Vertical glass vs. sloped glass earthship design

I was wondering why you chose to have vertical windows on the front face rather than angled - building code difficulty or construction problem? Does the greenhouse area get cold at night in the winter?

We chose vertical glass because of the heat. Sloped glass ships (SG) get significantly more sun, year round, than vertical glass (VG) ships. And the sun is HOT, my friend. Very very hot. In fact, the sun is so hot here at our latitude that if I had it to do over, I would have gone for a westerly facing angle instead of due south. In southern Virginia, cold is not the challenge; heat is the challenge. Summer night lows can be as high as 80 in our neck of the woods, so the concept of convection cooling at night just does not apply. Ships located in the western desert can rely on convection cooling since the nighttime lows (even in summer) can hover closer to 60.

The other thing we've done to deal with the heat is separate the greenhouse from the living space with exterior grade sliding glass doors. The greenhouse gets as hot as the outside in summer (90+ sometimes), but only as cold as 55 or 60 in the winter. We open and close the greenhouse doors as needed to adjust the temperature. This is especially useful in the winter, when the greenhouse will heat up to a balmy 85. We open the doors and the house is flooded with warm air. The greenhouse, even though we have lots of below freezing nights, does not go below 55 in the winter. We grow tropical plants like lime and lemon grass in our greenhouse. In the summer, we keep the doors closed so the heat stays in the greenhouse and out of the house. We also have a commercial grade greenhouse ventilation fan. Without the fan, the greenhouse is upwards of 100 on a sunny day, even in winter!

Earthship green roof at 6 months

We planted the roof in October of 2007 with over 1,000 seedum plugs. We watered with a soaker hose for a while, but the plants didn't look so great. We switched to a sprinkler and that did the trick. We also applied Miracle Grow when the weather warmed up. They really took off. I spend about 1 hour a week weeding it. Theoretically, once it grows in thick it won't need weeding.

The plants feel like animals, like creatures, more than they feel like plants. Seedums have a rubbery texture. Gabriel says being on the roof is like being underwater. The kids have named the plants things like "squidy" and "octy."

Earthship construction slideshow

We built our earthship out of ICF (insulated concrete forms). We could not get approval from our local government officials for earth rammed tires.

This slide show includes the initial building process and various improvement projects we've done/are doing.

Earthship planter transpires all the greywater you can give it!

Greywater is non-septic wastewater from your home. Examples of greywater are: shower water, dishwasher water, clothes washer water, etc. In our home, all our greywater is directed to this planter, located in the greenhouse. The planter is 80 square feet and the plants transpire 100% of our wastewater. We no longer track our water consumption, but historical data shows our daily consumption at 12 gallons per day per person. On average, we release 60 gallons a day to our plants and they drink all of it. Growing in our planter are palms, ficus, umbrella, rubber, pothos, aloe, and a lime tree.

Earthship grows food year round in greenhouse

Gratitude to Mother Pat for helping my thumb turn green. These plants originally came from my summer garden. I never harvested any tomatoes from my summer garden due to tomato horn worms. Big green suckers. The only reason I have any plants at all is because Mother Pat, my botanist neighbor, came over one day and plucked all the horn worms off. There were 35 of them, give or take a handful. Chickens love horn worms.

Mother Pat was then good enough to explain to me how I can overwinter my tomatoes in the greenhouse:

• take a healthy looking cutting as long as your elbow to your finger tips
• bury it in a pot so that only the top 3" show
• keep it properly watered
• feed it regularly
• supplement with Epsom salt

I followed these instructions and got a beautiful harvest.

Earthship power usage Feb 2008: 1044 kWh

We've been running our electric heat since our firewood is too wet this year, and this habit is reflected in our power usage this month. Still, we are very close to 1,000 kWh. Also, our housekeeper brings and uses a vacuum cleaner (something we never did before) and that may have increased our usage, too.

Our six month usage history is:

• Feb 2008 1044
• Jan 2008 904
• Dec 2007 642
• Oct 2007 675
• Nov 2007 818
• Sep 2007 1254

Fujitsu multi-split units: effects of use on power consumption

How much energy do Fujitsu multi-split units use in a real-life setting? Apparently, not very much. Our last 30 days of power use was 642 kWh and we used our Fujitsu multi-split units for heating our 1,600 SF interior . The heat they provided was dry and warm, not like heat-pump heat I have experienced in the past.

We never planned to have electric heat. We have Bert, our wood stove, who does duty as a heater, light source, marshmallow toaster, home scent diffuser, and soil additive manufacturer. As with most people living in a bermed home, we noticed that the winter temperature rose dramatically in the first three years, settling out to an unheated dawn temperature of 17(63). The first winters saw lower temps, more like 14(57). So Bert's job duties shifted from being significant heat source to chasing off the damp chill of a mild Southern winter. Whatever we wanted to use Bert for, Bert ate wood.

On a very wet cold day, we would go through 10 pieces of wood in a 24 hour period. Usually, we would light a fire 3, maybe 4, times a week at most. Remember, a sunny day brings the temperature in our house up to a balmy 25(77). A cord of wood lasts us about 3 years. Firewood needs to age in order to catch quickly. Aged too much, it is called mulch. Aged not enough, it is called why-won't-this-fucking-fire-start. The trick to properly aging firewood is a tarp that covers the top and protects the wood from water and sun. No tarp, and in a short 18 months you'll have a wood-pile shaped lump of mulch and bugs. Fresh wood won't start. We've found that wood needs 1 year to start with aggressive assistance. At two years, it will start with little assistance. At the three year mark you can light it, literally, with a match.

This year, we have a cord of fresh wood. The why-won't-this-fucking-fire start kind, seeing as it was cut down about 8 weeks ago. We used the old logs as starter logs, and by putting the new wood onto a bed of glowing coals even the greenest of logs could not refuse to ignite. We used up the last bits of match-light firewood last month. And being low-work people, have not really had a fire since.

A lightening strike took out our old A/C only unit a few months ago. That unit is no longer maid, and the new model included a heating function. There is one outdoor unit and three indoor units: one in the main room, one in the kids' area, and one in our bedroom. We are using them separately for a few hours each day. First thing in the morning, the temperature is a perfect 21(70) in the great room, but feels damp and chilly. We've noticed that temperature alone is not a good way of measuring how cold it feels. Humidity and pressure play a mysterious role perception of "cold."

The splits let us decide where and when to apply heat. This morning, I have the great room unit on, and nothing else. I will turn it off around 10, when the greenhouse is warming up. In the evening, I'll turn on the ones in the bedrooms for 2 hours, and then shut them off when we go to sleep. This level of electric heating has not significantly increased our power consumption. Isn't that weird?

Last month, we used 675kWh. This month, with the addition of the splits, we used 642kWh. Does this mean the multi splits use less energy to heat our home than our dryer does to dry our clothes? Could a standard house heat itself with so little use of the units? Maybe the energy savings is just a function of the insulation... none of the heat gets out, so we use less of it. It could even be the green roof, or maybe a combination of all of these things. I am looking forward to more data that can help me understand what is going on.

Earthship grows a green roof

It is our understanding that our home is the first Earthship to have a green roof. We still are able to collect rainwater, although the amount collected will reduce as the plants mature. In the first 3 days after installation, it was very warm outside. During those warm days, we did notice a 4 degree temperature drop as result of the roofing material. But then Fall proper came, along with cooler temperatures. We'll have to continue reviewing the roof's impact on interior temperatures next summer.

We hope to see a significant decrease in how much A/C we need to use. There are several layers to a green roof. The first is the rubber membrane the covers the roof decking. Next comes a root barrier cloth. On top of that is green fabric that retains water on one side (the top) and allows water to drain on the other (the bottom). Once that is in place, the hummus and shale growing medium is shoveled on. Lastly, the plugs are planted into the growing medium. It will take a season or two or three for our roof to change color, but you can see the 1,000 or so plugs of various seedum plants in the growing medium.

Dealing with southern summer heat in an earthship

Our ship, without A/C is bloody HOT. We have had temperatures over 100 degrees. Our particular construction has some flaws that increase the heat: black roof and limited attic-space insulation. Apparently though, ships built in the traditional manner also have summer over-heating issues. We've been in contact with other shippers who also report excessively high temperatures in the summer.

To deal with the heat, we started with reflective coating on the glass in the greenhouse. That did nothing for the temperatures. Then we installed a green house exhaust fan. That reduced the greenhouse temperature to no hotter than it was outside any given day. Before the fan, the greenhouse regularly got up to 120 degrees. We had spider mites, dying plants, and a very stuffy space until the fan was installed. Still, the inside temperature was reaching 100 on a regular basis. Next was shade.

We installed dark curtains to keep the sun out of the main house. This had a slight effect, bringing the interior temperatures down into the high 90's. We were still sweltering most of the time. Finally, we installed A/C. It was a difficult decision and felt like a failure at first.

We opted for low power use units, called Multi Splits, rather than central air. Our A/C is excellent at reducing humidity and the stickiness is more uncomfortable than the heat. Our A/C can effectively reduce the heat by 10 degrees, no more. So, on the hottest 100 degree summer days, the house gets up into the high 80's but is not at all humid. As soon as the sun sets, the house gets comfortable again. We've discovered that anything under 80 is comfortable. Over 80 and we all get... stinky and sticky. But only for a few hours each day.

Earthship digging of a shallow well

Before drilling begins, a series of connected shallow pits are dug. While the drill bores into the ground, water is flushed into the hole to keep it free of debris. The excess water is channeled through the pre-dug trenches and is sucked up by a huge sump-pump and drained away from the work area. The whole process takes three days: one to set up, one to drill and dig a trench to the house, and one for hooking up to the electricity and the main water line.

Earthship switches to a shallow well for drinking water

Can you hear that? Neither can we. What we cannot hear is the noise of the pressure tank and motor. The pressure tank and motor used to be inside the house, in the utility area. We dared not flush in the night for fear of walking up our young son. For the last few nights we've been night-flushing with reckless abandon. The other thing we do not hear is the sound of our power meter spinning so much; the shallow well uses far less electricity than our rainwater harvesting system did.

We eliminated a sand filer (this could also have been eliminated with black tanks, but a circulation pump is necessary either way), 2 in-line filters, and a UV light. Overall, we feel we are getting better water (no chemical drift from fertilized crops next door) with a smaller carbon footprint. If we had it to do over... I would probably get a shallow well to begin with and structure the house for a 9-12" sod roof. Rainwater collection for use as potable water was too complicated for our application and did not address water safety to my satisfaction. Collecting rainwater for irrigation is viable and works for us. If the health department was not insistent on potable water being in the toilets, I would use rainwater for flushing. But according to our codes, ALL exposed water (even the stuff in the bowl) must be drinkable.

Earthship switches to well water from rainwater for potable water needs

It is with some sadness that we prepare to say goodbye to our rainwater harvesting system. When giving tours, the highlight has always been the water tanks. Knowing that our water came from the sky was lovely. Overall, we were emotionally attached to rainwater because it is just so... so cool! But it is not the best choice for our site.

In order to make rainwater work for us, we had to jump through a lot of hoops. Those hoops have became burdens in both cost and energy and we are relived to be offloading them. In balancing out the other pieces of the equation, our site is not well-suited for rainwater harvesting. This decision took several years to make, and is based on the following:

Our existent tanks promote algae growth. Our transparent, above-ground tanks were the wrong tanks for the job. We should have used black or completely buried tanks to prevent rampant algae growth. We installed a sand filter to deal with the algae problem, but the plumbing and maintenance was complex. Additionally, the sand filter uses a 1 HP motor that runs all time time. We could not justify the power consumption.

There is commercial farming right next to us. The plat that directly abuts our property is a commercial soy and cotton field. This field is sprayed with all manner of chemicals during the growing season. This spray floats to our roof and gets washed into our tanks. We drink distilled water anyway, but I do not like the idea of water that is seasoned with poison.

Filters are cost-prohibitive both in dollars and in carbon-load. Rainwater stored in tanks requires filtration if used for human consumption. The minimum set up would be a .5 micron particle filter (the white ones that look like string) and a carbon filter. These filters are made of plastic and virgin materials They are readily available in our area, provided I don't mind shopping at Wal-Mart. Filters ran us about $20 a month and were made out of plastic. A well will not require particle filtration. We could use a carbon filter for taste (the well water around here can be funky), but since we are using only distilled water for drinking and cooking we will be able to eliminate filters altogether.

UV disinfection is not an energy cost we can justify. We use a UV light to disinfect our water. This light is on 24/7. Well water does not require disinfection.

We need a different type of roof to deal with the heat. Before we installed A/C, we had interior temperatures of over 100 on the hottest days. There are many reasons for this that are outside the scope of this post. The pertinent one is lack of insulation. Our contractor did not build the roof according to the plans we provided him, and we are missing a crucial 24" of insulation. Plus he used black EPDM instead of white. At this point, we are considering installing a sod roof to resolve this issue, and sod would preclude rainwater collection. Sod would provide excellent insulation and heat deflection.

As you contemplate your household water source options, consider issues like chemical drift onto your roof, feasibility of installing buried collection tanks, energy cost and monetary cost of filtration, disinfection requirements, and simplicity.

How much does it cost to build an earthship?

In a nutshell, the construction of our home did not cost more than the construction of a standard stick-built house of the same size. We built our earthship for $140,000 in 2005. This number includes the basic rectangular structure, the greenhouse (with a dirt floor), our rainwater tanks, the berm, and appliances.

Our interior was roughed in, but not finished. One of the ways we kept costs very low was by not having a standard kitchen with cabinets above and below countertops. Our kitchen has no wall cabinets. All the pieces (island, sink, prep area, dishwasher) are free standing, like in a commercial kitchen. We used off the shelf items, built out of concrete (not tire), and used regular windows instead of cut-to-fit shop glass.

Our ship is 2500 sf and our building costs ran about $60 per square foot. This is about industry standard, maybe a little less, for owner run construction of any type of home. You can expect to pay at least $70 per square foot for a turnkey contractor-built house, earthship or otherwise. In the end, I think we will end up spending $70/sf when we add up all planned improvements.

Rainwater harvesting issues

We had to install a particle filter and a carbon filter to deal with the algae and particles that flowed into the tanks from the roof. Without the filters, the water is green and very gross. There are living things in it that I can see with my naked eye. Yuk. The filters are running us $20/month. Cheaper than city water, but what a pain in the ass. Water quality is a concern for us. Is it safe? What can we do to prevent the grossness, besides for installing a buried tank in the first place? Hindsight is 20/20, and if we had it to do over again we would spring for the expense of a buried water collection tank. The exposure to the sun is a huge problem. I am not even sure if a black tank would have done the trick- the sun is relentless and plastic does not hold up well to UV light, no matter how "treated" it is.

We moved in to our earthship!

The greenhouse floor is unfinished, just raw dirt. We bought 80' of astro-turf and covered it up. The water is green. We are looking into filters. The floor is raw concrete and very dusty. The windows of the front face are not properly sealed and bugs are coming in. There are boxes everywhere. I have no idea where the camera is. We've outsourced the kids for 2 weeks while we get situated. Hopefully, we'll have base camp up and running by the time they get here. Its pretty rough right now.

First order of business is getting the water cleared up. We are going to need a particle filter and an algae filter. Getting the windows weather/bug proof is also pretty high on my list. One thing at a time. I am trying to stay focused on the fun part of this: we are finally living in our Earthship. A bit less than a year in the building. Whew.

Building the planter... twice

We lined the planter bed with pond liner and propped the sides open so they do not collapse as we fill it with gravel. We then filled the planter and it leaked.




We should have tested it for leaks before filling it with 9 tons of rock.
We dug out the rock, covered the pond liner with a sheet of EPDM, and started over. At its deepest point, the planter is almost 3'.

At the end of the line is the exit pipe. This pipe must be placed within a matrix of very large rock. This allows unfettered flow of waste water to our septic tank. In some designs, this water is pumped back to the toilets to use for flushing. In our district, all exposed water must be potable including water used to flush the toilet. To make the planter water potable we would have had to install a RO system, which was energy and cost prohibitive.

After the plumbing was set the the gravel goes in. It took us 23 man hours to complete this task each time. 46 hours total. I am so glad it is done.

Fire in the hole

We fired our contractor today after much consultation with our attorney. He (the contractor) is almost 6 months past his completion date set forth in our contract. Not to mention that he has not been doing the work in a "workmanlike manner." Each interaction was getting more tense and its nice to finally have him gone. When the contractor left the site, the change in energy was palpable. The house is not yet functional and we are scheduled to move in March 1. Most of the remaining work is already sub-contracted out, and then there are hundreds of odd, little jobs that we will finish ourselves.

Installing a French drain

We noticed that our footers were wet a lot. And there was a lot of mud. My grandparents built the home of their dreams in 1950 and had to dig out and re-seal the basement by 1956. In an effort to deflect flood karma, we went ahead and installed a French drain along the West (and wetest) part of the house. It extends half way down the front and then angles off into the center of the yard. When the rocks ran out of the bucket, they sounded just like rain.

Earthship contractor running VERY late

Our contractor assures us that he will be finished by December 1, 2003. We are trying to remain positive that he will be able to finish by then, but the state of the construction leads us to believe there will be more delays. We've left him a little written reminder of his promised completion date.

Earthship framing begins

It finally looks like a house! The contractor is starting to be late and/or not show up, and we are behind schedule. Even so, we are besides ourselves with excitement at this step. We used standard size windows for our front face rather than the recommended cut-to-size shop glass.

The windows were just so much easier and we are really pushing for completion. The greenhouse is starting to take shape with the rafters and roof in place. Its much taller in reality than it was in my mind. There will be room inside for some very tall trees. Gabriel and I take a dip in our claw foot tub.