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General => Owner-Builder Projects => Topic started by: thefinchnest on July 09, 2011, 11:38:37 PM

Title: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 09, 2011, 11:38:37 PM
Hello all!
We have been reading here for a while and thoroughly enjoyed and benefited from all the knowledge and experience on the forum. We are a family of four living in north central Texas, and feel like it is time to set to work on our low impact, high efficiency home.

We have been researching underground/earth sheltered construction upwards of a year, and are leaning heavily towards a variation of Mike Oehler's designs (similar to the Troglodyte cabin). My wife and I are by no means experts on earth sheltered building, so we would like to ask for a lot of input from those of you who have experience here. I have some construction experience and am relatively handy in wood and metalworking, but building a house to properly shed water with a structure made of wild oak from the woodlot will be brand new to me!

So, the purpose of this post is to get input from folks here on my current (shadow of a) plan, 'cause I'm not too proud to admit I need a lot of help! Smiley I've attached some photos my sweet wife took of me standing in our prospective site (for scale, I'm six feet tall). It's a dry pond excavated into a gradual hill with the dirt removed use to build the downhill dam (which is toward the north, which is behind me in most of the pictures). It poses a couple of challenges that I think can be overcome, but I need folks with more brains than me to weigh in... So, please see attachments!

(https://i1142.photobucket.com/albums/n607/finchamplification/1.jpg)
(https://i1142.photobucket.com/albums/n607/finchamplification/2.jpg)

As you can see, it's relatively spacious, about 65'x40', depending on how you measure it. Excavating further is not too big a deal, and I figure will have to happen since it's a typical teardrop/ice cream cone shape. We're aiming for something just over 2000 sq. ft. At this point, my plan is to have the front door at the north (where the dam is) under a sizable round gable with plenty of windows, and the back door/uphill patio at the south, where you see a depression/runoff channel already exists. This depression is where my wife is taking the second picture from.

(https://i1142.photobucket.com/albums/n607/finchamplification/3.jpg)

The side toward the west (shown here) is a slight downhill from the plot, and shouldn't pose any problems. I'd like to bring in plenty of light with dormers or a medium gable.

(https://i1142.photobucket.com/albums/n607/finchamplification/4.jpg)

Behind me is the east side, and one of two potential issues I see. It is a gradual uphill from the plot, with minor runoff potential. Problem is, this is in addition to the uphill southerly slope, which bears significant (but not insurmountable) runoff potential. At this point, my best solution is to extend the uphill patio all the way from the southwest corner around the east side of the house to the very northeast corner, effectively making half the circumference of the house an uphill patio. Not bad, in my thought, since when we were planning a conventional house my wife asked me very sweetly for a BIG wraparound porch. Smiley I've just never seen it done this way, so I'm trepidatious.

The second issue I see is the south end. As I said, the pond is teardrop shaped, and comes to a sharp point that is somewhat deeply recessed (approx. 4 feet is my guess sitting here) beneath the pasture to the south. Problem is, this point is maybe 30 feet south of where I expect the south face of the house to be. Now, here is where I get pretty lost, no doubt... I have thought of backfilling it and making a conventional uphill patio closer to the house. I have also thought of trying to incorporate the entire area into the uphill patio, which would be doable, while requiring some clever runoff control (large culvert running under the house or east patio, maybe?) and making the patio QUITE large on the south end. I have even though of excavating a deep little fish pond in it and dealing with excess runoff via overflow pipes similar to the previous idea. There are several other ponds on the land where similar systems work like a charm.

I have a few (more brief) questions about my construction plans, and will post drawings later, but for now I'd mainly ask for input on this possible site. Is the groundwater workable? There are a couple of single incline grades available that I can use if I have to, so fire away. But we really like this spot for a lot of other reasons, so it'd be nice to make it work. I'm open to suggestions!

Aaron, for the fam!



P.S.: Once we break ground, I plan to document every step of the way, mistakes and successes, here on the board, and hopefully a blog, just in case someone else can learn from my experience. I'd like to give back as much as I can, since I know I'm asking a lot of input here. Thanks for reading!

(https://i1142.photobucket.com/albums/n607/finchamplification/5.jpg)

If anyone cares, this thread is cross posted at: http://www.permies.com/bb/index.php?topic=9150.0
Title: Re: Our Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 09, 2011, 11:51:48 PM
Hmmm, I apologize, I can't find a button to edit the thread title to include dimensions...  ???
Title: Re: Our Underground House - Stage 1, with Pics!
Post by: glenn kangiser on July 10, 2011, 12:00:07 AM
Just retype the title to edit it, Aaron, and welcome to the forum.  Additional postings will come up titled as the current title If I recall correctly.

...and  welcome to the forum.  Looks like an interesting project to me.

I see a power pole.  No neighbors or codes to give you problems? [noidea'

That should be the modify button on the first posting. Don did have some functions limited on new members but I don't recall that being one of them.
Title: Re: Our Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 10, 2011, 12:31:40 AM
Mr. Kangiser,
Thanks, good to be here. Very keen of you to notice the pole! Thankfully, there's no permits, inspections, or codes where I'm at. Neighbors are a couple hundred yards away and don't bother us.

What do you think of the potential site?

Aaron
Title: Re: Our Underground House - Stage 1, with Pics!
Post by: glenn kangiser on July 10, 2011, 12:48:55 AM
I think it looks good.  It is a bit hard for me to tell about drainage, slopes etc.  Seems they never show up on pix as steep as they seem when standing there.  I would be aware of being too close to potential runoff areas.

Have you had the property long enough to evaluate soil types, building and digging potential, etc.  What is available on the land as far as sand, gravel, clay, rocks, boulders...natural resources?  All could be figured as potential building materials depending on what is there.

If there is a potential problem with drainage a bit of a mound could be used also.  I always recommend French Drains draining to daylight downhill now.  I am in what could be considered a relatively dry area, yet winter rains and gophers rerouting drainage have caused some problems.  Ten years almost is still a significant proof of concept to me.  A lot of living has gone on there.  :)

Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 10, 2011, 08:50:10 AM
Yes, sir. I agree! We hope to engineer the same longevity here. :)

We have been here for a while, and the soil, while not great for a garden, looks great for plenty of cob. We have all the medium to fine sand plus red clay we could want. It's mixed in with bentonite here and there, but not bad. That's mostly deeper down. The bottom of the pond is red clay (under the first inch of eroded sand). I'm planning to do straw bale outer walls (it stays around 100f, 80%rh here in the summer) stuccoed with cob, and several interior walls of cob, as well as an earthen floor. I haven't decided whether to cement stabilize any of that yet, given the humidity here and the issues many have noted with portland's water retention. I'm definitely hoping to use mostly native materials, other than decking, straw bales, and lime for plaster. I'm hoping to keep total expenses under $10,000, since that's basically as much as we can spend. I think it's very doable, since the cob and round oak are available here.

I'd rather not do much of a mound, so I'll probably either backfill the south end or put in a large drainage system to a downhill tank for the garden. :) It's interesting building in the south, since my main comfort concern is heat, not cold. Most underground construction resources I have seen were written with a much colder climate in mind, so I'm trying to draw out as much of that geothermal cooling as I can!  :)

Thanks again!
Aaron
Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: glenn kangiser on July 10, 2011, 09:49:39 AM
Sounds like a great cob mix.  Plenty of straw in the mix will reinforce it into a highly earthquake resistant structure.

Thick earthen walls also work to keep out summer heat providing a thermal flywheel effect, though the temperature will stabilize to somewhere between the cool of the earth and the heat of the day.  Strawbale insulation will help to keep more of the cool inside and prevent penetration of the outer heat.

I am more of the opinion that lime is a better stabilizing agent than Portland cement now.  Hydraulic lime seems to be the best type if available.
Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 10, 2011, 12:41:03 PM
Great! I've heard good things about lime, and love what Simon Dale has done with lime plaster, but there's not a lot of information on it out there anymore. I'll see if I can find a source for hydraulic lime.

Your point is exactly why I'm considering straw bale walls. If I were to depend solely on thermal inertia, I figure the house would stay at least 90 in the summer. My hope is that by insulating vertical walls, but not the floor (moisture barrier aside), I can pull the summer temperature down to comfortable levels. Even if that causes it to be chilly in the winter, it will be fine. Our winters are pretty mild, and the lowest it EVER gets here is about 15 degrees. If the house stayed 45 or 50, solar gain would pull it up nicely.

Thankfully, we don't have to worry about earthquakes here, but tornadoes are a big concern. Shouldn't be a problem with a heavy, half buried house, made of logs instead of softwood sticks. :) Throw on some shutters and call it good! d*

Aaron
Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: glenn kangiser on July 11, 2011, 09:22:36 PM
Sounds like it will be fun, Aaron.  :)
Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: thefinchnest on July 15, 2011, 06:37:40 PM
Howdy again!

I came up with a few drawings that may help illustrate the drainage situation I have here.

(https://i1142.photobucket.com/albums/n607/finchamplification/satellitefootprint.jpg)
The low area.

(https://i1142.photobucket.com/albums/n607/finchamplification/satelliteelevationanddrainage.jpg)
Existing slopes and runoff patterns.

(https://i1142.photobucket.com/albums/n607/finchamplification/satellitefootprint2.jpg)
My current idea for the house footprint, showing uphill patio wrapping around east and south sides. If the roof is confusing, maybe the next pic will help.

(https://i1142.photobucket.com/albums/n607/finchamplification/satellitefootprintdrainage2.jpg)
More detail on the roof, with drainage patterns.

I'm particularly curious to see what folks think of the wraparound uphil patio, but I suppose the main concern for now is drainage. Any thoughts, anyone?

Thanks!
Aaron

Title: Re: Our 40'x55' Underground House - Stage 1, with Pics!
Post by: glenn kangiser on July 17, 2011, 11:27:29 PM
Seems you are trying to put the house where the water collects.  Wouldn't you want to get it on a hill and use your depression area for a place for runoff to collect?  Been a while since I have had time to look but thought I would ask.