Building An Earthship In Darfield, B.C.

We are a family of five living in Darfield, BC.
Our house is six hundred square feet in total and we are feeling cramped.

We have decided to build an earthship!

So starts the adventure ...

Saturday, January 31, 2009

Mission Earthship

I've been struggling lately with how to best describe our "mission" for our earthship. It involves a lot of what can be "preachy" topics, and having formerly been a miss-goody-two-shoes--Chris wants to edit "formerly" from this sentence-- I still find it difficult to soften my delivery so we don't appear to ooze self righteousness.

Building an earthship naturally leads to topics such as frugality vs cheapness; recycling vs wastefulness; want vs. need and thinking about the natural world around us and the limited resources the people of this planet actually have. See? Already I can see readers cringing. Usually a discussion about these topics leads to the eventual statement, "well, I will NOT do without my ________". Until a person starts examining these issues in their lives, with an open and honest mind, it is very difficult not to react defensively. I know. Chris led the way in this thinking and had to very patiently wait for me to catch up. Over the last several years I made a lot of statements with capitalized NOTs in them! It's incredibly difficult to let go of conventional thinking...

For both of us our changes were fairly private until last fall when we started this blog. While we were comfortable with our decisions, we knew that our plans were unusual, certainly for our wider circle of friends and family, but even for the general North American population. Despite the direction we are taking, we are after all, fairly normal people who do wonder occassionally what the chatter is among our friends and family when we are not around! Being fairly appreciative of wit in ourselves and others, we recognize the intensely rich fodder for well intentioned chiding and jokes!

In the end, our desire to share our journey outweighed the lack of privacy. After all we have never let opinion change our decisions. Our journey started with us walking away from two highly paid professional jobs in major North American cities more than a decade ago, and starting a log home business. That alone I think set the stage for more unexpected changes.

But I digress, and my journalism profs would shudder; I've buried the lead! We have several fairly concrete aims for our earthship, all of which will lead to discussions of frugaility, wastefullness, fullfilment and probably many other topics we never expected to face. But for now let's start with the concrete goals:

1) To build ourselves a house that is as sustainable as can fit our needs.

2) To build ourselves a house that is within the financial reach of ANYBODY. We want to prove that a family home does not have to tie somebody to a mortgage. To that end I will be tracking our expenditures and posting them on this blog. I'm sure it will be an eye opener for me, as well!

3) To build ourselves a house that uses as much recycled and re-used material as possible.

4) To build ourselves a house. We want to do as much of the work ourselves. Although Chris is an engineer, and we have some practical experience building houses, we do not consider ourselves terribly more experienced than most people.

5) To include and educate our community-in both the local and more global sense -- in building our home. Part of this is committing to updating the blog regularly. We will talk about our other community plans as things progress!

Thursday, January 22, 2009

Investigating Graywater

I’ve spent the last couple of days trying to wrap my head around the implementation of a gray water recovery system for the earthship. The information provided in the Earthship volumes by Mike Reynolds is not detailed, and as gray water recovery is not a common building practice it is difficult to find information on this topic.

First a bit of background … Fresh water (from a well or rainwater cache) is degraded after it is used residentially; it becomes either black or gray water. Black water refers to the outflow from toilets, which contains fecal matter and is difficult to treat. Gray water is the outflow from the remaining plumbing fixtures in the house; sinks, showers, baths and laundry. This water is easier to treat and it is this water that we will be recovering in our gray water recovery system.

From my initial research the regulatory work done on gray water systems in Canada is only at beginning stages, and deals mostly with the recovery of gray water for later use in flushing toilets. This model of gray water recovery stresses the chlorination/treatment of the gray water so that it can be stored for later use. This is an expensive process requiring chemicals, storage and pumping that is not what we are interested in. Our intention is to contain, filter and then use the gray water in a constructed wetland environment located in our residence. The gray water will be purified in this environment and used to grow plants and fruit trees. This basic approach is described in Earthship Volume 3, but as I said earlier, the implementation details are vague.

In Canada the CHMC (Canadian Housing and Mortgage Corporation) is doing some research into gray water systems, and seems to be involved in defining standards. Cate Soroczan is listed as the Project Manager on much of this work and would seem to be a useful contact. I intend to start with the CHMC to determine what regulations govern the implementation of a gray water system in our jurisdiction and what standards exist.

My other approach to investigating gray water was to try and determine generally accepted construction methods and practices with regard to gray water recovery. As gray water recovery is not used in mainstream North American construction there seem to be a lot of conflicting opinions and practices in this field. The work of Art Ludwig is referenced often on the internet by various organizations (The Real Goods for one) and people, and as it turns out he has two books out on the subject; ‘Create an Oasis with Gray Water’ and the ‘Builder’s Gray water Guide’. I have decided to pin my hopes on Art Ludwig’s experience and have ordered these two books ( Hopefully, when these two books arrive I can start laying out a gray water recovery system in earnest.

In the meantime I think I have tracked down enough information to flesh out the square footage and basic layout required of a gray water system for my family of five. This should allow me to carry on with drawing my plans and ensuring that I have allocated enough space for gray water recovery and located the system logically in our home. The initial information on gray water that I will be using in my design is 35 gallons per day / per person of gray water generated residentially, and from .14 – 1.2 sqft of gray water ‘mulch field’ per gallon of gray water generated per day.

In other words, my family of five will generate 175 gallons of gray water per day, and the gray water field will need to be 24.5 sqft on the low side to 210 sqft on the high side. For the time being I am going to stick to the upper end of this estimate and design a gray water field of approximately 200 sqft. With this information in mind I have modified my plans as detailed in the attached drawing. I will modify them again as I learn more about gray water.

Most of the changes in this iteration of the plans are based on layout and our ultimate preferences. We re-arranged the kitchen and pantry for better work flow. Sandra wanted easy access to the outside from the kitchen so we added a vestibule and door in the middle. We have added a second toilet so that we are not all lined up to use the bathroom. I cannot easily figure out how to move the second bathroom closer to the master bedroom given the constraints imposed by the water system. Sandra and I have agreed we can live with this layout.

Wednesday, January 14, 2009

Floor Insulation; to insulate or not ... that is the question!

This is a hot topic ... people have been weighing in both for and against floor insulation by email and on the blog. In fact you might even say the discussion has been heated ... alright I'm going to drop the puns from this point forward!

As near as I can make out the basic earthship design has evolved somewhat since the publication of Michael Reynold's third earthship book, and some of the newer design details do not seem to be readily available (unless I have missed them in my reading).

In his newer work Mike Reynolds refers to a thermal wrap around the earthship and it took a fair bit of digging (I can't help it) to find out what this thermal wrap is. It turns out the thermal wrap is a layer of rigid insulation placed around the bermed walls of the earthship after an initial backfill of the walls has been done.

I am assuming the point of this thermal wrap is to increase the amount of insulated mass attached to the earthship, and consequently to increase the efficiency of the 'thermal battery' that is the basis of the earthship design.

I have upgraded my initial drawing and include a cross section view of this whole idea at the top of this article. I believe that this thermal wrap is supposed to address issues that the earthship design has had in colder climates, specifically that it did not retain enough heat during the winter, and thus was not successful in regulating its temperature. Also, I have read complaints that despite a given earthship staying warm enough during the winter months, the floor temperature was simply too cold.

So, on the one side of this argument is the original earthship concept. The basic premise of this argument is that the minimum temperature of the earthship should not dip lower than about 55 degrees F (stable earth temperature), and the warming action of the sun during the day should in fact keep that temperature in an acceptable range of 65-75 degrees F.

On the other side of the argument are the reported failures of the earthship design in cold weather climates. Reading between the lines I think the failure of the design stems from the ground under and to the north of the earthship still being affected by seasonal temperatures. In other words, the ground under the earthship settles out somewhere between stable earth temperature and a value above freezing. I suspect this failure is also tied to quality of winter sun in various regions. We live in a valley and I have some concerns about the amount of sun we get in December.

So where do I weigh in on this entire argument ...

I have now been in an earthship in Ontario on December 20th (2nd shortest day of the year) and it was -20 degrees C outside. The inside temperature was about 65 degrees F and the only additional heat was provided by a wood cook stove when food was being cooked. The basic premise that the earthship should maintain a reasonable and consistent temperature was being met. The floor in this earthship was not insulated, and the builder agrees with Micheal Reynolds that the floor should NOT be insulated.

I have to admit, although not intolerable, I did find the floor cooler than I would have liked. I tend to agree with the basic statement that an uninsulated floor is going to be cooler than your desirable room temperature of say 20 degrees C simply because stable earth temperature is below this temperature. It seems to follow that in a colder winter climate the floor will be that much colder than desired room temperature.

I intend on having a backup heating system in my house. I am actually in favour of radiant heat as opposed to direct wood heat, and I would prefer a warm floor. It would be possible to run the radiant heat in the tire walls and/or the floor. I do not see any need to insulate or heat the floor under the planters and a few other locations. Beyond this I have not come to any conclusions.

Saturday, January 10, 2009

Our visit to the Potter Earthship near Gilmour, Ontario

The initial 30 seconds of our visit to the Potters was not auspicious; Pat Potter was a little taken aback—and I detected a little irritated—that I had maneuvered up the second half of her driveway after she cautioned us earlier in the day about a possible icy base on the road.

I think she had some basis for worry; apparently she once had an accident on the icy part that resulted in some pricey dental repairs.

Nevertheless, having driven for more 25 years on B.C. mountain roads, some of them very steep and icy, I had no worries about navigating the last few hundred feet of the Potters' drive in our Honda CRV – equipped with brand new winter tires to boot!

Pat and Chuck were very welcoming and we entered their home with bright sunshine streaming through the slanted greenhouse windows. The show belonged to Chris for the ensuing two hours as he literally grilled Chuck and Pat about the technical aspects of building an Earthship.

After two hours I asked Chris, “Are you finished yet? I’d like to take the tour, now!”

The Potters’ Earthship is not finished. By their own admission, the last five years have been filled with their environmental activism. Having worked non-stop in our small business for the better part of 10 years, I can relate to how “home finishing” often takes a back seat to other aspects of life. Nonetheless, Pat’s office, at one end of the building, was finished beautifully, sporting a lovely sculpted yellow sun on the back wall. The greenhouse/planter in this room comprised lovely trailing plants. For the first time I could imagine how our house might look.

I also very much liked how Chuck and Pat sculpted in photo alcoves in the walls to display photos or treasured knickknacks. I brought my camera, intending to ask permission to take a few pictures for our blog, but Pat mentioned that they began prohibiting photo taking after they discovered a reproduction of a photo of Chuck that appeared in Ripleys!

The air temperature in the house was quite comfortable at the beginning of our visit with the sun streaming in. It was -20 C outside. As the sun set, I did notice that I began to feel colder, but I noticed that Pat was rarely feeding the woodstove. I felt that whatever auxiliary heating system we installed, we could keep our home at a comfortable heat during winter.

Almost as interesting to me during our visit was Pat and Chuck’s story of environmental activism. In an age of apathy and mediocrity, Pat and Chuck certainly stand out without apology in their passion for the environment. Their Earthship is only one aspect of what they feel they need to be doing for the earth.

Three hours and $60 later (after 7,000 visitors, Pat and Chuck now charge for their time), we left assuring Pat we would call from the cell phone when we successfully navigated the driveway on the way out.

Our visit certainly reassured us that we are capable of taking on an Earthship building project, and made us quite excited about how we will personalize our design to make it our own.

Friday, January 9, 2009

We Visited the Potter Earthship (Chris' take)

On December 15th we started our Christmas holidays!

In the next four days we traveled halfway across the country (4300km) to visit my family for Christmas. We averaged 1000 kilometres a day and the relief in the car was obvious by the time we pulled into Portland, Ontario! The kids are excited about visiting the CN tower the following weekend, but my excitement was our planned visit to the Potters the next day.

Knowing that we were heading to Ontario we decided to look into the Potter’s earthship. The Potters built an earthship about ten years ago just outside of Bancroft Ontario. We found out about it on the web at, and found out that they will give tours of their home if you arrange to visit them in advance.

That was enough for us!!! Before we left BC we phoned the Potters and arranged to visit them and their house on the 20th of December, the day after we arrived in Ontario. The weather as we traveled across the country was pretty good; no new snow and reasonable roads. Literally within an hour of arriving at my parent’s house it started snowing, and was still snowing when we went to bed.

Fortunately the morning of the 20th the sky was clear and we slowly made our way to the Potter’s earthship. Despite all of the research we have done preparing to build our earthship we had not yet actually set foot in one, so both Sandra and I were looking forward to seeing this house.

When we arrived Chuck and Pat Potter met us at the door and we all sat down at their kitchen table. We talked to them for a couple of hours and the conversation alone was worth the visit. The discussion ranged from gray water recovery to permitting the building to the nuts and bolts of tire pounding.

The Potters built their home over three years and were the actual builders of the home. In their words they built the home from cash on hand so they did not have to take on any debt, and they estimate they spent $45,000 dollars on their home. The only down side to building the home this way is that it took them over three years to finish!

Their house is approximately 2500 sqft and built using the methods and layouts described in the first two Earthship volumes. I am not sure if the third volume was written when they built. We visited on the second shortest day of the year; the inside temperature was in the mid-sixties and their only heating source was a wood burning kitchen stove that they use for cooking.

Our discussion covered numerous topics and here is what I remember …

Pounding Tires

The traditional method of filling tires involves a sledgehammer and lots of manual labour. Each tire is filled with earth and literally beaten with a sledge hammer until 95% compaction is achieved. I had researched a method of tire pounding that involves cutting the top sidewall off of the tire after it is placed in the wall. The removal of the sidewall allows the tire to be easily compacted with minimal effort. The Potters cautioned against this method as the removal of the sidewall means that the tires will not bulge as they are filled. The bulging tires actually interlock with each other such that a tire cannot be pulled out of a finished wall. The Potters also said that the initial engineering analysis done on these walls in New Mexico was very complementary of this interlocked stack of tires and said that it was structurally sound and made the tire wall very resistant to lateral forces. Cutting the tops off of the tires minimizes this interlocking and reduces the structural integrity of the wall. It looks like we will be pounding tires the hard way!

Floor Insulation

There is a lot of debate about the use of insulation under the floor of an earthship. The Earthship books written by Mike Reynolds are pretty clear that you do not place insulation between the earthship and the ground beneath it. The earthship relies on the constant temperature provided by the mass of earth underneath it, and insulation cuts the earthship off from this ‘thermal battery’. There is some discussion in Canada that due to the colder climate insulation should be used. Chuck Potter was very emphatic on this point … do not place insulation between the building and the ground. I agree with this.

This lack of floor insulation can result in cold floors. We discussed the use of a radiant floor heating system (or radiant wall) to resolve this issue. This is something I would like to investigate more.

Wall Finishes

The Potters originally planned to use stucco on their walls. They wound up using a cement/sand mixture. They felt that stucco would require more maintenance over time. They are quite happy with this wall finish. They used cistern paint on the interior walls as this paint also provides the vapour barrier.

South Facing Windows

The Potters have never installed blinds on their windows. They estimate they lose 5-10 degrees of warmth overnight.

This covers off what I remember talking about. I will add more details to this post if and when I think of other things.