What does an Earthship cost to build?

So someone found us the other day by googling this question:

 What does an Earthship cost to build versus a "traditional house"?

And the Answer is:

It Depends!

Always with the "It depends" thing... yes. I know. LOL!

But it does. It depends how much of an earthship you build, how much you build yourself, how many volunteers you have, how much your plans cost ($50k is not unusual for a custom home... including earthships... and that's not mortgageable!), etc.

The EASIEST answer is this: 

A normal Earthship, built in Taos by the powers that be... costs $225 per square foot.

A normal house, built nearly anywhere in the US, will cost you probably
$150 per square foot, if you do the "greener" version.

So you are paying $75 per square foot more... 

plus... in many cases, that doesn't cover the entire cost of the earthship. 

If you live somewhere like Alaska, where solar energy storage is challenging
because of low light levels for part of the year,
you can add another $75k to the cost for solar batteries.

But here's the kicker!

 A research study conducted by the website RealAssetsJunkie.com noted that the resale cost of an Earthship averages $191 per square foot (PSF). This means that a builder stands to lose up to $34 PSF if they choose to resell their home. An average Global Model Earthship is 1,700 square feet, which results in:

COST TO BUILD          1700 X $225 =         $382,500

(-)RESALE VALUE        1700 X $191 =          $324,700 

                                     NET LOSS =              $ 57,800

 

To help address these issues, a great floor plan, an inviting home, and thus, great detailing, is required. 

Start with our section Secrets of Great Curb Appeal for more information about how to build a home that people will pay more to buy.

♥

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Adapting your #home to changing circumstances: #UniversalDesign Tips and Tricks for #Accessibility

Most home designers these days fail their clients in regard to the long-term livability of their homes. We build homes that cannot easily be modified when someone becomes disabled or ill, or when our child is born with special needs.

Universal Design makes architecture that works for everybody, whether they be in a wheelchair permanently, on crutches for a couple of weeks, just having a little issue with “a hitch in their giddyup”, or even are just too little to manage bunches of steps and tight pathways. We find that our clients love the ease of getting around in spaces designed on Universal Design principles, and believe it or not, it also reduces the efforts required in mundane tasks like cleaning, which can be a bear when hoisting a vacuum and cleaning supplies up and around steps and landings. What is awesome about this, for us, is that many users of Universal Design in their home designs are finding that they are ready-made for the market for Baby Boomers who want something a little more manageable to buy for a home. So, they are selling their homes for a premium.

Here are the ways we can tweak the home’s design to make it work for everyone:

Floors and Landscape

• Use 1:12 slope ramps instead of single steps.
• Use a 3 foot door with a threshold less than ½” high.
• Make a lightly textured non-slip path 36 inches wide and without steps from the street curb and driveway to the home entrance. Use 1:12 slope ramps as needed and place 36” long landings at top and bottom of any ramps. Use handrails at locations where the path has a drop off of 12 inches or more at the side.
• Place trees so they do not drop berries or leaves onto the path. If trees already exist, make sure to maintain the path free of debris.
• Provide path lighting on the major access to the house.
• Provide a handrails and good lighting at steps.

Design

• Have a ground floor bedroom and complete bath.
• Place the washer and dryer on the main floor and use front-loading machines.
• Design halls and stair treads at least 36 inches wide.
• Use one landing for every 10 steps in a staircase.
• Provide a light switch at the top and bottom of stairways.

Entry

• Have a 5 foot square space available inside and outside at the front door.
• Cover the front entry so it is weather protected.
• Provide exterior lighting at the front door.
• Have a wipe off mat on both sides of the door to keep dirt and pollen minimized.

Kitchen and Bath

• Use sinks that can be “pulled in to”, without casework below, and install them 34” above the floor.
• Vary the height of countertops so little ones and big people can use them too. For instance, really tall people might want to use a kitchen cabinet in the bath. Those extra inches of height can keep a back from going out!
• Provide extra-long hoses for spray attachments.
• Use lever handles, not knobs, on sinks, baths, and tubs and use one handle to control both hot and cold water if at all possible. Locate the handles and faucet at the side of the sink instead of the back if possible.

Kitchen

• Locate the kitchen close to the entrance where you bring groceries in.
• Have a fire extinguisher located within easy reach between 27 and 48 inches above the floor.
• Use a sink 6 ½ inches deep.
• Use a dishwasher, and any other appliance, with button or push controls instead of knobs.
• Use heat resistant countertops.
• Use a side-by-side type refrigerator with sliding shelves and a water and ice dispenser in the door.
• Store heavy pots and pans in bottom shelves and drawers.
• Mount the oven with the top pull less than 48 inches above the floor.
• Use a range with push button controls at the front instead of sides.

Baths

• Provide a shower bench in a walk-in shower with a 36 wide opening at the entrance.
• Have a shelf for shampoo and soap in the shower at 48 inches above the floor or below.
• Provide a hand-held shower sprayer with extra-long hose (these are great for washing dogs and little ones too!).
• Add 1 ½” textured grip grab bars to the bath, toilet, and shower or install blocking for them, when framing the walls.
• Use a raised toilet seat.
• Use a door that opens out instead of in.
• Have a 5 foot wide circle open between all the fixtures and cabinets.
• Have a sitting bench on the edge of the tub.
• Have a non-slip bathtub and shower floor.
• Make the top shelf of the medicine cabinet less than 50 inches above the floor.
• Use a tilting mirror.
• For wheelchair users, leave 42 inches of open floor space on one side of the toilet.
• Locate the TP holder at 27 inches above the floor.

Cabinets, counters, and closets

• Use shelves less than 12 inches deep throughout.
• Use lazy-susan corner cabinets.
• Use rolling carts under counters.
• Use pull-out shelves.
• Use height-adjustable cabinets and closet shelves.
• Use loop or lever shaped drawer pulls and handles.
• Use easy-gliding hardware.
• Locate some wall cabinets at 48 inches above the floor or lower.
• Use cabinets on 6 or 8 inch tall toe kicks (spaces under the bottom shelf for toes to go underneath).
• Use clothing rods 22 inches to 44 inches above the floor.
• Use drawers 40 inches or less above the floor.
• Use 18 inch deep or less shelves in closets and pantries.
• Locate the light switch in pantries and closets close to the entrance.

Windows and doors

• Use 3 foot wide doors throughout, with 18 inches minimum of clear floor space on the handle side of the door.
• Use 5inch long lever type handles that curve towards the door and hinges with the tension reduced on them. Set them at no higher than 44 inches above the floor.
• Use swing-clear door hinges.

Electrical

• Locate switches and thermostats less than 48 inches above the floor.
• Locate outlets 27 inches or higher above the floor.
• Provide direct and indirect lighting in every room.
• Switch lamps at the door of the room they are in.
• Use nightlights in night-visited rooms like baths and kitchens, as well as the halls between them.

Finishes

• Use non-slip flooring.
• Use low pile carpets with a firm pad.
• Secure the corners and edges of rugs.

Of course, some of this costs more. We are offering all the suggestions we know of, because we have a wide range of clients to serve. Some people will want all of this and will be happy to pay for it. Others maybe not so much. Just know that you do have a choice!

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Why you should NOT retrofit your home to be more " like an #Earthship ”

Recently, I got an email asking me what could be done to an existing home to make it “earthship-like”. The text of the email I received was this: 

Hi, do you know of any resources available about converting an existing
traditional home structure into an "earthship" or more sustainable design?
It would seem to be an important niche, especially if a simple system could be
installed that easily bypasses traditional water/electric/waste systems.
Thank you.

I offered that you wouldn’t really want to do that with a bit of justification why, and we built on the conversation over a couple of days. During that time, the asker let me know that they had also asked the Earthship concept's main cheerleader/builder about what could be done to retrofit a traditional home to be more Earthship-like, and they were offered some ideas. 

The asker shared the response with me, and I am sharing the four ideas they were offered with you today… because the better part of what they were offered was TERRIBLE ADVICE. It was so bad that it took me a couple of days to begin to formulate a response. Even then, I was so distraught about how to actually help them that I called in backup... bringing in Marcus Lewitski, the founder of what was Earthship Europe (now Permahome), to help explain WHY these are bad ideas.

So. Let’s just start at the beginning - we don’t really know here what we are dealing with. Before ANY answer should be offered, we need to establish some baseline criteria by answering two important questions. 

1) WHERE IS THE BUILDING?

There is no way to know what type of design techniques will work without knowing where the building is. The orientation of the building on the site, its location, landscape, and climate are all critical factors in good design. 

 2) WHAT IS THE BUILDING MADE OF?

There is no way to know what you can potentially do to retrofit a building without knowing something about the existing construction of the home. Is it frame? CMU (concrete block)? Brick? Concrete? Is it in-ground, on-ground, or on piles? How many stories is it? When was it built? What are the insulating materials, what are the windows, and what is the roof construction? Is it designed for passive solar gain? 

These details are necessary to understand before we offer any ideas design-wise regarding retrofitting.

We will endeavor to explain what each of the Earthship firm's suggestions (in italics) mean to the potential re-builder in the Northern hemisphere.

EB Idea #1: “If your house has a South facing side with lots of windows or if you can add windows then maybe you can add a greenhouse.”

This answer seems to be predicated on the idea that the Earthship-style greenhouse with windows along the south side of the home is the only way to add a greenhouse. That’s just not true. AND the Earthship greenhouse is poorly designed, for a variety of reasons it took me two chapters of the book to explain. Let me do what I can to help illustrate how those issues apply to this particular question. 

So, let’s assume that you can build the earthship-style greenhouse on the south. Here’s how that can go wrong: 

A.      If your house has lots of windows on the south intended for passive solar gain and you add a greenhouse, then you will be diminishing the performance of the passive solar. And if you are in a cold, wet climate, and your home uses passive solar, you can increase your heating load significantly by adding a greenhouse.

B.      You will be adding high humidity to a building that is most likely not designed for it. Marcus reminds us that “in this scenario we are combining the moisture transpired by the plants with the moisture transpired by people, so in other words – a lot more moisture.” The reason the earthships work as well as they do is because the interior walls are made of concrete, which is forgiving, humidity-wise. A frame building will slowly start to rot from inside if the greenhouse is open to the home.

C.      The greenhouse may also cause the home to overheat, as it does in the traditional Earthships themselves for up to 9months a year.

D.      The greenhouse addition will change the way natural ventilation works.

E.       The typical Earthship greenhouse design adds thermal bridges that cause heat loss during winter and heat gain during the summer. So you have a much higher potential for uncomfortable hot and cold spots in the home.

To add to that, some locations don’t require greenhouses for growing food. In the American South, for instance, you can grow everything you need outside. So to add a greenhouse “just because” is an unnecessary expense that can actually cause more harm than good. And a greenhouse can easily cost $20,000 to build.

Here's how we recommend addressing these issues:

If you do want a greenhouse, you can put it quite literally anywhere except directly north of the home if it is attached. And, for that matter, it doesn’t need to be attached to the house at all. As Marcus points out so perfectly, “Attaching a greenhouse to a building shouldn't be a major problem. Ventilation will of course have to be taken into consideration and if the intention is to use the greenhouse all year round in a cold climate (i.e. a heated greenhouse) – one should implement a heat exchanger into the ventilation system to save on heating as much as possible. But then again – effective and energy saving ventilation shouldn't be exclusively utilized in the greenhouse.”

To resolve the issue of diminishing passive solar performance, a solution for locating a greenhouse without diminishing the performance of the passive solar heating is to simply locate the greenhouse on the west side of the house instead, like a wing facing south. In this way the sun's path to the thermal mass won't get obstructed by the greenhouse or the plants therein, and your plants will still be able to receive a lot of sun. The north wall of the greenhouse could then be constructed of a continuous wall of thermal mass (cob, adobe, bricks, stones etc.), insulated on its outside with straw or some other natural insulation material. There's really no point in having windows on the north side of a greenhouse.

Another factor that needs to be taken into consideration when trying to answer this question is what kind of passive solar we are talking about here. Passive solar in the sense that you want to store the Sun's heat from daytime to nighttime? Or a so called PAHS-system (Passive Annual Heat Storage) that stores heat from summer to winter? OR the kind of combined daily AND annual heat storage system that the Earthship concept aims at? This third kind of passive solar doesn’t really make any sense really, because the two first systems implement thermal mass in different ways. An annual system (PAHS) needs vast amounts of insulated thermal mass in order to store heat from summer to winter. You also need to consider the different alternatives of how to store and deliver the captured heat. But no matter what choices you make you will still need an appropriate location for this to work properly, and it needs to be a place with many sun hours even during winter. Especially in the great many areas that do not have adequate sunshine, this system doesn't make any sense, mainly due to the laws of thermodynamics. (The issues of which we describe in detail in the Passive Solar design chapter in the book.)

Marcus continues, “As I see it the daily system is a bit more universal in its application since it works quite well even with other heat sources than the Sun. It will even out the temperatures during the day by absorbing excess heat which it will later release during the night when the indoor air temperature falls. And since you have a substantially lower mass, it won't take as long to equalize the temperature of the thermal mass with the indoor air temperature and you don't have to burn extensive amounts of fuel in order for the house to stay warm during cloudy periods...

These are major issues and factors to consider whenever you build a house, no matter where you build it. Especially if you want to build sustainably. Good designers won't just blurt out advice like that just because it agrees with the product they are trying to sell. People are starting to become more interested in sustainability and it is in everyone's best interest that people get the best advice available... and that's simply not the case here, far from it.”

EB Idea #2: “The North side windows should be closed up. You can add insulation.”

We shouldn’t close up the North windows “just because.” The reason the earthships do this is because of the berm. If you do not have a berm, and do not live where there is ice or snow, there is NO reason to close up your north windows. In fact, there are many reasons not to. For one, earthships use operable skylights in those rooms in lieu of windows. Without natural light and ventilation, those rooms will be dark, moldy, and dank. This gets exacerbated when you introduce humidity into the home with a greenhouse. Also, artists and people with light sensitivity like the cool light that comes in from north windows. It’s more even and gentler on tired eyes.

Ventilation is critical, and to get that, we ideally want two windows on opposite sides of the room. That allows air in one side and out the other. If the south and north are no longer accessible for adequate air, then we can get sick.  That’s not okay. These two bad ideas (the greenhouse and closing North windows) put together can destroy what is already working with your home!

Adding insulation to the home is only a good idea if you live in an area that is either a) very cold, or b) hot and arid. The house should be ultra-light and raised above the ground in tropical or humid regions. So this advice is also not well considered for many potential remodelers. This is why we explain in detail in the book what the impacts of climate can be on the design of the home. 

EB Idea #3: “If you install a metal roof you can do water catchment.”

Absolutely true. The cost of a new metal roof these days, with an upgrade for most homes to the recommended energy-efficient insulation, can cost upwards of $35k. Adding cisterns can set you back another $7k. Excavating for them can be another $3k or so. Gutters and piping can be around $1k. So that upgrade will cost you $45k and allow you to catch water you can take a shower in but not drink. That’s an awfully expensive shower. Adding water filtration will tack on another $2k, at least, usually.

EB Idea #4 “And you could add solar power.”

Absolutely. You can. That’s a great idea and in many places, the solar power companies will get you into a system suitable for your area for around the same cost per month as your old utilities. Unless you live in far northern climates like Alaska, where the batteries required to make solar work can bring the system cost up to $100k or more. The good news is… while the battery technology is moving forward in terms of efficiency, durability and cost effectiveness, they are still very expensive. Hopefully that will change soon.

I hope this effort helps people to understand what could go wrong in their buildings if they blindly follow bad advice from people whose job it is to propagate the idea they are wanting to sell you. You deserve better information. That's what we are trying to get to you. That said, if you have been successful or unsuccessful at adding details from Earthships to YOUR traditional building, please let us know how it went, and we'll adjust this accordingly.

Blessings, everybody.

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Humidification Matters

Cool dry air is necessary for human comfort. Maintaining relative humidity below 50% prevents dust mite infestations, inhibits mold and mildew growth, and inhibits bacteria. Lower humidity also reduces the off-gassing of VOCs. In colder climates, wintertime humidity levels must be even lower - generally 30-40% - to prevent condensation on windows and other surfaces.

So part of what we have to plan for is dehumidifying wet air, and/or cooling down and humidifying hot/dry air. This process can be easily accomplished using a mechanical system, but when we do not use a system to manage it, we need to get creative. Some people warm up a crock of water on their wood stove to increase humidity. Others use misters in their greenhouse (though that can wreak havoc on your structural system if that system is wood-based). Some use fountains and waterfalls to serve the dual purpose of cycling the water in the cistern to keep it fresh while creating humidity within the livable areas. You might even use water walls with plants to increase humidification and oxygenation. Whatever you do, if you work with water, you need to make a plan for maintenance too… interior ponds and waterfalls require filtration and algae control to work correctly.

Alternately, people in humid climates may need to utilize salt de-humidifiers, using calcium chloride in most cases, which is readily available at your local agricultural store. This technique has been used by farmers for generations to keep hay from molding. You can also use air-based heating and cooling like stoves and forced-air systems to remove humidity from the air.

Note: interior ponds and waterfalls require filtration and algae control.

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Designing for Thermal Comfort

by Rachel Preston Prinz, Pratik Zaveri, and Asha Stout
Thermal comfort has been one of the most difficult aspects of designing buildings since we started building them. Our earliest civilizations were more concerned about portability in regard to their buildings so they could move from hunting spot to gathering spot depending on the seasons. Once we started planting crops, we needed to build more permanent structures to keep our stores of agricultural products safe, at a temperature they could safely be stored at, and moist or dry depending on the product.

Using natural materials in their unworked forms makes achieving thermal comfort in cold climates more difficult, because natural forms are almost never perfectly square, which means they do not fit together in a way that can prevent air and thus cold from moving through the walls.

The stone buildings of our earliest major civilizations in Egypt, Mesopotamia, and Greece had sophisticated tools which allowed them to work stone. They also had slaves and mason/architects who could tell the slaves how to work the stone. They used stone, not only for its monumental qualities which we still get to enjoy to this day, but moreover because a massive stone building is a great insulator from the heat. The cliff dwellings at Mesa Verde similarly use their overhanging cave shelter to provide shade for the hot summer months, while allowing the low-angled winter sun to come in and warm the spaces naturally. The stone buildings there were able to be tightly fitted with minimal working because of the type of sedimentary rock that was used. It flaked off in linear chunks that were relatively easy to stack tall without mortar.

But stone was not always available, nor were the slaves that many civilizations used to get these buildings built. Pretty much everyone else, everywhere else, had to make do with less formalized massive structures made of natural, easily worked, materials. They just came up with simple solutions for filling in the gaps. In log cabins, they would add a chinking of mud between the logs to stop the biggest leaks. They would add lime if they had access to it. Then they would put blankets and animal skins over the insides of the walls to keep the heat in and act like insulation. Even the teepees of the Plains Indian are lined with skins and blankets to keep the heat in. Igloo builders would often build their entrance on a sloped ramp that accessed the inside space below the living level so the heat inside the space would rise and stay in the building instead of escaping out the access hallway. Using this technique, they could heat up a space with just body heat and the heat from a lantern or small fire.

Early farmhouses in the Midwest and Eastern U.S. had a double entry vestibule, which acted as a buffer to present the direct loss of heat.

Tropical buildings, like the amazing bamboo Green School by Ibuku in Bali, Indonesia, are often built in the treetops. Tropical architects design their buildings like this to get up into the areas that are shaded and have access to cool breezes. They want to stay away from the earth because in humid locations, being near the earth also means being near water. These raised buildings stay drier longer during seasonal and storm flooding, and they stay cooler in the heat too.

These are just a few of the many ways in which humans around the world have found a ways of achieving thermal comfort.

Some building scientists will build their research around the idea that comfortable temperature limits are around a low of 65°F (19°C) in winter and a high of 80°F (27°C) in summer. However, when people are asked what their idea of comfortable really is, they will say that it is 70°F (21°C) in winter and 75°F (24°C) in summer. Knowing what your own comfort limits are will help you to plan your home for what you really need.

To achieve temperatures in these ranges, we really need to understand what makes those temperatures comfortable, and why they might be different in the summer versus the winter. To get to that, we need to understand that human comfort is dependent on heat retention and heat loss, which is affected by:

CONVECTION – the circulation caused by temperature difference; when air temperature is lower than body temperature, we get cold. This can be exacerbated by air motion.

RADIATION – when heat transfers are caused by electromagnetic waves; we radiate heat to cooler surroundings and absorb heat from warmer surroundings. Glass in winter can be 25 degrees cooler than the inside temperature at windows. That is a form of radiation. This causes “cold spots”.

EVAPORATION – changes liquid to vapor; this is another way we dissipate heat from our bodies: through the breath and perspiration. We can get hot or cold based on how much water we are evaporating from our systems.

We also need to understand a little bit about the physics of heat. Heat flows from the upper temperatures towards cooler temperatures. Like everything in nature, heat is trying to find balance or equilibrium. Because of this, the greater the temperature difference between two spaces, the more quickly heat will flow through them.

Building materials and insulation slow the movement of heat though them at a rate that depends on the properties of the material. No two materials work the same way exactly.

While it may be tempting to build as massive of a wall as possible, it is also important to note that resistance to heat flow (insulation) and heat storage (thermal) capacity are not the same. Concrete, brick, and stone are poor insulators, but work great as thermal collectors because they hold the heat for hours until the air outside them starts to cool down below the temperature of the warmth stored, and thus the heat starts radiating into the space.

One of the biggest ways we can improve thermal performance of the building is to minimize the air volume in the home. This allows us to use small systems to control airflow. Minimizing your footprint is the first step, and we will cover how to do that in later sections. The other important thing to consider is ceiling height, as this is what gives you your volume. The higher your ceilings, the more volume of air you need to heat, cool, humidify, or dehumidify. So soaring ceilings might not be the best idea throughout the house, unless you live in a hot/humid climate where getting that heat UP and out of the living space is a great idea for thermal comfort. When we have clients who want the beautiful effect of a large space but not the hassle of the larger systems, we suggest that they choose one room that is most important and make that space tall. Leaving the other spaces at normal heights will save you money.

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Using Windows for Ventilation

The first way we can invite natural ventilation in is one of the oldest methods of all - windows. We want to locate windows on opposite walls to facilitate natural cross-ventilation. We want to make sure that every room has a place for air to come in and a place across the room for air to move out. In climates with daytime breezes (and if you use the landscape techniques we offer here you will have those), open the bottom half of double-hung or awning windows on the side of the house that the breeze is coming from and then the high half of double hung or high awning windows on the opposite side of the home. This will encourage cross-ventilation.

If you have casement windows, which open vertically, you can use those to capture the wind in the evenings. Just open those that open toward the wind and also those that face in the direction the wind is traveling. If they do not open in the right directions, keep them closed, as they will invite warm air in and actually make it hotter inside!

One of the great things about living in a two-story or clerestory structure is that you can use the extra shade provided on the north side of your home and your basement and stairways to create a form of natural air movement called stack-effect, which can be effective for air circulation and cooling. This technique works by capturing the coolest, heaviest, air on the north side of the house and encouraging it to move through the house and take the overheated air with it. To use this technique, simply open the lowest floor’s north windows, and if you have double-hung windows, open the bottom sash. Then, open the doors and head upstairs to open the windows on the highest story on the south side of the home, or in the direction the wind is traveling to. If you have double hung windows, open the top sash on the upper floor. You can also open your fireplace damper for a similar effect.

In all cases, the windows the air will escape from (preferably a high window on the side the wind is GOING) should be open as wide, or wider, than the window air is coming INTO.

If a room is overheating, open the high part of the windows to let out the hot air!

Make this work for you! In hot and temperate climates, with cooler nights than days, close and lock your windows during the day to keep the cooler night air IN, and then open your windows in the evenings to allow the cooler evening air in to cool down the house again. Locking your windows is not just secure – it seals leaks!

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