While sourcing to build your own home, you can find out all sorts of interesting things about the industry.  Of course, a lot of money goes into the housing industry, and along with that money comes incentives for various groups and corporations to game the system…  Here are two short examples.  For a third one, consider the Low-E, High SHGC controversy on the Windows Page.

Flush-less urinals

A typical toilet uses a lot of water to flush away a liquid.  Euro toilets have a second “number 1” button that uses much less water.  A urinal uses even less water, but still a lot.  A “flushless” urinal uses no additional water and with two boys, could save me thousands of gallons a year.  I asked a plumber about it and he said “no, those are very dangerous, you shouldn’t install one, they aren’t even legal in most states”.  Well, I have seen them in many airports and public buildings, and I know that the US Core of Army Engineers has switched to flushless urinals exclusively, so that didn’t sound right.

TO THE INTERNET! for research.  I found a lot, here is one with some good numbers and details, and here is one source that had a nice video, but here is the jist of the story in my own words.

Illustration of how the Falcon Waterfree Tech flushless urinal works… This is really the money maker behind the business as it represents a continuous revenue stream (no pun intended)

These flushless urinals are more common in Europe.   An american business man (James Krug, ex-exec of Disney corp and big donor to Al Gore) thought it would be a good green business opportunity here in the USA and started a business, Falcon Waterfree Technologies.  Not being totally altruistic, his design is based on a cartridge fluid trap that need to be replaced periodically at $40 a pop, but it would still be much cheaper than all the water that a regular urinal requires. I personally prefer the H2Zero model by Caroma because of its longer lasting trap design.  Click Here for a demo video.

James and others in the industry were “blindsided” by the plumbers union.  Of course, the union claimed it was a public safety issue and had some unqualified hack write a ridiculous report (based on no research, she had never even seen a urinal before being hired) to support their position that the urinals were actually “deadly”.   You don’t need to stretch your imagination to suspect that the union was actually more concerned about the fact that people who install flush-less urinals wouldn’t be paying plumbers to install water lines or do as many repairs.  Whatever story you believe, the building code was actually adjusted to ban the flush-less urinals.  But James Krug couldn’t let that happen to his fledgling business, so he used his connections to push the green angle.  So now the Democrats (yes it gets political) were on both sides of this one. They had union lobbyists trying to keep the plumbers paid and they had environmental groups lobbying for the water savings…  They had to come to a solution that made everyone happy, and they did, sort of.  The residential building code was adjusted so you can now install one of these flush-less wonders, and save all the water you want, but only if you also have water lines run to it (preferably by a union plumber ;^).    That is what political compromise looks like.

Steel stud framing

The front wall of the main portion of my home will not be earth sheltered or significantly load bearing… As a result, I am planning to use 6 inch steel stud framing.  This was definitely my architects preference (over wood studs).

We could not use ICFs for that south wall because there are too many windows (and not enough structure) to support the weight of the concrete above.  I guess we could have used ICFs below the windows, but the startup costs would be too great.  Also, ICF can be made to handle curved walls, QuadLock does it better than others, but it is still relatively expensive.

There are many advantages to steel studs, including reduced cost, longer life, increased precision, no chemical treatment, etc.  From an environmental perspective, wood is renewable but the steel is much lighter, longer lasting and very recyclable…   The only clear downside is excessive thermal bridging with the steel studs. Even though these steel studs are thin, they still act like a heat conduction highway.  In addition to allowing the heat out via high speed conduction around the insulation, they also produce cold spots on the interior walls that can result in condensation and visible ghost lines as dust and soot in the air get stuck in the condensation.

As usual, when looking for a solution…  TO THE INTERNET!!!

I found lots of very interesting papers such as this one or this one. They all seemed to be about 10 or 12 years old and they included lots of interesting ways to reduce the heat conduction…  The three main categories were;

1. cut slits or holes into the stud to increase the distance the heat must travel thru the stud (like a maze).
2. Stamp the faces of the stud to reduce the contact (conduction) with the wall coverings
3. wrap the stud or the whole wall with insulation

The first two options are just a stamping process and could actually reduce the weight and cost of the studs while improving the thermal performance.   However, they did require an investment in research to figure out how best to stamp the steel for minimal conduction with maximum stiffness.  The third option is the simplest in terms of technology, but increases the cost of building considerably.  The third option could be done by wrapping each stud individually or by sheathing the wall its self, which is the most expensive because it uses the most foam and then also requires special attachment of an exterior covering to protect the rigid foam sheathing.   So, clearly improving the efficiency of steel stud construction would be in the best interests of the home owner, the steel companies and the planet.  Clearly, there would be a lot of money available for research and the winning design should easily take over the market…  But the steel companies didn’t count on the power of the petrochemical lobby.   While the steel researchers were busy figuring out a better steel stud, Dow Chemical and others were lobbying and adjusting the building code so it now requires all exterior steel stud construction to include insulation sheathing.  This undercut the innovative efforts of the steel industry and I couldn’t find any companies that sell the more advanced steel studs.  (Update, actually, now MarinoWare does sell studs like this, but you will need to special order to get them).

Here is a gallery of pics to illustrate…

This is another monthly update.  On the one hand, things have moved really slow this past month, on the other, I am pretty sure I left it too long between updates and have forgotten a bunch of stuff…  I really should bite off smaller updates more often…

Confidence meter

My actual confidence gauge moves slightly slower than this, but this should give you an idea… I worry about time, money and ideas…  But some times, a great idea pops into my head that helps me figure out how to save time and money and everything is good again for a while 😉

There are days when I am so sure this earth sheltered home idea is the best idea ever and I am pretty confident that I will be glad that I took this path.  I am actually pretty confident about the sound principles underlying the earth sheltering concept, but in the end, “the distance between insanity and genius is measured only by success” ~Bruce Feirstein.  I worry that perhaps I don’t have enough money or time or ideas to get this done correctly.  Perhaps I should have designed a much simpler home like BD’s hobbit hole?  Or at least if I knocked the square footage down or dropped some of the fancy ideas, like the storm room tower, I could come up with a more practical design?  For a while there, Sherri and I had this idea of connecting some Quonset huts together in a very affordable way, that was pretty practical.  Were we greedy or arrogant to want something more “architecturally interesting”?  We plan to counter the lofty architecture with simple (affordable) material such as polished concrete floors, but will it be enough?  We have already invested quite some money with the architect and engineer, but that is no reason to keep heading down the wrong path… If it is a wrong path…

Then I will have a good idea or some other moment of inspiration and my confidence level goes up again.  Overall, I have more confident days than days when I think I should probably call it quits and spend the money on something else.  I suppose being overly confident would also be a bad thing…  I know enough to know this won’t be easy, but can I get it done (downward cycle begins again…)

Visit to Battle Creek

The prairie dog exhibit at the Binder Park Zoo was very relevant to my earth sheltered day trip. They let you get much closer than other zoos.

Last month I drove out to Battle Creek to visit an earth shelter under construction.  Since we took the kids (my boys are 6 and 8), we also visited the Binder Park Zoo, I particularly enjoyed the prairie dog exhibit   I arrived at the earth shelter on the last day of the steel being erected.  It was very interesting to see the last 4 steel Ibeam arches get bolted down and tied in with the rebar.

Here One of the homeowners friends is helping to position one of the last steel arches into position. The arches are bolted to brackets set into the floor and connected with rebar placed into the Z-brackets and hammered tight to lock them into place.

I had read a lot about Formworks homes, but it is still interesting to see it first hand and to talk with the homeowner about his challenges.  For instance he had to work out a way to lift the heavy steel into position after his first plan (a rope) slipped and resulted in his wife cracking her wrist.  His final plan involved building a wooden jig that the forklift could easily pick up, but which had lugs to hold the steel directly without letting it swing.  Of course, I took lots of pics and jotted down some notes after I got back in the car.

I absorbed lots of little suggestions like making sure that my shotcrete guy rents his own lift (liability) even if it cost me a little extra, or thinking that if the earth had been piled a little further from the home, it would have been a lot easier to move the equipment around or drain the site.

Some of it was just touching the actual steel, feeling the weight of the rebar was and how flexible the steel Ibeams were over such large spans.  I really left thinking that I could do a lot of it myself (and save a lot of money).  However, there were a couple things I saw that made me rethink some aspects of my design.

Here you can see the bracket, the cold rolled IBeam, and the Z-brackets (one hammered closed). The little white tubes are 6 inch PVC sections set into the concrete to make it easy to place the vertical rebar.

The first was about the importance of the little Z brackets found on the edge of the IBeams…  The Battle Creek home uses a proven Formworks steel arch approach.  Formworks fabricates the steel arches from cold-rolled IBeams.  On the outside of the steel arches, they weld little 1 inch Z clips so you can easily drop rebar in and hammer the clip down to tie the flexible steel into place.  Erecting each one was really very simple with this approach.   Later on in the process, they put 2 inches of insulation on the inside, hooked on the inside of the IBeams.   When they add the spraycrete from the outside, the 2 inches of insulation keeps it on the outer half of the 4 inch IBeam and the cement completely covers the rebar.

We are using steel arches, but our process is quite different.  I didn’t want to do the process of adding the insulation only to remove it again, and I didn’t like the look of the final surface that resulted.  Instead, we are wiring the form work (pegboard) to the inside of the arches, this means the full IBeam is cemented and if we had rebar on the outside, it would not be centered enough to make the engineer happy.  Eventually, I will add a structures section to the website to explain why the location of the rebar is important…  At our last pow wow, we had decided that the only good solution was to drill holes in the steel arches (as part of the manufacturing process) and thread the rebar thru them after they are erected so that the rebar is positioned correctly in the cement.

This is a typical cross section of a Formworks wall. The Ibeams are manufactured with the welded on Z-brackets for easy field assembly. The lattice of rebar is wired to the outside and rigid insulation is installed on the inside as a temporary backer board for the shotcrete… Later, the insulation is removed and placed outside the structure during backfilling.

As I was watching the assembly process in real life, I was trying to imagine how I would manage it with the drilled hole method…  It would be a lot harder to thread the 20′ or 40′ long pieces of rebar than it would be to just drop them in place, and more so if the rebar is bent first.  Also, our drilled hole design does not have any way to lock the rebar in place nicely.   With the Z-brackets, we could just adjust the wobbly Steel until it was plumb and then hammer down the clip to lock it in place…

I was very happy to see these round 1.5″ pipes used as arches. They weigh about 2.2 lb/lft which makes them much cheaper and easier to work with than the larger IBeams (7.7 lb/lft) used on the wider spans.

The battle creek house had two large domes, one 40ft across and one 50 ft across that really needed the strength of the steel Ibeams to carry the load.   However, it also had some narrow vaults (12ft?), which were similar to the span I used in my design.   My second big discovery was that the Formworks engineers had specified that they be built with only 1.5 inch steel tubing.  Formworks has designed many earth sheltered homes, so I trust the experience of their engineers.   Those relatively small tubes could be huge for my earth sheltered home.  First of all, the steel tubing is much cheaper than the 4 inch IBeams, both to buy and to bend.  They would be much lighter and easier to erect also.  It also occurred to me that switching to the 1.5 inch bent tube would also solve my assembly problem by letting me use the Z-brackets.  If I tied the forms to the inside of the steel tubes, I could still use the Z-brackets to hold the rebar and it would be at the right depth in the cement.

I decided that I would need to talk to my engineer about it.  I prepared a nice ppt presentation with images, etc. (I have not yet got permission to share the pics I took there on my website) and sent it to them on Sept 6th, but have not heard back.

I plan to head back out to Battle Creek when the shotcrete work is done…  And then hopefully again for the waterproofing…   It is amazing to me that the giant 50ft clear span domes only calls for 4.5 inches of concrete…  and will support an earth load that is 3ft deep at the top of the dome…  Between the domes it will be more like 15 ft deep.

Design Team

The plans have not really been updated very much over the past month (or two).  I have got several drawing sets from the architect because I asked for weekly updates, but it is often hard to find many changes.  Each time, I review and send back a list of the new issues I have found.  Sherri thinks I should skip the emails and just phone them.  I did that a couple times, but I like the written record.  At the moment, the architect seems busy with other projects, so I am far ahead of them in terms of reported vs resolved issues; but when they finally have time to get around to it, they should be able to go thru all my emails and check off all the changes in a straight forward way.  I figure it is easier/better for everyone if the issues are written down.

One of the main unfinished aspects of the design was the storm room…  It was just a rough sketch when I got to the architect, not modeled up nearly as well as other aspects of my design.  The architects put in a place holder design when we got started, but never got around to focusing on that area, even to their own satisfaction.   Functionally, the tower is really a solar chimney for the house, but I also wanted to be able to sit up there with a 360 degree view and watch the storms roll over.  It didn’t need to be a big room, but I wanted a hole in the floor to let light down into the rotunda below.  I didn’t want to run the stairs thru the hole because it would clutter the rotunda (originally designed as a central hub of my home) and block the light.  We moved the spiral stair outside the rotunda, but the storm room was two small to run the spiral all the way up into the room.  As a work around, my early design (going in to meet the architect) had involved a switch from spiral to alternating tread stairs part way up.   However, when I saw they way the architects drew it (the shifted the alternating tread stair quite a distance from the spiral), I didn’t like how discontinuous it was and started to consider running the spiral stairs all the way up.  This would not be easy because the storm room is centered over the rotunda (not centered over the stairs) with a radius that doesn’t quite reach the stairs.  Running the spiral stairs all the way up would either require a much larger radius or changing the shape of the storm room (round to egg shaped or with a bump-out) so the stairs will fit.  A week or two ago, Sherri and I re-evaluated our needs and decided to go back to the alternating tread stairs, but try again to get the architects to start them at the top of the spiral stairs so they would be more continuous.  I sent that to the architects, no response yet.  If this last paragraph seemed like a lot of back and forth, that is just how it felt in real life, but stretched over 6 months.  I am interested to see how the story ends.

This drawing is a work in progress with a number of features missing and changes to be made… However, it does illustrate why I can’t just continue the spiral up to the tower… You may also get the hint that we are not exactly going for the simplest earth sheltered design we could think of…

As for the engineer, I have not seen anything yet, although I have asked about it.  At one point, well over a month ago, he had done some preliminary calculations on some of the required reinforcement and determined that “it works”.  A few weeks ago, I summarized a list of half a dozen questions I have asked the engineer over the past few months, but none have been answered.  I guess we would be pretty silly to pay another bill without seeing some of what we have already paid for.  I am hoping something will come thru any day now.

Sourcing

Not much in going on here lately.  I got some quotes on doors.  Sherri is working on getting us an address.  We never heard back from that plumber Sherri mentioned in her earlier post.  I called him after a month, he admitted he hadn’t started yet, but said he would take care of it within a day or so.  I have not heard from him since.  I am working with Pella directly on windows pricing…

Website

The website is now past 3000 visitors   It is getting interesting as I am getting real messages and even email at my “simon@homeintheearth.com” address.  I am getting mail from across the USA and as far away as India.  I added a hit map on the right hand side of the screen to track it.  The free version only tracks 30 days worth of hits, and only collects the data under certain circumstances (shows fewer hits than Google Analytics), but seeing things on a map like that is very interesting.

This past month, I got comments and e-mail from Adam Bearup, somewhat famous to me because of his “earth shelter project Michigan” videos on Vimeo.   The best video is this one about shotcrete…(watch it if you want to get an idea of how our cement will be applied)  We sent some mails back and forth about his experience with earth tubes and I added a bit more info to that section of the site.

I also updated the soil temperature experiment (the temp 10 ft under my property is quite comfortable at this time of year after soaking up heat all summer) and some of the ventilation stuff.

Of course, I still don’t think my site is anywhere near ready…  I want to add info on structures, systems (heating, water, electrical), waterproofing (beyond what is already in the umbrella section), etc.  At some point, the site will be “good enough” and I will mention it on Facebook,  Twitter, etc. and use my Google coupon to to spread the info further than that.  Of course, that will all probably be much closer to the start of construction and the journal part should get more interesting.

Personal

This week, I have my first test in my Cost Accounting MBA class…  I had already used many of these methods in estimating the cost of my home, but it is good to see things defined and and my methods verified.  Maybe I will add a section to the site about that.  But first, I study.

So, now we had bought the land, but it was somewhat backwards from what we had been looking for, at least in terms of driveway direction and the direction towards the best view.  We needed to roughly site the home on the property and make any internal layout adjustment that arose from that.

One rough site plan showing access from the road. We tried several versions of this, including one that separated the garage into two parts, but they all had some key flaws.  The yellow box is roughly the flat area at the top of the hill.

Our property did have a road to the north, actually the road wraps around the north and west of our lot.  I called the county about getting a driveway permit and was able to get agreement that there is a point on the north side with enough sight line distance (for safety, they want 300 feet of view up and down the road from the driveway exit, which is tricky on a curvy road like that) to qualify for a driveway permit.  I also checked with the neighborhood association and they didn’t mind if my driveway came off the road instead of the circle.

However, the best spot to site the home is the flat spot on the top of the hill on the south side of the lot.  A driveway stretching from the acceptable driveway location on the north side would be longer, steeper and curvier, and would therefore need a driveway circle so guests could easily leave (an important design consideration ;))    It would also cost much more to put in and maintain the longer driveway.  Also, thinking passive solar, a driveway on the north side of a house does not have the benefit of winter sunshine to help melt away the snow.  Our particular lot has prevailing winds from the south west; the house would shield the driveway from these winds, and possibly even sweep snow off the roof and onto the driveway.  I really do not like shoveling snow ;).   But the biggest kicker is that our back yard would be on the south side of the house, which, on this lot, is too sunny with no shade and is overlooked by our nearest neighbor.   We enjoy our backyard BBQs all summer and this wouldn’t work for us.

Rough site plan showing driveway from the south, and associated benefits.  The yellow box is roughly the flat “build-able” area at the top of the hill.

On the other hand, if we accepted the fact that things were different than we planned, and swapped the driveway around to the south side of the house, we had a lot of advantages.  The shorter, straighter, flatter, simpler drive way would be easier and cheaper to build and maintain.  The winter sun and wind would help clear the snow.  The back yard would be more private and reserved for plants and play.  Our summer BBQs would be sheltered from the wind and sun.

One problem with this design is that we would need to face the garage somewhat towards the road which may cause friction with the neighborhood association; I was at least able to angle it a little so it wouldn’t face the actual circle (not shown in this rough site plan, but corrected later).  Maybe we could also use trees along the leeward side (East side) of the driveway to hide the garage?

The big problem with switching to the southern driveway was that it required so much change in the house layout.  The front door would need to move from the north side to the south-west corner and this changed a lot of what happened in between.  It shifted the guest suite, my office, the kitchen and dining room, which changed the actual structure of the house.  The main non-structural purpose of the “rotunda” room at the center of the house was a traffic spine from the entry…  That doesn’t work if there is no entry connected to it.  We kicked around a few ideas to try and wrap the driveway from the south side around to the entry cottage on the north side, but none of that worked.   After spending so long to get to that point in the layout, changing it seemed overwhelming and I just didn’t do anything for 4 months (except focus on my MBA, which is a lot of work and not recommended to be done in conjunction with home design or construction).

Anyway, fast forward to this past January 2012.  I took a semester off my MBA and focused on resolving the layout issues and other engineering difficulties…

The start of the room shift… I like how I dumped the chairs on the lawn and the kitchen appliances are in the garage…

The first thing we did was move the entry into the south west pod where the dining room had been.  This meant we had to shift the dining room clockwise into where the kitchen had been and shift the kitchen around to where the mud room, pantry and office had been…  We also took the guest room (previously on the north side of the house as part of the entry cottage) and shoehorned it into the remaining part of the circle, just past the kitchen…  The guest bath ended up on the north side of the rotunda…   Sounds easy… but none of it fit well…  And now I had no office or pantry.

We messed around trying different things for weeks until I ended up increasing the radius of the dining room and kitchen.  This gave us room around the dining room table and let the table be enough out of the way to get from the kitchen to the other rooms.  It also solved the problem of access to the back yard from the kitchen.  Technically, the guest room was in the way, but the relatively larger radius for the kitchen meant we could pass thru the mud room to the north side of the house.   However, this radius increase started the cycle of increasing the square footage again…  We would need to keep an eye on that this time.

We also discovered that the building code used in Michigan would not allow the tight spiral stair I planned to put in the rotunda.  I had got the narrower dimensions from “The Iron Shop” which has advertised in every Popular Science magazine I got for years…  I guess they also provide smaller spirals for people who are not so concerned about building codes.   The larger “min” size specified by the code would not allow much traffic flow in the rotunda, so I decided to move that off to the west (outside the rotunda, behind the wall behind piano), and use up the tight end of the kitchen (where I had briefly placed the pantry, so that was bumped again).  It still didn’t fit well because the storm room only had a 10ft radius, so I am hoping we figure something out there later.

I really needed an office.   I considered putting it in the guest room and just moving out when we had guests, which is what I do now.  We might end up doing that as a cost cutting measure later on, but for now, I decided to plan for a dedicated office.   Unlike most people who want their home office in a remote corner of the house, I like keeping in touch with what is going on;  as long as I can close the door when I need to.   I also like having a window that lets me see who is coming and going from the house.  This lead me to place an apse outside the dining room wall.  Structurally, this would make it easier (and perhaps cheaper) to fill the area outside the dining room wall.  My earlier dining room design had a lot more windows, but that evening light and heat can be annoying, and it was making it a lot harder to earth cover that side of the house.  The new design just has a high chord window tucked into the end of the vault.  For a door, I decided I wanted to use a sliding bookshelf, like a “well-known-secret” door.  My earth sheltered office would have a little window overlooking the driveway and the path to the front door.

Next issue… the guest quarters… interestingly and coincidentally, this took up about a “quarter” of the circle.  We sometimes have multiple guests at a time, or at least parents and their children, so we decided to have two rooms.  They needed to be near and attached to the guest bath that would also serve the main “entertaining” area of the house.  initially, we also wanted the guests to be able to come and go without going thru the main areas of the house and thought it would be good to have a hall from the mud-room to the rotunda.  Now, how to shuffle it to fit nicely?  Try as I might, I just couldn’t make it all fit.  In some cases, I also tried to fit a curved stair around the outside of the rotunda.    We tried a bunch of different combinations, each time we would try fitting a queen size bed in the room and fixtures in the bath room and then imagine using the space (never mind figuring out the roof structure).

We tried a variety of guest quarter layouts. Early versions included a hall from the mud room the the rotunda that was later dropped from the requirements. We couldn’t make it work until we added 2 feet to the radius… Is that the easy way out?

At about this point, I was also researching soil properties and discovered that my particular sandy loam soil had a lateral loading of less than half of clay…  In practical terms, this meant that I could have a basement (and not worry that it needed to be super strong to support the earth forces)… I thought that might be handy under the northern 2/3rds of the circle, but this added a stair requirement, and the stairs should probably connect to the mud room attached to the garage…   This put an additional squeeze on the guest room and killed the hallway idea.

As with many great ideas, the winning idea came to me in the shower one morning…  The radius was just too tight, if I could increase the radius by two feet, I could get a good solution.   This would have a bathroom with a door to one of the rooms.  The other room would act as the guest living room, but could also include sleeping sofas if necessary.  I even thought I could put a large format picture on the wall that could fold out into a bunk…  Lets see if that ever materializes.

Quonset Huts are strong, easy to assemble and very affordable, steel buildings.

The next step was figuring out the roof structure, including the eyebrows, reinforcement, etc., which I will eventually discuss in a TECH Notes post.  I also had basement egress to worry about (extra tricky in an earth sheltered home).  I got some good ideas for that from a Malcolm Wells book (an underground Frank Llyod Wright).  At some point, I don’t remember when, I changed the garage structure to a cement and earth covered Quonset hut…  These steel forms are cheap (30’x40′ garage for $7K) and strong and take all the risk out of shotcrete.  We briefly considered scrapping the previous design and going with a series of these Quonset huts, but we decided we were not that “modern”.   Now we may end up changing from a Q-type Quonset hut to an S-type which has more head room for the garage doors.

By April 2012, I had pushed the limit of what I could get out of Revit…  Making the complex roof structure might have been possible, but not without committing more time to develop skills, and then a lot of evenings to get the work done.  We also knew that we faced an upcoming approval gauntlet with both our lender and our neighborhood association.  We decided to hire a proper architect to help us finish the work…  We also needed an engineer to approve the structural plans.  Going with these professionals would cost us some money, but would smooth the whole process from there…  Heck, they may even be able to improve the layout or other ideas of the house.  More on that stage later.  In the mean time, here is a gallery of my sketches and 3D models…