wofati eco building

Good idea, Paul.  thx

paul wheaton wrote:
So you might cut your costs by 70% and then use half of that for architecture and engineering stuff. You still come out dollars ahead.

An innovative project, rooted in sound ethics, might also help attract a bright, energetic, and good architect and/or engineer.  This sort of work might even play into price negotiations: not just a good deed, but an investment in an iconic portfolio entry.

Which is to say, you might get more for that money than just official approval: I'm as much a fan of DIY as anyone, but a fair share of good ideas come from the professionals.

Kathleen Sanderson wrote:
If you live where there are lots of paper birch trees, and if you need to clear some of said birch trees for garden area and so on, the birch bark can be recycled as a roof membrane.  There are old sod-roofed cabins in Alaska and Siberia that are fifty or more years old with that type of roof.  Birch bark kept damp just about lasts forever.  I suppose it might need to be stripped off and replaced once in a lifetime or so, but for anyone in the far North with access to plenty of birch bark, it's probably the best bet.  There may be other long-lasting barks in other areas, too.

Kathleen

Hey, Paul, it looks like she's found your pre-Columbus membrane material!

I've read elsewhere that birch trees under about 10 or 20 years old can be coppiced.  As long as the bark doesn't need to be particularly wide, that would be a way to save up a useful amount of bark in a reasonable amount of time.  Cutting the bark off in a 45 degree spiral might help produce wider strips from smaller wood, though I guess it could lead to other issues.

Yes - the birch bark angle sounds cool!

Paul try this site. go about 3/4 way down.
http://www.de12ambachten.nl/enggreentech.html#anker72066

Hi Paul and Chuck, I'm curious about this idea of getting an engineer to sign off on this type of building or, as Ernie and Erica have done, gone through the process of getting the rocket stove bench approved by the City of Portland. This would take some kind of savvy engineer and perhaps a lot of dough. Do you know of any engineers who might want to take on this kind of effort? We are going to be building a small home on the land next door to us for my mother, she really is taken with the hobbit house from Whales and/or Mike Oehler's designs...it's just that we're in King County with Uber Control on building...suggestions on that welcome! Thanks for the great WOFATI piece and discussion Paul.

I went through something similar with my planning department  -  Having blue prints and an engineers stamp was just a way to come across as serious and official.  It didn't mean the engineers of the planning department were going to agree or give their go ahead. 

So if I were you I would meet with the guy at the building department who is for straw-bale construction, ask the receptionist.  Ask a lot of questions about modifying the basic building specs for strawblale and/or cob if they offer these permits (feel the situation out).  Find out what engineers/architect he recommends for Alternative Building, and ask what are the biggest problems they see people making along these lines.  I wouldn't give him much info about your plans or ideas yet, remember you are not making a formal submission at this time.  Ask for copies of any paperwork you will need to supply when you do apply for permits.

Some digging and research will go a long way to help you get around a dead end

Blessings!

I don't know of the person nor am I certain of the exact process. 

What i do know is this:  there are some very interesting things that are built, and they are allowed to be built because engineers say it is fine.  I once met an engineer that said that he had a friend that built something bizarre and he was called in to give his stamp of approval to say that it was structurally sound so that this odd structure could be built. 

Kragonfire wrote:
Paul try this site. go about 3/4 way down.
http://www.de12ambachten.nl/enggreentech.html#anker72066

I've seen that page before.  It has lots of good stuff!  The key is that it mentions leaf mold and how quiet these are.

this all sounds pretty good to me.

my problem is water table: the land available to me is in the North Fork Lewis River flood plain.  there are three dams upriver, so floods are rare, but they do happen.  even without a flood, the water table is sometimes pretty high, which could remove the insulating value of the dry soil during and for a while after high water.  being a river valley, the subsoil is exceptionally sandy and well-drained.

also, the land doesn't have much slope to speak of, except at the river bank.  there are a couple of places with a little bit of topography, but I would say the whole property only varies about six feet elevation wise apart from the river bank.

so, is wofati inappropriate for this land?  should it still work?  with some extra steps?  anybody want to drop by and build a house with me?

tel wrote:floods are rare, but they do happen. even without a flood, the water table is sometimes pretty high, which could remove the insulating value of the dry soil during and for a while after high water...also, the land doesn't have much slope to speak of, except at the river bank. there are a couple of places with a little bit of topography, but I would say the whole property only varies about six feet elevation wise apart from the river bank.

It isn't just about insulation: I think the wood of the structure would rot if the water table rose to touch it.

I don't have expertise or experience on this one, but it sounds like some significant earthworks would be in order:

[li]Some shaping downslope that creates microclimates and allows you to benefit from the occasional flood by holding whatever it brings you, plus[/li]
[li]An area piled high with earth taken from downslope, to keep structures and other flood-vulnerable landscaping above the water table[/li]

Perhaps you could scrape up topsoil from the places that need shaping, and grow insulating straw from it while the structures are built and the deeper earthworks are accomplished.  The option of building on fairly level ground and then covering it over might make the whole project a little easier.

This is something that definitely is not for areas that flood. 

sweet thready!

two cents and some...

Kragonfire kind of hit on it in that the posts have to be treated or they have to be a form of wood that is very resistant to rot like cedar, white oak, black locust, etc. If not, you will have it rotted out within 10 years and possibly if the conditions are right within 3 years.

ive pulled up so many treated posts I cant even count them. my experience with it is that a 4x6 douglas fir that is treated with cca last no longer than one that is not treated if it is in ground contact. this is because the inside is not penetrated bythe toxins, and as such, a great hide our for chewer/shredder/decomposers. so they often rot hollow and look good but have no structural value.

boots.

boots are important because the control wicking. most SB and cob houses have ground contact floors. a barrier, or boot, is needed. the boot is not only the stem walls of the foundation, but the vapor from the floor.

the temperature in your building will often be higher than the soil around it, drawing humidity which will condense on vapor barriers or enter the living space. in the case of the later, it needs evacuation.

most conventional buildings deal with this by having ventilation under floor spaces, wrapping the house and halting vapor rise from the ground by crossdraft venting under the floor.  most natty buildings with ground contact floor breath through the walls to the air to remove this vapor.

that said, i dont know how oehler deals with this issue. Ill have to look at his designs.

your building paul, as I understand it, is designed with posts. This allows for a vented floor, like the conventional buildings I mentioned. but if you plan to build in ground contact, ie. without a floor that has a draft under it, I suspect youll need a vapor barrier under you building, with drains, to collect and evacuate the vapor that condenses.  since your roof has a barrier, and our walls likely will as well, you will be condensing alot of moistureon the exterior and wicking rain down your external interstices. you'd have to wrap the whole thing like a boat with side barrier tarps extending beyond the base perimeter in order
to prevent infiltration of vapor/condensation.

unless im completely missing something, which isnt uncommon.

more reseach. oehler...wofati... malcom wells...  yay!

http://www.richsoil.com/images/hobbit_drawing_elevation.jpg

answers my question about ground draw vapor. this design does employ both draft space (vented straw, which i would suggest against, as it will still decompose- perhaps perlite or charcoal? ) and a "damp proof membrane" which I assume to be equivalent to a vapor barrier.

gosh, i cant wait to get my camera and notepads when I get home... online shareware ecosavvy design books were making! nice article over there w/ the above picture, paul. thanks!

The whole structure is wrapped in plastic at any point that touches soil.  Sort of double wrapped in plastic.  And there is a layer of newspaper in addition. 

I do think there are valid concerns about warm humid days and the cool walls.  But!  I think those concerns are greater with Oehler's original structure and reduced with the wofati due to the extended umbrella.  So the average temp is closer to 70 than to 50.

If the land you have to build on is level, can you create slope to use
for wofati?

Also, just how dry is that 20 feet around the house?  Does that Hobbit-like housein Wales that is pictured have a 20 ft. membrane around it?  I see that they have grass and some other things growing there.

      Thanks,
      Shivani

Shivani wrote:
If the land you have to build on is level, can you create slope to use
for wofati?

Oehler has a lot of designs for flat lands.  I have to say that I think it is possible to build on a flat land, I would be concerned about flooding and how to get the water away from the wofati.

Shivani wrote:
Also, just how dry is that 20 feet around the house?  Does that Hobbit-like housein Wales that is pictured have a 20 ft. membrane around it?  I see that they have grass and some other things growing there.

The one in wales is not a wofati.  But you can see that it is close!

Winter squash belong to the genus Curcubita, within which there are six different varieties.  The squash of each variety cross readily  ust how dry is the soil for 20 feet around a wofati house with plastic sheeting down?  What can grow there?  (The photo of the European hobbit-like house has plants around it.  Did they do the 20 feet of plastic sheeting?)

Also, can a wofati house be built on level ground, by mounding up some of the soil?  (We are looking at a property with a totally flat place to build on.)

Thanks,
Shivani

Uh, is my last post not showing up in your browser?  Maybe there is a browser caching problem?  If you can see this post, please reply.

Yes, now I see your two replies.  I guess I didn't see them earlier because I hadn't realized this thread had a 2nd page. 

Anyway, if you have ideas about how to build wofati on a level plot, please share?

Also, if one DOES put plastic sheeting out 20 feet all around the building, just how dry does that make the ground?  Will it be possible to grow plants in that area?

Thanks,
Shivani

level plot:  Take a look at Oehler's book.  He has lots and lots of designs featuring a level plot. 

I'm skeptical of doing this where it is level - I worry about flooding and the like.

The plastic sheeting is typically one to three feet deep.  So growing plants above that is easy. 

Might check the water table under that level ground...and monitor the water flow during heavy rains. I have some level ground on the south west corner of my property that would be no problem, especially using Paul's 20' of plastic wofati concept. Also some level ground on the northeast side. It's maybe 75" lower and is a natural basin for runoff from several acres to the northwest. Probably wouldn't be a good idea to try it there.

Maybe someone has mentioned this and I didn't see it, but the name "wofati" is ridiculous! I read the article and could not understand what word Mike Oehler used that was such a turn-off -- I had to read through it a few times before realizing that "underground" was the word that Paul (and others?) found offensive.

"Underground" has no negative connotation for me. Actually I think back to "Wind In The Willows" and Badger touring his burrow with Mole -- nothing but fondness for living down below! It's like "above-ground" house as far as I'm concerned -- I have no overall prejudice against above-ground houses even though I would not want to emulate 90% of those (in modern America at least: trailer, McMansion, soviet condo block).

"His choice of title was so bad, that I avoided the book for more than a decade." Are you kidding me? "$50 Underground House" is exactly the kind of phrase I want to hear.

As I read in your article that "when Mike tries to talk about his work, people automatically tune him out whenever he uses the word. Feel the mighty power of a single word!" -- I thought at first that you were talking about the word "wofati"... ha!

I don't want to pile on too badly here but "wofati" sends me into a fit! "Whoa Fatty Fatty!" Ever listen to the Heptones or Clancy? Please get your marketing team back together and pick a better name from the hat!



http://www.youtube.com/watch?v=qrsEYgz2TqE
http://www.youtube.com/watch?v=VRWed_9U3w4

While "underground" has no negative connotation for you, it does have a negative connotation for me and about 90% of the people exploring housing (IMOO). 

And, the negative aspect probably has less to do with being below grade, and more to do with the idea of living in a basement, or stories we've heard of underground houses that have failed. 

This is probably equal parts generation gap, regional culture, and just aesthetics between the two of us, but here in western PA, and where I've lived in Hawaii, Massachusetts, Michigan, and the Bay Area, the word "underground" never drew any negative connotation, in the last 10 years as a carpenter talking with people about alternative buildings. So I must just have missed that boat. No resistance to the word has ever come up. I've seen the problems of underground houses decried in many books, but not the way you presented it!

I enjoyed your very nice article, and I'll take some lessons from it, but I'll just keep calling it an "underground" house! The "Wheaton" earth-sheltering method. I don't plan to ever say "wofati" but if I run into someone who does, I'll let you know that it's catching on!

Also, "Wo Fat" was apparently a villain from Hawaii Five-O. (Never watched it.)

paul wheaton wrote:
There are ways to do it by the books. 

Consider that the wofati is going to save you heaps of bucks.  So, my understanding is that you can follow a few different paths and still do it.  One is to have an engineer sign off on it - that sort of overrides the safety codes.  (emphasis on "sort of")  So you might cut your costs by 70% and then use half of that for architecture and engineering stuff.  You still come out dollars ahead.

I admire your enthusiasm but you'd be hard-pressed to find a licensed Engineer to "sign off" on this design, as proposed, without major modifications.

That said, those engineering costs and extra price to build as per those stamped plans will most likely negate the perceived savings. And depending on the sticklerness of those in charge of the planning department, it's entirely possible this concept would turn in to a very expensive project...assuming they'd even accept it.

Not trying to rain on anyone's parade. Just basing this from my near 20 yrs of architectural design and collaborative work w/ engineers and building departments. It is unfortunate, but in order to build something other than a standard home w/ green veneer, we often times have to either build clandestinely (not always a viable alternative) or find "freedom pockets" as Michael Reynolds calls them (areas that don't care what you build).

I think that these so-called "freedom pockets" are the spots where innovation happens and then the designs can find their ways into building codes 20 years later.

paul wheaton wrote:
I think that these so-called "freedom pockets" are the spots where innovation happens and then the designs can find their ways into building codes 20 years later.

These "freedom pockets" certainly have some innovations... but they typically have more failed experiments and rickety trailer house build arounds than anything.

Unscrupulous or unknowing, some times these places get sold to the unsuspecting home buyer who later realize they have a mess of ongoing issues to deal with. I have seen major structural problems caused from lack of engineering knowledge and moisture damage....and homes condemned due to Stachybotrys and Chaetomium. Remediation can be costly.

So, because of this -and property value concerns- I'm not at all opposed to the enforcement of building codes.....IF they were written around low-impact living and building. They are not, though.

Carry along -clandestinely if needed- but do so with enough knowledge to, at the very least, minimize issues that can creep up.

I think every person should have the right to build and live in whatever goofiness they want.  And if an unsuspecting person is gonna buy said goofiness and they don't know what goofiness looks like .... well, I thought that's what inspectors were for.  Surely a bank isn't gonna loan money unless there is a COO. 

I too would like to see more freedom even at the expense of poor construction. 
This idea that rules, conformity and laws make life better I find incredulous.

Life should involve a little mess.

The idea must come form growing up as children, as adults we still want someone else to watch out for us, protect us from ourselves and set rules for us.  We make foolish choices and want to sue someone.  I personally would like more freedom (or some of my freedom back) to make my own mistakes - JMO

I understand your opinion Rusty being that this has been your job, and I respect that.
I just don't happen to agree, no offense intended to you or your profession.

Sorry about hijacking the thread Paul, but you hit on a nerve with me.

Jami McBride wrote:
I too would like to see more freedom even at the expense of poor construction. 
This idea that rules, conformity and laws make life better I find incredulous.

Life should involve a little mess.

The idea must come form growing up as children, as adults we still want someone else to watch out for us, protect us from ourselves and set rules for us.  We make foolish choices and want to sue someone.  I personally would like more freedom (or some of my freedom back) to make my own mistakes - JMO

I understand your opinion Rusty being that this has been your job, and I respect that.
I just don't happen to agree, no offense intended to you or your profession.

Sorry about hijacking the thread Paul, but you hit on a nerve with me.

No offense taken, Jamie. However, I'm not clear on what you don't agree with. Perhaps I wasn't clear. I am all about freedom and being able to build what we want. With that though comes the inevitable downsides...and some times, it ends up costing either the builder or the new owner a lot of money and headaches...or health in case of certain molds. Building codes and their enforcement isn't in itself a bad thing. It's the fact that the codes were and are built around a seriously flawed lifestyle/system...and, as unfortunate as it is, that isn't going to change to much extent any time in the near future.

Really, from my perspective, codes and big government wouldn't be needed if people could self-police themselves. Unfortunately, the general populace has proven that it can't. If it could, we wouldn't have wide-spread pollution, lowering water tables, raped and pillaged landscapes, etc, etc. That's when Uncle Sam steps in, like it or not...and I don't but....you and I can't personally control all the bad apples .

But I digress. What I'm getting at is that we really need to be careful when building alternative homes for which there are no cookbooks for. There are countless well intended alternative homes of all styles that were constructed with a lot of love and enthusiasm but often times too little research or knowledge. Then, when problems arise, it gives the whole low-impact living movement a black eye....and Uncle Sam another reason to step in.

But let it be clear. I'm 100% for alternative homes...so much so that I discontinued work on conventional homes in 01...even knowing I would lose most of my design income. So, in summary, what I'm saying is this: lets do it but lets do it well enough to inspire those who might otherwise turn their noses....and of course, well enough that Sam will stay out. Lets police ourselves.

(for what it's worth, I plan to build in a "freedom pocket" )

Does that clarify my point of view a little better?

Well put Rusty, I'm glad your in favor of unconventional designs.

I would add that I do believe many bad results are because someone was trying to avoid permits and accepted methods to get around unflexible and expensive code regulations, and not because people were trying to build something better and more natural. 
So 'codes/laws' are not just all good, they cause some of the problems too.

I wish my building department had the agenda of wanting to help me not make serious building mistakes, but that is not the culture in that government department I can assure you.  Last time I check one had to purchase a septic permit even if you were not going to put in a septic system ever!  They allowed no other waste permit, such as contained system composting.  I asked and yes, after I paid their $3000 permit fee and could then buy and use my composting toilets.  Now that's just stupid!  And all about their job security and getting the money.  Why do we set up government agencies that then robs us in the name of safety?  How is them getting my $3000 keeping waste out of the ground water?

To hear them talk sounds a lot like what your saying, very concerned and prudent, but the truth is they want my thousands no matter what - to pay for the running of the department, to pay for the guys driving around trying to catch un-permitted projects, etc. 

I'm sorry, but when I think intelligent design and safety, I do not see building codes supporting that.  All I see is the game and politics.  I don't blame individuals, everyone is really doing what they think is right, I do blame the system, it isn't good.

I made a couple comments on your french drain thread, but now I see your problem.  You need to divert water around a sunken living space, not around an above ground space.  You have actually two issues.  One is surface runoff and the other is the water table.  On a slope as you are talking about surface runoff will be minimal as long as it there is grass.  However, water soaks in all directions so you will want something to block sepage above your structure.  In this case, a french drain will work fine as is it will create a block.  I can tell you emphatically that water flows from larger to smaller holes not the other way around.  Creating a french drain with gravel will block water from seeping from the surrounding ground to your structure.  The bigger possible problem is if the water table rises to above your floor structure.  Ground tables are complicated and are not always horizontal, actually they are more likely parallel to the ground, but that is putting it a little to simply and this is critical to your structure.  You definitely do not want water hemoraging from the walls.  But aren't you already going to be lining the walls with plastic?  If so, I don't see any problems.  I have never built one of these style houses, but I am sure that plans for these type houses have already solved this issue.

I added a video to the article showing Mike Oehler's greenhouse.

Hey Paul
I know some of the drawings in this post are older than your wofati article, so you may have revised some of your ideas, but I wanted to just note that Malcolm Wells warns against having a vertical wall at the edge of a deep earth roof. When freezing occurs, it can damage the wall. Your more recent drawings show the roof tapering to the edge.
Jim

Jim,

I guess I don't understand.  Can you run this by me again?  Maybe saying the same thing a different way will have the words so that my brain can get wrapped around it.

In your June 18, 2009 post, you included two pictures with a vertical wall at the right edge of the roof. The first had earth all the way up to the top of the wall, the second had earth that sloped down to the base of the wall.
Malcolm Wells commented in one of his books that the vertical wall at the sky end of the roof with earth upto it was a bad idea because water in the earth would freeze and do expansion damage to the wall. It sounded like one of those lessons learned the hard way.
Rob Roy's more recent work and Malcolm's drawings/pictures seem to be recommending using sod to act as the retainer at the edge of the roof.
In your wofati article, you dropped the vertical wall in the similar drawings, so you may have already abondoned the idea. Just in case I thought I'd say something

Another thing I've been thinking about. In order for the passive annualized solar to work really well, I think you need a large uninterrupted section of ground covered by insulation and pond liner. If you start putting in 4th wall windows you will be compromising the heat retention. If PAS is the gameplan, I'd be careful and use few if any and very small openings off the South wall.

Silver wrote:
In your June 18, 2009 post, you included two pictures with a vertical wall at the right edge of the roof. The first had earth all the way up to the top of the wall, the second had earth that sloped down to the base of the wall.
Malcolm Wells commented in one of his books that the vertical wall at the sky end of the roof with earth upto it was a bad idea because water in the earth would freeze and do expansion damage to the wall. It sounded like one of those lessons learned the hard way.
Rob Roy's more recent work and Malcolm's drawings/pictures seem to be recommending using sod to act as the retainer at the edge of the roof.
In your wofati article, you dropped the vertical wall in the similar drawings, so you may have already abondoned the idea. Just in case I thought I'd say something

I get it now!

My motivations are a bit different.  I would think that as far as freezing goes, I suppose there could be some problems in that space - although I would think that as time passes there will get to be a gap there anyway - as stuff starts to sorta go downhill.

Silver wrote:
Another thing I've been thinking about. In order for the passive annualized solar to work really well, I think you need a large uninterrupted section of ground covered by insulation and pond liner. If you start putting in 4th wall windows you will be compromising the heat retention. If PAS is the gameplan, I'd be careful and use few if any and very small openings off the South wall.

I would say "it depends".

For one thing, I think more openings to the south, the better .... well, to a point ... but I think more glass to the south is generally better than more glass to the north.  Although if you do enough of the thermal intertia (TI) stuff, you probably don't need to worry about it too much. 

And that leads to the TI subject. 

If you do things strictly oehler style, with no dry TI, then you end up with, around his place, where your deep TI is about 54 degrees and since your up close TI is probably around 35 degrees, then your indoor temp (without added heat) is around 40.  And then if we look to the other end of the scale, your deep and up close TI is probably around 70 and on a cold day, your indoor temp (without added heat) is around 65.  If you add lots of insulation and minimize windows and lots of other things, you might get it to be more like 69.

Now, suppose you do something in between.  Maybe some deep mass is around 70 and some is around 60 and some up close mass is 70 and some is 50.  And so your indoor temp (without added heat) is around 55. 

It is still a significant improvement. 

So then it gets to be a design of what is fun to live in vs. the ultimate TI.