We’ve been building lean and green since the start of the “great recession” and even in that relatively short time we’ve seen a lot of change come through the green building industry. It’s been getting bigger and better every year and it looks like that trend is only going to continue. With that being the case, we like to put in the time to see what others are doing to advance the field, no matter how strange their ideas may be.
In an effort to do just that, we megabussed off to New York to see Michael Reynolds speak about his Earthship concept. If you haven’t seen his documentary, he is the head of Earthship Biotecture, the organization behind these off the grid, super sustainable, hippy compound-esque homes.
As we’re both big proponents of sustainable design we couldn’t help but compare/contrast our homes to his. But since Earthship homes are typically built on large rural sites and we really enjoy the confinement of the urban lot it just didn’t seem like we could get an apples to apples comparison. So instead we thought it made more sense to take some earthship design principals and evaluate how they might perform on our urban sites; a comparison of rural sustainability vs. urban sustainability if you will.
Thermal Mass is the driving force behind the functionality of an earthship. During the day the earthship walls, made of compacted earth inside tires, store heat from the sun and releases it when the temperature dips. It’s like a natural heating system that senses the cold. All good stuff, but unfortunately it takes a lot earth and a lot of space to hold that earth. When land is expensive and space is limited it isn’t really cost effective to give that much square footage over to your HVAC system. Having the right solar orientation is also important, and something you don’t really get to choose in a city.
Perhaps a better solution for limited square footage is a thick thermal mass floor. Some concrete, about 4 inches thick or so would be good. You would still need to have the right solar orientation to get the best performance but detailed correctly you could probably knock those energy bills down a little more.
Energy production is another pillar of earthship design. We love this one. It’s hard to argue with producing your own energy and producing it where you’re using it. We have done this in a number of projects in the past like Skinny and will continue to in the future on Folsom Powerhouse. But what we prefer to do is leave the option open for people to add solar as an upgrade as it does drive up the cost of a home and can price out some otherwise very worthy homeowners. Shade from other buildings is still an issue here but in most cases it does work. Still, solar isn’t a ubiquitous solution in an urban setting.
Water Collection + Storage
Water collection and re-use is anther concept we love but unfortunately square footage lost to water storage would make rainwater collection for drinking, showering and flushing toilets a little ridiculous. The global model earthship uses two 5000 gallon tanks which would take up an area 16′x16′ and 8′ tall. That’s about half a row home basement full of water… something we generally try to avoid.
Gray water for flushing toilets is something that could be added. It makes a lot of sense, why not flush your toilet with less than pristine water? There might be a number of pluming code issues to work around, and inspectors scratching their heads at new connections but it could be worth it. What do you guys think, would you like to see a gray water system in your home?
Next up is Food Production. In these homes you can harvest vegetables grown from your shower water and go fishing in your tilapia pond (not filled with your shower water). This is a case where urban issues like limited square footage and the hard shadows created by other buildings make a good harvest unlikely. But if you’ve got the backyard for it we’ve got the landscape option for you! The foodie! Check it out on our customization page.
Food production is one of area of sustainable living where we like to say we give you the shell and then allow you to make your home as sustainable as you want. We’ll build it super tight, super energy efficient, with responsibly gathered materials whether you want that or not, the farming is up to you.
Earthsips also go full hog and treat their own sewage with the aid of their indoor plants and outdoor Botanical Cells. Without the indoor planted area and a small urban backyard we prefer to rely on sewage treatment plants for this one.
You may have noticed that many of the things earthships do that works so well on rural sites are really limited by the size and orientation of urban sites. These limitations boil down to one important condition: density.
Cities are really not cities without a density of people living and working together. Earthships, done the classic earthship way, require a larger lot, more open space, less verticality, and the ability to orient your house according to the south facing sun. The city doesn’t offer those opportunities, but it does offer less commute to your job, a variety of restaurants, bars, concerts and shops. Everything that makes putting up with all those people around you worth it.
Despite the fact that Earthsips require a few specific situations to function well, Earthship living is still pretty impressive. I mean these things provide their inhabitants with all the infrastructural systems they need to survive. I’d be willing to bet your home doesn’t do that, and that’s probably why they’re called earth-ships and not earth homes.Even more impressive is that all of this built in infrastructure functions as a closed loop system. They don’t take any energy in, except what they make and they don’t have any waste.
Ideally our cities infrastructural systems would function like an earthship for a million or so people. Homes, and buildings in general, have a role to play in that, but in an urban setting the variety of land uses free our homes from the requirement of fulfilling every need necessary for our survival. That opens things up for a wider range of amenities and more of that spice of life people are always talking about. In a lot of ways city living vs. earthship living is like living on the USS Enterprise vs. a type-6 shuttle craft. Sure with the type-6 you’ve got a 50 cochrane warp engine and four RCS thrusters with the freedom of open space, but there’s no holodeck. Why would you want to live without a holodeck?
But don’t think were overly critical of the Earthship. It’s a great look into sustainable living and the fundamental concepts of sustainable design. In fact we think it would be pretty cool to see these buildings take over a lot of energy grubbing suburbia. But until that time a lot of their overarching concepts can be applied at a larger scale to our own infrastructural systems. At the building scale we can look back at some of the material performances and design intent to inform our own designs and take the elements which work in a given setting. But only under the exact right conditions would the earthship, in its classic form, function as a good urban living ship. For sustainable urban living you’ll have to settle for modest living quarters amongst the majesty of the enterprise.