Stockton Earth Home Project

An earth home is no more a cave, than a penthouse is an attic.

Mike Oehler method & other methods

 There was a question posted in the guestbook about my opinions regarding the building method that Mike Oehler uses in his book.  I had listed the book in my references page, because I wanted to provide a good cross section of building methods for earth homes.  Mike's is a less expensive, and less environmental impact than some other methods.

I liked the book.  I think it shows what can be done with a small budget and a willingness to put in some labor.  It's a worthwhile building method.  We chose a different method for a number of reasons.  I'll list them in no particular order of importance:

  1. We live in an area where the termites are very active and they are nearly unstoppable here.  We want to build a home that will be lower maintenance, especially after we retire.  If we didn't do something a little more permanent, we'd be doing a lot of labor on the house just to keep it livable well into our retirement.  So we chose the Terra-Dome method instead.
  2. We had considered the Earthwood Building Method (Robert L. Roy writes about this in a number of books, also listed in my references page).  This method would work for us because of the concrete foundation, and keeping the first course of cordwood a foot above the ground.  The reason we ended up not going with this method is because of how labor intensive it would have been for us.
  3. We live in tornado alley.  High winds frequent this area.  We wanted a roof that would hold up to some wind pressure.  The method we chose does that.
  4. We had considered Davis Caves, but Rachel and I were attracted to the semi-domed ceilings in the Terra-Dome buildings.
  5. We have had a fire or two in our immediate area in the last few years.  We had one first that I'm not sure how far it traveled north, but it traveled east 8 miles.  If it had only traveled about half a mile further north in the area we were are located, it would've gotten our property.  So we were considering options that would be less vulnerable to fire.
  6. With the humidity we get in our area, we just didn't think that straw bale would be a way to go.  We could be wrong about that, but it was just our opinion at the time we were looking at the options, and we didn't choose straw bale.  This is also the reason we felt that a wooden structure such as what  Mike Oehler has in his book.

As I made this list, I sort of covered other options that we'd looked at as well, because there wasn't much of a reason we didn't choose the Oehler method.  It was mainly a process of elimination to arrive at the method we chose.  Apart from the issues of wind, fire, termites and rot (due to humidity), the Oehler method would have been great.  In other areas of the country, especially in a drier area, it would've gotten greater consideration.

Rain Water Collection

We had a question about rain water collection.  We do plan for this, but with the amount of work I have, I feel that at this time, I just want to get the house built.  We are putting in a french drain system all around the house, as well as drains that will allow water off the roof.  I expect that later on, we will add some sort of storage, a cistern or something of that nature, to collect the water from the drains.

I would go ahead and put in a cistern or two, but that costs money and we're on a budget right now.  I just want to get the house livable so we can move in.  We have a lot of projects to complete, but I do hope to add the rain water storage.  I'm also hoping to eventually put in some PV (photo-voltaic) panels to supplement our electricity, as well as a wind turbine or two.  These are currently expensive items, so they're going to wait as well.  We do want them though.  That time we were without electricity wasn't fun.  I want the ability to at least power the water well pump, the freezer and refrigerator if we have an outage again.

I got off track a little bit on rain water collection, but the point is that this is something we want to do.  We will do it, but like many other goals, it's going to have to wait because of lack of time and money.  We hope to eventually have rain water collection.  This water can be used on the garden and other non-drinkable uses.

 

Water-Proofing

What about water-proofing?  The answer is complicated.  It's not a product that I can recommend, which is usually what people want to know when they ask.  It doesn't work that way.  The reality is that there's no such thing as water-proofing (as far as building materials are concerned).  There's just no such thing.  Anyone that tells you otherwise are either lying to you, or they don't know what they're talking about.  You can have water-resistent products, but nothing is water proof.

The idea of water-proofing isn't something that you can get a product as a solution for.  The products help, but ultimately, water-proofing is a technique.  The goal is to get water away from areas that you don't want it to stay.  In essence, the only water-proof system is one that doesn't get wet.

So here's how it works.  It's simple.  Think about it.  Water runs downhill.  It's gravity.

Water is an unstoppable force.  Therefore, the best water-proofing technique in building a house, is to provide a path for the water to go, to get it away from where you don't want it to be.  That's it.

We are employing products such as Ecoline-R and Ecoline-T, as well as Paraseal, as a means of eliminating moisture penetration long enough for the moisture to find the path we've provided for it to flow away.  This works and many people building earth homes and been successful with this technique, using a number of different products.  It's not the product that is as important as the path you provide, and making sure that there aren't going to be any way for the water to backup due to blockages.

So in summary, any places, especially but not just the roof, that you want to waterproof, use common sense and be aware of slope.  Anywhere that you can provide some means for slope so that water will flow away rather than collect, is the way to go.

Heating and Air?

What kind of heating and air system do we need?  That's what people ask.  I can't give you a definitive answer.  It's going to vary depending upon the design of the home.  However, one thing I do want to emphasize, is to not trust what the "trained" HVAC (heating ventilation and air conditioning) professionals tell you.  They don't know what they think they know, in most cases, when it comes to this type of home.  They just don't get it.

First of all, most of the formulas that these guys use to make their sizing requirements for HVAC are based upon knowledge that engineers and mathematicians came up with for the standard home.  These are based upon something that does not apply to an earth home.  The factors are going to be different and, unfortunately, the HVAC pros don't understand this in most cases (in every case that I've dealt with).  So if you listen to a professional without educating yourself, you're going to end up with an oversized unit.

I can tell you that Jay Scafe (Terra-Dome) has lived in a Terra-Dome type of home all of his life.  He recommends a good air exchanger for ventilation and fresh air distribution.  He and Jerry both told me that when they were growing up, the home they lived in only had a wood stove for heat and they were fine.  In the summers (Kansas City area), the house was always cool and they had no A/C.

Things could be different here in Oklahoma.  We might have a little more humidity than they do.  It might get a little hotter here.  I don't know that it gets much hotter here though.  We're not that far south from them.  The topology of the property might be different from their's though, and so there might be some changes.  I'm hoping we'll put in the ventilation for an HVAC unit, but that we might hold off on it until after a year or two to see what we really need.  At most, I'm thinking it'll be a good filtration and ventilation system (like the one Jay has in his house).

We do plan to put in a radiant floor system.  We have that now in a couple of rooms of our house and there's nothing so comfortable as to step out of bed onto a warm floor in the winter.  We prefer it.

Why have a western exposure?

We are often asked why we have a western exposure on our house.  The answer is that this is how the property really orients.  We want the house to have benefit of solar warmth in the winter, so we're oriented towards solar south (not magnetic south), but we have a western exposure as well because this is where the driveway is.  This is where the road is and we just set it up this way.

It is true that a western exposure will be warming in the summer, but we're hoping to provide some shade and a lattice with green plants going on it, to provide some insulation from the sun.  By and large, the house will still be much more efficient than the average stick-framed home.

 

Radon?

What about radon?  We don't have as big a radon issue in our area of the country as some other areas due.  However, radon is still a serious factor to consider in building a home that is as air-tight as our's.  Much like water-proofing, there's really nothing that is radon proof either.  And much like water, radon is essentially an unstoppable force.  So we try to provide a barrier under the floor to slow it down, and then a path for it to easily escape outdoors.  This path will include a tube that leads horizontally beneath the slab to the exterior, as well as a plumbinig vent or two that will provide an easy path through to the exterior.

There are a number of websites that talk about radon remediation techniques.  Educate yourself.

 

Costs

We've had several questions about how much this house has cost us.  I'd like to answer that, but the thing is, that would be discussing our personal finances, which we believe is a private matter.  And the truth is, this information would not give you what you really want to know (unless you're nosey and just want to know other peoples' finances).  What most people really want to know is how much a house like this costs per square foot.  And right now, since it is in progress of being built, and incomplete currently, we can't provide that answer.

We are trying to keep track of costs and as soon as we are to the point where we can give a somewhat accurate figure on cost per square foot, we will do so.  This information could be of great use to anyone wanting to build a house like this.  It will allow you to compare costs with other types of construction, to determine if this is right for you.  At the same time, it allows us to spend what we feel we need to for our dream home, but leave out the costs of some of the perks, which would be irrelevant to other people that aren't going to have the same square feet, the same floorplan or the same details of the home.

If at all possible, when we do publish cost per square foot, we hope to do it for the structure itself, with a separate cost published for the siding we have on the parapets, as well as the cost of whatever siding we're going to put on the house.  At this time, we're strongly considering Novabrik, but we'll have to see what we can afford when that time comes.

Obviously, the costs of the exterior facade will vary, and so this is the reason we plan to break out those costs so that whatever you choose for the facade for your house, you'll be able to use the cost per square foot separate from whatever the cost of the facade for  your house will be.

Cost Comparison

We are often asked how expensive it is to build a house like our's, comparing with the cost of building a stick-frame home of the same size.  I don't have the exact breakdown at this time, but I can say it is more expensive (up front) but that you still have to take a lot into consideration when comparing costs.  For instance, we're doing a lot of the work ourselves, and so we're not paying a framing crew.  The house is up.  Terra-Dome did that for us.  So the initial cost is more, but maybe not that much more with the rising labor costs in framing.

Plus, this is a concrete structure, so it's going to require minimal maintenance.  So the on-going costs of living in this home will be much less than that of a traditionally stick-frame built home.

Since we have a roof with dirt and grass on it (or we will soon have one), tornados and high winds wont tear it up.   Hail wont damage it.  The sun wont damage it.  So we're not going to be going through the expense of re-roofing every 15 to 20 years.  And with the cost of a new roof in 20 years, whatever labor and material costs are by then, I'm not sure that the initial cost we're paying now is going to be more at all.

If you're really curious about cost comparisons, I'd check with Terra-Dome, Earthlog Equity Group, Earthsheltered Technology to see how they document this.

 

Is Concrete a bad product to use

Since people are becoming more and more green-concious, we've been discouraged from using concrete as a building material, because people say that it's not "green".  It's true that it isn't a low impact material as far as the environment is concerned.  However, you build once and you're done.  If built with the future in mind, the house will last much longer than if built with other materials.  Other materials, in the long run will require more maintenance, and whoever has our house after we're dead and gone, might not care about which building materials to use.  So maintaning the house could run into greater costs financially as well as environmentally.  Typically, we don't see that many other people care much about the environment.

We do believe that although some materials might not be "green" on their own, if they last much longer than greener materials, then in the long run, maybe it's not so bad.

For us, with the factors such as tornados, high winds, humidity, summer heat; we generally feel that concrete was the best choice for a building material.  Others might disagree, but in ten years, I don't want to be doing a lot of maintenance on the house.  With concrete, I wont have to.  The concrete roof will make that low maintenance as well.  With other building materials, there'd be some labor intensive maintenance that I either wont be able to do, or that I just prefer not to do.  Either way, concrete was a better choice.

 

Tax Incentives

We've been asked about tax incentives for building an energy efficient home.  There are incentives but they vary from state to state.  Check with the DSIRE (Database of State Incentives for Renewables & Efficiency) website, which is at http://www.dsireusa.org/.  Living in Oklahoma, an energy producing state, we have few incentives.  The energy producers want us to be wasteful and dependent upon them.  Other states will have better incentives.

 

Financing

When we tell people about the type of home we're building, we're often asked about how you finance a house like this.  I can tell you that people build these houses and so fianciing is available.  You just have to hunt for it.  It's getting easier to find than it was 20 years ago, or even 5 years ago.  If I were needing financing, I would check with Earthlog Equity Group at http://www.earthshelteredhousing.com/

There are other sources for financing, but this company builds the homes and has sources for financing lined up.  Their service offerings seem pretty good and so I'd recommend looking here, although I have no direct experience with this company.  I am on their mailing list though and receive updates from time to time.

 

Is Dirt an Insulator?

We've been asked about why we're going with an earth home.  We're asked why we want a dirt roof with grass on it.  We're asked if dirt is a good insulator.  We had an architecture assure us that we "don't want this kind of house" and told us that dirt was a poor insulator.  He was wrong and correct.

He was correct that dirt is not a good insulator, but he was wrong as far as us not wanting to do this.  We wanted to do it and we're doing it.

The point of the dirt isn't so much insulation in the sense that people think of it.  There is different kinds of insulation, and the point of it is what you're insulating yourself from.

Our summers are hot.  In the sun, our summer temperatures go over 100 degrees Fahrenheit.  The official temperatures are temperature readings in the shade, but the temperature in the sun is hotter and so in the summer, it's common to have temperatures above 100 degrees.  When the sun hits your roof, it makes the roof hot and the house inside it hot.  However, if you have grass on the roof and the grass is allowed to grow at least 4 to 6 inches, then the sun doesn't really hit our roof.  Our roof has dirt on it, and the dirt at the roots of the grass, stay cool and moist even in summer temperatures of 100 degrees.  This, combined with the transporation effect that the grass provide, pull more heat away from the house.

With the proper orientation of the house (we're oriented towards solar south), and the right overhang, the sun never hits the house.  In our case, the only time the sun will hit the house is in the early evening when the sun is shining from the west and hits our western exposure.  We hope to minimize this impact with strategically placed bushes, trees and a lattice filled with greenery.  We might also add a shade sail or two near the west side of the house to minimize exposure.

Now that I've addressed insulation, lets talk about heat storage.  The dirt on the roof and in the berm, can be thought of as an heat "battery" storing up heat in the summer, that can be released into the house during the winter.  Look at the PAHS (passive annual heat storage) references for further information.  The PAHS layer will provide for a more constant temperature in the house year round.

Wont It Be Dark?

My wife and I have had a laugh a few times when we've told people we're building an earth home.  Many have the same reaction, "Wont it be dark"?  "You'll have all that dirt on the roof".  "You can't see through it".

I'm thinking to myself, "Are you saying you can see through the roof in the home you're living in now?"

We will have a skylight in the living room.  But apart from that, why do you care that I have dirt on my roof?  You can't see through your roof either, can you?

The reality, if people had a chance to think about it beyond their initial reaction, is that our house will have more window area than most stick-framed houses have.  So it's not going to be dark.  With the number and the size of windows that we're going to have, I know that this house will have more than what our previous house had as far as exterior light is concerned.  It's not going to be a problem.

Insurance

Earth homes have had a problem with insurance from the very beginning.  Many companies wont touch earth homes because they don't have a "regular roof".  Even though a "regular roof" had greater vulnerabilities than one with dirt on it, the agents go with the little book, which is written by "little men" with "little minds" and this idea of earth homes, although not a new concept, is a new one for them.   In short, it's not what they're used to and they don't understand, and if they don't understand, they wont insure.

I've heard of some people getting insurance by insuring it as a "basement".  Others have put a fake roof over them to get the "traditional roof" to satisfy the little underwriters' book.  This traditional roof can be blown away in a high wind, but the underwriters love 'em for some reason, even though they don't seem to love paying to replace them when a high wind tears them off.

I asked Jay Scafe (Terra-Dome) about insurance.  His answer was that he lives in an earth home and doesn't have insurance on the house.  He has insurance on the contents, but not the house itself.  If you think about it, insurance on the house probably isn't needed.  A direct hit by a tornado might break some windows and doors, but the house will be saved.  The house wont burn and there's not much flammable material inside to burn.  We're on a hill so the place isn't going to flood.  Substantial earth quakes are a rarity in this area.  So there's not much to insure for.

However, if you really want insurance, if you look around enough, you can get it.  I'd check with Earth Log Equity Group about what insurance they know about.   There's also Earth Sheltered News (http://earthshelternews.com/) which might be able to point you to the right resources.

 

Temperature Beneath the Surface?

We're often asked what the temperature is beneath the surface of the earth.  Generally, we've heard that the temperature is constant around the world at around 55 degrees, just a few feet below the surface of the dirt.  This is a blanket statement that needs some clarification.

The standard way to discuss ground temperature is about 10 feet deep.  As a rule of thumb, you take 90 degrees Fahrenheit and subract the latitude of the location.  Our latitude is approximately 36 degrees.  So the ground temperature at 10 feet deep is 54 degrees.  Wait a minute.  That's not all.  It's 54 degrees at sea level.

For every 1000 feet of elevation, you need to subtract another 2 degrees.  So at our location, the ground temperature is approximately 52 to 53 degrees Fahrenheit.  Bear in mind, this is a rule of thumb and there are other factors.  Generally speaking, we believe that our house will be easy to keep cool in the summer, and in the winter, it'll be easier to heat.

If in the winter, the outside temperature is zero degrees, ignoring other factors, we wont be needing BTU to heat from 0 degrees.  We'll be heating from 52 degrees, so it's a lot easier to raise the temperature to 67 or 68 degrees than it is to heat from 0.  So there's an energy savings.

Now consider that this statement doesn't factor in exposed exterior walls and whatever heat loss/gain from them.  We do hope that with some solar gain in the winter, that our southern exposure will benefit us, rather than hurt us.

And we also know that the ground temperature is estimated at 10 feet deep, and because of our berm, it wont be ten feet deep everywhere on the walls.  So at some levels, the ground will be just a few feet deep (for instance, the upper portions of bermed walls might only be about 5 feet deep.  However, with the PAHS layer, we're hoping to gain the benefit and maintain a semi-constant temperature within the house.

 

Energy Savings?

As far as energy efficiency, how much can we expect to see in savings in an earth home?  It can easily be stated that an earth home can save up to 80% in heating and cooling.  Many earth homes never get below 50 degrees with no heat source, even in the coldest of winters; and rarely get warmer than 75 degrees without any A/C, even in the hottest of summer.

 

Turnkey Earth Home Systems

We are often asked if we weren't planning to do so much of the building ourselves, are there any "turnkey" systems for building these types of homes.  The answer is yes.  We list a few here:

I'm sure there might be more turnkey companies, but these are the ones that I've got information about.

 

CBUD: Call Before You Dig

Years ago, I worked at a telecommunications company where we designed and built one of the first, if not the first, CBUD (Call Before You Dig) systems.  It was called CBUD, of course.  There are different acronyms today.  A friend commented on our progress report that our utility issues might be partially solved by calling the Call Before You Dig (most states have these numbers and/or a website) where you can make a request for the various utilities in your area to come out and mark their lines.  The phone company will come and out spray paint the ground in the path where the phone line is located.  They have done this on our property and mark from the street all the way to the house.

It's good to call CBUD and we will for the phone line.  The rest of the lines will have to be located by us though.

As far as electrical lines, the utility will mark any lines of theirs, up until they reach the meter.  From there, it's your baby.

We have an electrical line going from one shed to another, as well as water and a phone line (in the same trench).  The utility wont check this, but if I had te sensing equipment, I could do it.  Maybe I'll see about renting one, if there's one to rent.  I don't even know what the thing would be called.

As far as our irrigation line to the pasture, that's pvc and is undetectable without some kind of cheap metal cable or wire in the trench with it.  When we ran the irrigation line, we didn't know about those things.  We sort of know where that line is and can dig it up to locate it and prevent a backhoe from getting it.

We currently don't have a propane line in the way, but if we did, they're copper and I believe that line would be detectable.

Call Before You Dig is always a good thing to do.  When I know for sure what we're going to have to do as far as running utilities I'll call to get the phone line located.  From past experience, they can usually get you within a foot or two of the actual location of the line.

Oh, and by the way, the CBUD folks come out and mark your line locations for free.

 

Our Location

We live in east central Oklahoma.  I'll eventually give more detailed location information, but I'm not really set up for visitors right now and so I'd prefer to just provide a generalized location as it pertains to climate and the issues of heating, cooling, tornados, rainfall, etc.  Once I get the house closed in, I'll probably be more interested in tours for whomever might be interested.