are the cost comparisons on comparable projects with comparable specs?
Have I answered this adequately? I don't know cost for fc, or Monolithic, with earth loading. Above grade cast-in-place with a bar joist roof comes in substantially less than a dome. You want one? Me neither. Let's stop. Doesn't look like we're getting anywhere constructive, but I really would be interested if you come up with 300psi specs. Then we could do new comparisons, on underground, the subject of this thread. I'd love it if thin shell (one forming or another) was cheaper. And it might well be.PAHS Designer/Builder- Bury it!
Let's dispel a few things before we stop. Some things have been put out there that I don't wanna let stand as such.First, I'm not in a position to defend MDI's costs. And the people saying things about their costs aren't here to represent their own costs fairly. MDI has never built one of my designs, so I have no clue what they really charge for construction, except that my clients have always not chosen them when it's been bid out. Most I've used of theirs is an air form, but more often than not the builder chooses a different air form, too. Let's keep them out of this be/c they aren't here to explain their costs...hell, for all I know they have such a high demand that they can charge a premium. Good for them if so! Or maybe people questioning their costs aren't comparing comparable structures--no fc structure I've yet seen is a fair comparison, be/c the specs aren't nearly the same.I've given the hours for rebar, shotcrete, etc that we use as a budgeting guideline, and they're from an industry spreadsheet. I don't have a specific hrs or cost breakdown for a plain 2k house be/c I've never done one of those, sorry. My designs include a bunch of sculpted elements...dormers, cutouts, canopies...they take a bunch amt of time and screw up comparisons. They easily turn a couple or few week shell build into a coupla month fine homebuilding project. Not at all fair to compare that to a few poured walls. Our typical shell takes the time I mentioned be/c we're including elements that aren't covered with just metal forming and bar joists. To compare to what was described of the CIP structures, I'd have to cut a bunch of elements off my designs or find one done with no adornments, such as a storage dome, and in leiu of that, I make some guesses. The figures I gave you would be enough to calc a simple shell cost and timeframe.>Go above grade, remove the earthload, and I can get a metal formed (and bar joist) shell down to well under $15. That's where it realistically compares to your domes.And it's rated for 200+ mph winds? And 2500 psf loads? And insulated? And as low in energy loads as we achieve? Bull. We aren't gonna compare an above ground concrete box to a house with sculpted eyebrows, canopies, insets, the best insulation, etc. and call it realistic.Geez, our stuff covers a huge range, and can't fairly be lumped under a single "domes". There are stadiums, intricately sculpted luxury houses, survivalist structures, storage sheds, and much more. If we're talking about a shell for storage, which is the closest thing to the CIP box described, there'll be a different set of economics than for the houses I design. My houses do not realistically compare to metal-formed, bar joist shells...that's bordering on insulting. If you want to compare to your $15/sf, we'll toss together one with no insulation and a reusable air form...I don't have those costs be/c that's not what I do, but there's no reason to think that with much less concrete than CIP would use, it wouldn't be the same or lower cost. The only reason I don't have hard numbers for it is that there's not been a demand for that aesthetic.>The crews are smaller than your spray crewsYou keep saying that, but it's not true. My house had a crew of three, often two, and sometimes four. The one's under construction now have crews of 4 each. Some of them use local labor and some don't.And if you're gonna hit on labor not being local and high costs and specialized labor despite all I say to the contrary, I'll focus on the many people who are building these completely on their own with crews of two and all local labor and equipment. I haven't focused on that here be/c that's not my business model...my designs are for finely-built and luxury houses, and I focus on the few contractors doing that consistently. But people are building these with the same home-grown approach you used, and achieving fine results without any travel or high-value labor, so let's keep that whole travel issue in perspective. There are only a few traveling crews, and they tend to focus on the most elite houses and largest stadiums, where experience and quality and detailing are the primary considerations.>As you've mentioned, earth loading raises the cost substantiallyDid I say "substantially"? I've looked and couldn't find it. I just said it's an _additional_ cost to move the dirt around with little commensurate benefit for us. I'm running $40-$80/m for heating or cooling in season for 6000+ sf. I don't have a whole lot to gain with earth loading. Now if it were required, we could easily do it. Simply do the shell without the foam...everything else the same as PAHS...and note that I said earlier that I liked the PAHS concept...just haven't had the call for it.>Thin shell might, but not the Monolithic method.By thin shell, do you mean fc? Be/c the air formed method IS thin shell. Inflate, rebar, spray. Less material, same labor. What's the big deal? There's no reason to think they wouldn't be comparable, with the dome providing unequalled strength.>but I really would be interested if you come up with 300psi specs.I assume you mean 300 psf...that's what was in earlier posts.A typical hemisphere, as I've mentioned before, will use about 2# of rebar/ssf and 4" of concrete. I was actually overly generous, be/c it'd use 4" of concrete for just the first 8' or so and taper off to 2.5" overhead.I did reach my engineer today. To merely satisfy a 300 psf spec, we would have to REDUCE the concrete and steel substantially. The building described in the prior paragraph, with #3 and #4 bars about every 12" and the concrete thicknesses listed, would, with no further modification, provide for well over 2,500 psf with an engineering safety factor of 3. The limiting number is the 2.5" concrete up top. Wanna make it hold double? Increase the rebar one size and add an inch of concrete.And I have the decimal places right...2500 psf...he said the numbers calc to over 5300 psf, but he cut it in half to be conservative.Tom, I'm worried that the tone of this is too harsh, and I don't mean it to be, but I've spent enough time editing it. I don't wanna sound grumpy, but I also don't want misinformation out there. We have enough challenges when the information is _accurate_...
Great pix. Yours?
first three are my daughter's from 2004 - last one I pulled off the net - she spent a month traveling in eastern europe and turkey before school in england -
"there's enough for everyone"
Natural light usually is the big issue. You either need lightwells, or you need space for "sun" lighting (the full spectrum lighting is usually hotter--temperature--and needs more space to be comfortably habitable.
The next big hurdle is in AHJs 'letting' you do this--egress requirements will make it less of an "underground" house at every turn.
The various access requirements equal penetrations in the envelope, and every penetration is a potential leak in the proposed u/g house. And everyone, from SOs to the lendor, all want a different break in your w/p skin of the structure.
This is where "earth sheltering" (which may be the best search term to use) can help. At least at the single-family house sort of level. For a submerged arcology, that's a different sort of thing altogether. (I'd be tempted to build/design that rather like a submarine, with an inner and an outer wall . . . )
Nuke,
The opal miners in northern New South Wales and South Australia excavate below ground to find their gem stone lodes. They convert their diggings into spacious living quarters when they are satisfied that they have exhausted the source of colour. The big advantage for them is the insulation from the fierce heat of those low humidity areas. Maintenance is not a problem for them either.
You may wish to google Coober Pedy for more info.
Lapun