My Earthship Type Idea-Feedback Please

So I was thinking of making a eartship but instead of tire walls I would just use hempcrete or concrete. Also instead of the whirlybirds or a skylight you can open, i would use some fans to draw out air from the earth tubes and out of the greenhouse area.  HRV would be a must as the eartship seems to have no winter ventilation. Does anyone know of anyone else who has modernized some aspects of the eartship design? I am planning on using a biogas kit(like homebiogas) for cooking and use a lehmens washer and a drying closet but some of the recycling methods just seem way to labor intensive and I'm concerned about the risk of leaks when it comes to the earthships massive skylights and poor air quality in the winter. The eartship off grid aspect is interesting and I too may be offgrid, but I'd like to use less naturalgas/propane if possible by avoiding using a gas oven or gas clothes dryers althought I may use a gas water heater with a solar pv direct heating element because of practicality. Feedback or examples of people who have modified the earthship would be appreciated. I've only seen the Collingwood earthship upgrade the standard designs by using whirlybirds and a HRV.

I'm planning on starting an earthship style house this Spring with pumicecrete walls, rather than tires. They are typically 14-18 inches thick, and consist of a mixture of mostly pumice and a smaller percentage of concrete. There isn't much info to be found on the internet regarding pumicecrete, other than a company out of New Mexico that has used it for years in home building. It has great structural integrity, as well as insulating qualities. I have yet to determine what style of roof I will use-perhaps either a vega or steel beam, supported by 3-4 load bearing walls. I want to use vertical windows in the greenhouse for the main (larger lower) windows, and follow up with some smaller slanted windows above them-as seen in some of the later earthship designs that have appeared in oversea or more tropical regions by Michael Renyolds. The reason for vertical windows is that slanded ones tend to recieve over time more water damage on the interior (from condensation) as well as the exterior from the elements. It also affords me the opportunity to have more greenhouse area for taller plants to grow without bumping and coming into contact with the window. I'll also have a divider wall between the greenhouse area and the living space, and operable windows (3-4 above the lower main windows) as well as skylights in the greenhouse. The load bearing walls will extend from the pumicecrete wall in the back, to the divider wall between the greenhouse and living space. I plan to install a masonary stove or rocket heater that seperates the kitcheon area from the living space, which will all be open. There will be walls separation my bedroom from my studio and also the bathrooms. One nice thing about pumicecrete is that you can route out the walls to string electricial conduit, and either adobe or stucco easity adheres to it for the final coat. I haven't looked into the advantages that hempcrete would have over pumicecrete, but have noticed that there are more books and info available for hempcrete. What timeframe do you have for starting yours?  

Awesome reply dude. Keep us updated when your house starts to be built. On the point of the windows....I always thought that no roof overhang with the angled windows would be a problem with water damage, never thought of the plants having more space to grow vertically though that's a good point. The verticle window portion would also be a lot easier to construct. I like the idea of hempcrete but honestly don't totally trust any construction product that isn't adopted by the mainstream already though. I remember working for a contractor years ago and having him tell people that the plastic pipe for hot water we were installing would never leak unless it was right away. Once it was installed it would last forever. Years later it has been found to corrode pretty rapidly for residential water use, nevermind the in floor heating application we used it for. My timeframe is kindof up in the air....I am moving for sure in the next few years, but I may rent for a while. Definitely within 5 years.

I plan on doing an earthship like house but will be using dry stacked concrete blocks with surface bonding. Supposed to be 6-7 times stronger than mortared block. I'm 53 years old, 125 lbs and cannot do the labor required for tire walls, plus we have very wet soil for half of the year, moss growing on the bases of all trees etc so I worry about water infiltration. I'm going to build on grade and then pile dirt up around it. Even then, I'll need to seal things up well and have plenty of french drains. During the rainy season, I can walk out and see a few little geysers bubbling up out of the ground.

I've got lots of rock on the property so I'm going to build the greenhouse walls out of that. I'm still undecided on whether to slant the glass or not. We get hail here at least once a year and occasionally, baseball sized. I'm building near where the property drops down to a hill. That will allow me to do thermosiphon radiant floor heating using swimming pool type solar collectors. The property also has a grade to the East so that end of the house will be all above grade and transition to an outdoor kitchen.

I had an idea but I don't know how well it would work. Behind the back wall of the rooms, have a 6 foot wide hallway full length of the house. Could do a dirt floor in it and have it lower than the house floor. I don't know if it would stay cool enough for a root cellar. If I insulate the wall between it and the living space it might. Could at least be a pantry though I'd probably want a concrete floor in that case. We do have tornadoes here so it would be a good shelter. Maybe just do it half length of the house. The outdoor kitchen would be up against the indoor kitchen naturally and then the bathroom next to that to keep plumbing all in one spot. I could do the shelter behind the kitchen and bath. Then isolate and insulate 6 foot of soil behind the rest of the house for the thermal mass so that the bedrooms and living room temps stay nice and even.

btw, what is HRV? All I get from a web search is Heart Rate Variation.

Hi John Pollard, glad to hear that you're thinking of an earthship. You could also use pumicecrete blocks for your walls-they would be lighter to handle and likely have better insulating value than concrete block. You could make them by mixing ground pumice with concrete or purchase them. Google pumicecrete and you'll find a company from New Mexico that will give more detail on it's application for building. They are also porous and easy to finish with stucco. I'm going to have a company from New Mexico come up here from New Mexico this summer  (I live in Cotopaxi, Co.) and pour pumicecrete walls for my earthship. I'm going to have vertical windows for the south facing windows, with a row of smaller slanted windows above that will be operable-can open or close. I've found that slanted windows (from staying with friends with earthships) tend to collect condensation-which damages the sills. Vertical windows also give more room in the green house area. Slanted windows would be easier to damage with water (outside rain etc.) and hail. You could opt for fewer slanted (half or so) windows above, and protect those with steel mesh..Good luck and stay in touch.  Stan

Just so I understand where everyone is coming from, what are seen to be the good points of earthships that are being kept or augmented?

For my own part, I need to try to keep my mind from shutting off whenever anyone starts talking Earthships because of the tire angle. There's just too much labour involved in packing tires with earth, to no purpose.

In my climate, for instance, I have heard that insulated concrete forms installed and used to contain rammed earth, mixed by truck or large mixer and tamped down by motorised tamper, would do the job better and more quickly than ramming tires full of earth with a sledgehammer. If the earth mix is amended to include 10 percent portland or quick lime, the structure takes on properties much closer to poured concrete.

I would design my structure to support the requisite weight, drop a moisture barrier, backfill around and atop the structure with largely mineral topsoil and cap with another water impermeable barrier for moisture control and for structural integrity of the earth pile, and drop a few tonnes of subsoil, topsoil, and perennial pasture and oak savannah analogue species.

An idea that I want to play with, but I could see easily backfiring, is using light wells through the earth topping, sealed from the top, and accessible through the bottom for cleaning and maintenance, and capping those light wells with forest pools. The pools themselves, in the lightly forested pasture savannah I am looking to create, would not only serve the typical purpose of ponds in forests, but would also, with a domed cap on the light tube at the bottom of each pond, stay clear of sediment and would bring light into the structure. I wouldn't expect to get enough light this way for indoor gardens, but that's what the southward-facing windows, or more than likely, four-season lean-to greenhouse entryway would be for.

The greenhouse would house tropicals and a permaculture-aligned aquaculture setup that would likely include an overwinter nursery for my outdoor pond culture systems. Greywater would run through the beds, and the resultant clean water would then go into the aquaculture, which would also filter through the greywater setup, further feeding the occupant plants.

So I have kept the earth part of the earthship, because I feel that utilising in-situ resources is a smart idea where possible.

I am keeping the structure ground-connected, as while the walls would be insulated, the floor wouldn't be, and that's where I would put my ground-sourced heat pump, which would pass hot air and hot waste water over heat exchangers using a high-capacity heat transfer fluid, which would deposit the heat energy in the soil column below, which would create its own heat island under the dirt umbrella outside the insulated concrete forms used to contain the rammed earth walls.

I was thinking that I could dig one "heat well," wherein a column of earth would be insulated, such that the heat would be trapped and stored for use in the winter, where the heat pump would move that excess into the living space at need. This could easily be augmented with black ducting in the direct winter sun path of the greenhouse, heating air in the black duct, which would heat the system. In the summer, the ductwork would simply move excess hot air to the same place, but would be shaded from the summer sun.

The greywater/food producing year-round indoor planter garden and integrated aquaculture have been retained.

And I have, with the dirt umbrella and on-grade construction with living roof, incorporated some of my favourite elements of wofati and hobbit holes.

Have I missed anything that any reasonable person would consider necessary in order to call it an earthship, or am I describing something so far removed from what was originally envisioned that we need a new name for it?

And to the original issue, how much can reasonably be altered for such a structure to still apply as an earthship, and are there any core ideas that must be retained, or the intent of the original idea be lost?

-CK

I like most of those ideas.  However, water on top of a structure seems difficult, based on its high density.  Also not sure if you would want an un-insulated floor in a colder climate.  

My understanding of the high thermal mass earthship concept is that it works great in areas with large temperature swings through the day (the U.S. SW).  In areas with extreme temps (the U.S./Canadian NE) you want higher insulation.  Of course, it is going to be warmer in the earth than on top of the earth in the winter, but you would still need a fair amount of supplemental heating in the NE, and a large amount of uninsulated thermal mass could quickly suck that heat away.

Anyway (and more to your original question), I think of earthships as anything earth-sheltered with a sun-facing lean-to greenhouse (so yours would count and Paul's wofatis would not IMO).