Earth Sheltered Home Design

[LQB]

Ever since watching the Lord of Rings trilogy and currently, The Hobbit, I've always craved living in a "hobbit house" (earth bermed), with lots of curves and roundness, instead of sharp corners and angled pitched roofing.
Came across a website/blog by a guy who built a hobbit house for under $5000 mostly by himself, except for help lifting some of heavy rafters.
His home is so adorable and cozy; i just love it!
He provides more images of his home in different phases of construction, with brief instructions on building his home.
http://www.simondale.net/hobbit.htm

There are some issues that you need to be aware of with this. The amount of earth cover over the top is thin (due to structural limits) so your insulation must be achieved from the interior. Drainage issues can be big depending on the construction materials used. If layers of wood planking are used, dry rot is inevitable.

It is charming though. :)

 

[Skyfarmr]

There are some issues that you need to be aware of with this. The amount of earth cover over the top is thin (due to structural limits) so your insulation must be achieved from the interior. Drainage issues can be big depending on the construction materials used. If layers of wood planking are used, dry rot is inevitable.

It is charming though. :)

Good point! however, when studying the diagram, it appears that there is a membrane incorporated between straw insulation and the soil which lies above it, and the pitch would seem to provide good drainage... but then there might be a concern over erosion of your roof "insulation"?

Still, it's quite impressive and ambitious for a novice builder.

 

[LQB]

There are some issues that you need to be aware of with this. The amount of earth cover over the top is thin (due to structural limits) so your insulation must be achieved from the interior. Drainage issues can be big depending on the construction materials used. If layers of wood planking are used, dry rot is inevitable.

It is charming though. :)

Good point! however, when studying the diagram, it appears that there is a membrane incorporated between straw insulation and the soil which lies above it, and the pitch would seem to provide good drainage... but then there might be a concern over erosion of your roof "insulation"?

Still, it's quite impressive and ambitious for a novice builder.

If that pitch is near to scale, I don't see how that would stand up to heavy downpours. That membrane won't last - tiny pin hole leaks (from animals, birds, etc) will allow moisture penetration, and what's below it will eventually rot.

The benefit of the earth-berm can easily be lost if the roof is not well-insulated. IOW cold in the winter and very hot in the summer.

 

[ziggystarlust]

We bought the book and CD set from this company before we ended up finding a great deal on a cabin. They show some really great design ideas. I still dream of one day building one. He has some cool greenhouse designs as well. Its a good amount of info for cheap and its simple to understand.

Here is a ladies blog I came across and although it not underground and is cob it is still a really fun,creative, and cheap structure. Her artwork on the walls is why I am sharing the link.
http://www.cobdreams.blogspot.co.uk/

My plan has been to start small, making dog houses and chicken huts agianst the side of the hill with earth bags and then trying our hand at a shelter mabey at some point.

Thanx for that info. It seems from other comments on the site the book is very good. And as for the cob-designed houses, it seems to take one away from the linear 90 degree angle world into something more fluid and creative-providing that you have the clay necessary for such architectual exploration.


Edit=Quote :)

 

[Voyageur]

I started a new thread here for those that expressed interest in comments I made in the Wooly Pig thread (http://cassiopaea.org/forum/index.php/topic,30963.msg408256.html#msg408256) - so as not to hijack that thread.

The primary goals in underground (or earth sheltered) homes are:
1) use of the earth heat sink to blunt temperature extremes much like a cave does
2) reduce exterior maintenance to zero
3) extreme stability and life cycle
4) blend with the local terrain and minimize impact

In my own case, I added another important (to me) design criteria - make use of existing infrastructure (grid power, etc) but design in backup systems so that the abode remains comfortable in the absence of high tech machinery and the power to run them.

Well done LQB, checked the photos also and was impressed with the engineering thoughts that went into your project home. There are a few similar ones around here that i know of, but not to that design build (they are about 25 years old). Another fellow up the highway has what appears to be a roughly 10x10 above ground structure; the entrance, and the house is completely underground, and am not sure if he has systems for natural light - does not appear so.

Was curious if you considered, or if ICF type Reddiforms _http://reddiform.com/why-reddiform-concrete-forms might be a good alternative; especial where ground frost is deep, would be a good idea? This would be commensurate with engineered strength of course (think they or another manufacturer sell wider forms).

Anyway, Kwel! :)

This one is our home, (All the construction in 7 min. http://www.youtube.com/watch?v=bNHQK-R5Fqw ) the big dome is dobble bag, in the front, until half high, thick of this wall +'n - 1 meter.. the rest of the wall's dome are 50 cm, it's already cool..
is the only one I've put on line .. (for now)

Very original freesurfer, also

 

[LQB]

Was curious if you considered, or if ICF type Reddiforms _http://reddiform.com/why-reddiform-concrete-forms might be a good alternative; especial where ground frost is deep, would be a good idea? This would be commensurate with engineered strength of course (think they or another manufacturer sell wider forms).

I looked at ICF years ago - I liked it but discarded it for this application because:

1) It didn't seem structurally sound enough for full burial
2) Insulation against the ground was not the goal - using the ground heat sink is (like a cave)
3) ICF cost (at the time) was too high

In other thermal environments or above ground applications, ICF is a good way to go.

 

[freesurfer]

good evening guys..
I will do schort.. I'm tired.. but to answer to some one..
to thing, read and write in english is still gymnastics for me, but anyway.. I like, (you imagine) this thread.. (and definitively languages) ;)

Citation de: Horseofadifferentcolor le avril 10, 2013, 04:56:13 am
My plan has been to start small, making dog houses and chicken huts agianst the side of the hill with earth bags and then trying our hand at a shelter mabey at some point.

Horseofadifferentcolor, that is an excellent approach - build storage sheds, out-buildings, animal shelters before starting your home. You will learn a lot and minimize the mistakes and impact on your own abode. Much like freesurfer says above. While building these other structures, it will give you plenty of time to think and meditate on what you want in your own home - lots of ideas will come to you for processing and consideration.

Right.. a lot of ideas and mistakes.. I think the best is making something to the human scale, not to small.

my prototype, was in 2009 a little bit for fun and change.. I thought.
I upload yesterday an other small and quick old slide show .. that you will find in the same link .. (second video)
the mistakes was:
1: not enough drainage and direct contact with the house (even having a "liner")... the best with experience is a vertical filter of graviel with (of course something making "liner" again the house and) some geotextil between the ground and the graviel.. since the drain to the floor ( and a canal on top of that is the must) that cut the capillarity, and let breathe.
2: square windows or doors.. the best is definitively arch (vault) or round form ( (and more solid)
3 use just natural material (specially in ecuador.. where we have nice rain season) the prototype was plastering outside just with lime-sand and soil, ( ands traw) using for mix the juice of the prickly pear (macerated, is a good glue and waterproof, but not enough ) and red mineral pigment on top. The balls are li-sa-so also, painted with pure hidro-lime and pigment (but, if you don't find de lime ok Marakech forget) after we put just lineseed-oil and it's ok, just renews the process two time in the year..
4 no windows opening in the bed-dome, just natural ventilation.. not enough flow of air. But sleeping under a starry sky is just .. incredible

So not to be to much "ecolo".. to be realist! We change the top and cover with a synthetic layer and we save the "test dome"

Hi Freesurfer,

Wow! I loved watching the video - it has really inspired me, thank you for sharing!! .. and I wondered if I could send you the design when I have finished it for your advice/guidance? (before I start building it!)

first.. thank's and will be a pleasure of helping you ;)

Wow! Great video freesurfer! That was fun watching it go up that way. And very nice looking finish - and, I'm sure, very comfortable inside.

Wow! This is a fantastic video freesurfer, and congrats for your finished home ! Looks so... natural...

first thank's too.. but is not very finished, just 95 % still need 5 %.. connect electricity and "potable water", change some wooden doors ( all the wood wasn't dry ) I finished remake an other door just before, with my super assistance of 5 years old.. and wait the end of this "last" contract for cash$$$ :/ and time.. don't believe that is an inexpensive house.. I spend +'n - 52k and 9 month (I don't count me in this price, 7k for the small one )and need still the barriers of the balconies and one external staircase..
I work on.. evening .. saturdays .. when I can .. but no stress for the home... the main thing is that my family (6 pers) can eat every days..
but indeed, look very crazy and confortable inside.. soon I will show you all the "inslide job"

If you are going to bury a structure to gain the benefits of the earth heat sink, the home will be sealed from the outside air, and it is important to control air flow with the outside for fresh air (in) and exhaust air (out). Whether or not you use a fan (powered) system, you need to plan intake and exhaust ports into the structure. You will want strict control of this via dampers or gate valves for extremes of temp/humidity (cool mornings in the summer and warm afternoons in the winter). A vent fan (like a vortex fan in pvc pipe) will exchange the air quickly. You can do it passively (over a longer period) by extending the exhaust vent pipe well above (in height) the intake so that the small pressure difference drives the air flow from in to out.

You can consider a filter on the input to stop particulates in the air. A fan works much better and can be easily and cheaply powered by a 12V battery. Removing the filter will allow the passive approach to work as a backup so long as you get the exhaust pipe outlet well above the intake (or have the option to do so).

you know something about provencal or canadian well? Can to be very interesting with an underground house. ( and with an Ice age too )
make your research, all the links I have are in french (puits provençale) .. nice thing..

well, not very short.. (for me)
I hope everything is comprehensible..

good night everyone. r

 

[Gary]

"good evening guys..
I will do schort.. I'm tired.. but to answer to some one..
to thing, read and write in english is still gymnastics for me, but anyway.. I like, (you imagine) this thread.. (and definitively languages) ;)"


Freesurfer, thank you for putting the effort in to share, especially when english is not your first language. I think you express yourself very well :)

"my prototype, was in 2009 a little bit for fun and change.. I thought.
I upload yesterday an other small and quick old slide show .. that you will find in the same link .. (second video)"

I can only see the first video, not the second?

 

[MK Scarlett]

"good evening guys..
I will do schort.. I'm tired.. but to answer to some one..
to thing, read and write in english is still gymnastics for me, but anyway.. I like, (you imagine) this thread.. (and definitively languages) ;)"

[...] I can only see the first video, not the second?

Here is the second video:
http://www.youtube.com/watch?v=-yAk9W8P4-A
The two videos are on this link http://www.youtube.com/channel/UCh55ckUtBBmCD7yU0ABqFCQ?feature=watch

 

[Gary]

Many thanks, MK Scarlett :)

 

[freesurfer]

Many thanks, MK Scarlett

thank you MK Scarlett.. one more time ;)

especially when english is not your first language. I think you express yourself very well

thank you, ;) but this one was really funny

(but, if you don't find de lime ok Marakech forget)

I wanted to say.. if you don't find THE lime OF Marrakesh, forget!
the lime of Marrakesh contain marble "dust" and is waterproof.. for to be more clear.
see tadelakt for more info http://www.google.com/search?q=tadelakt+bath&safe=active&client=safari&rls=en&source=lnms&tbm=isch&sa=X&ei=mcxoUYvkGYXe8ATBrYHoAw&ved=0CAoQ_AUoAQ&biw=1273&bih=627
greetings

 

[Voyageur]

[quote author=LQB]
I looked at ICF years ago - I liked it but discarded it for this application because:

1) It didn't seem structurally sound enough for full burial
2) Insulation against the ground was not the goal - using the ground heat sink is (like a cave)
3) ICF cost (at the time) was too high

In other thermal environments or above ground applications, ICF is a good way to go.
[/quote]

Yes, totally get what you are saying, i would have to consider the frost implications for our area.

Found a couple of earth shelter sites; building examples, along with one that used icf. Yet the logic of what you have said to capture true heat sink would negate its use.

This thread is interesting as it has lead to look into some of these things. Here is an engineer answering peoples questions about icf and he is not a big fan necessarily, he says: "The Insulated concrete forms (ICF's) are very common, with several dozen manufacturers, but they are not very energy efficient."

_http://www.earthsheltered.org/new-hampshire-icf-earth-shelter

Dr. Nabil Taha has over 27 years of structural engineering experience. Prior to opening his own engineering firm in Oregon in 1997, he was a Professor of Engineering at Northern Montana State University and at Oregon Institute of Technology. He has structural expertise in a wide range of building systems and can answer questions related to virtually any common building method. His focus is on green design and he is always willing to trying something new. Dr. Taha is dedicated to future sustainability through innovation; he creates solutions for beautiful sustainable and safe structures by melding old and new technologies. He loves a good challenge. He is Licensed in twenty three states and can design buildings and/or consult to assist with structural permitting in these states as well as internationally. As a prior College Professor, Dr. Taha is a teacher at heart. He loves to share his knowledge and offers educational seminars and trainings for the do-it-yourselfers and professionals alike. Dr. Taha's goal is to continue to grow and provide knowledge and services for those trying to make their dream project a reality. No project is too big or too small. For information about Dr. Nabil Taha and his engineering firm see _www.structure1.com

This was also a good site for earth sheltered homes with a few interesting ideas. _http://www.earthshelteredhome.com/

This (the fist half) is an interesting ES house design, wish there was further footage.

_http://vimeo.com/6876609#

 

[LQB]

This was also a good site for earth sheltered homes with a few interesting ideas. _http://www.earthshelteredhome.com/

Yes, this one of the contractors that wants to put a dome roof on the structure (for the reasons I mentioned above). From the outside, they look like one continuous structure, but they are actually made up of connected boxes. They require huge holes in the ground and/or massive landscaping. Drainage becomes an issue that just adds more to the cost.

 

[monotonic]

I just had a funny idea. You know how you always wash your hands in the bathroom and then grab the doorknob? Is the doorknob clean? What about when you're holding a bunch of things but need to open a door?

Why not just make doors so we open them with our feet? Then there's no more problems with greasy doorknobs or trying to open a door with grimy hands and it's easier to multitask. For one thing if you're grilling and you've got raw meat on your hands, you don't have to get it all over the doorknob.

 

[Luis Miguel]

This post is great, thanks for all the great ideas and information. Awesome job with the houses freesurfer! :) Thanks for the videos. I have been studying about this kind of constructions and self-sustainability for some months. I feel more inclined to this kind of construction: earthships.com. Supposedly, one house can be built in about 8 weeks, of course, this depends on the available hands.

One of the focus of this houses is thermo-mass, the materials used for construction are ideal for normal to extreme weathers, and most of the materials are free. You can find this kind of buildings in South America, New Mexico, Alaska, etc. They call this project the Global Model, because it can be built and is suitable for all kind of weather. The main material are tires, earth and mud. The creator said that if someone gave him 300,000 dollars to create a perfect thermomass insulation material, we would have come up with tires. And the process is similar to the earth bags, you fill them up with earth, pile them up - depending on the shape of the house -, and the structure can be covered with mud (a "recipe" that you can find in the books), and if you want, you can add a cement layer at the end or just stay with the mud (similar to adobe). It depends of your needs and preferences.

It has facade similar to a greenhouse, that works as a 'buffer' between the exterior weather and the inside of the house and provides lots of light from the sun. And also you can have plants in there. The ceiling is resolved with wood beams, wood panels, insulation and mud or cement, or with wireframe, insulation and cement. It has a north facing slope, that not only helps to obtain water from the rain and storage it, but it melts the snow pretty fast. Also, they add some tubes in the lower part of the house that come from outside and some openings in the ceiling of the 'buffer' to have a ventilation system similar to a convection engine. So if the weather is too hot, you open the 'vents' and that's all. The idea of this Global Model is to provide all the necessities in one place, including water and energy. Now, I'm thinking that if you want lower prices you can modify, adjust or simply eliminate some of the systems or materials (for example, they use eolian and solar energy for the power that is very expensive)

The inner walls and details can be done with mud or cement, and they use cans or bottles to support the structure. Also, the building is buried with earth surrounding the outer walls and they add a sheet of pink insulator. In very very cold weather they also add insulation in the floor.

Here are a couple of examples:

Global Model:
youtube.com/watch?v=N2so9hyNWxc

Simple Survival Model:
youtube.com/watch?v=wTqSpx0Vgv4

And a intro to this kind of contruction:
youtube.com/watch?v=L9jdIm7grCY

The construction prices can vary from very affordable to very expensive, again, depending of what you want and need. A lot of things can be modified or customized.

I'm still reading about this. I'll be sharing the info here :).