Kickstarter: The Art and Science of Natural Plaster

2012 was the year of Money & Life, 2013 was the year of Rocket Stoves (with followup review) and it seems that 2014 is going to be about natural finishes.

We’ve played around a bit with natural finishes and we expect to do so much more in the future. We do have a good book on the subject but when this kickstarter appeared I knew I wanted in on it. For me, without access to hands on workshops, something like this is the next best alternative:

It had a good burst of interest in its first days but has slowed down and I really want to see this, so please spread the word 🙂

From Earthship to Earthbags

This is a long overdue post and several external movement have prompted me to finally write it.

A while back I wrote how we moved from hemp construction to Earthships. Well the movement continues and we have moved away from Earthships too. This happened gradually and for numerous reasons:

  1. Expansive Clay Soils – we are proud owners of lots of clay-rich soil which expand when wet and contracts when dry. As I was doing research into Earthships specifically and underground houses generally this seemed to be a problem. Expanding clay soil can place tons of pressure on the walls of a house which can cause it to collapse. So for some time I lived with the question is it possible to build an Earthship in expansive clay soils? My conclusion was that the problems was not the clay soil but moisture.
  2. P.A.H.S – As I did more research I started to come across evidence hinting that Earthships do not work well in our climate (moist and cold). Just recently I came across clear evidence of this. I continued my research and was blown away by an old book called Passive Annual Heat Storage. The book introduced a method by which an underground house is insulated with the soil around it, transforming the surrounding soil into a huge heat battery that charges itself during the warm months of the year and discharges during the cold months. The book confirmed my suspicion that the problem with clay soils is indeed moisture and not clay. The “insulation umbrella” concept described in the book (together with other moisture related strategies) provides a solution to keep the clay soils surrounding the house dry – providing a resounding (even if for now theoretical) answer: yes, underground houses can be built in expansive clay soils by keeping moisture away and in doing so neutralizing the “expansive” quality.
  3. Tires in Romania – we could not find a feasible way to get used tires in Romania.

Empowered by the P.A.H.S knowledge I continued my exploration and started looking into earthbags (it’s a terribly designed and uninviting website but has valuable information). I loved the simplicity and ease-of-construction when compared to ramming tires with earth. I would not have considered it a feasible method of underground construction had it not been for the P.A.H.S. method. I do now.

… and so this is the house that we plan to build.

Of Earth Inside the Earth

The house will be completely buried in the ground except for the south-facing aspect. It’s intended location is on gentle south-facing slope. We will excavate for it into the slope.

Most of its walls will be load-bearing earthbag walls. Hopefully our clay-rich soil (that will be excavated to make space for the house) will provide most of the material needed for the earth-mix that will go into the bags. There is no material more local than earth.

The floor will be an earthen floor and the walls will be covered with earthen finishes.

The roof is an as yet unresolved challenge. It too will be covered with earth and will therefore need to carry a very heavy load (current estimation 1.2 tons per square meter). This weight will probably be supported by round timbers though this is not yet final.

Spacious

We are planning a house that will be ~200sqm. It is designed to spaciously accommodate a small family. It will have a main part and a smaller, attached living space for additional privacy.

P.A.H.S. – 21 Degrees Celsius All Year Long

Thanks to the P.A.H.S. insulation umbrella the house will (after 2 or 3 years of acclimatization) eventually settle on a steady all year-long temperature of 21c. During the warm/hot months excess heat will be stored in the huge earthen thermal battery. During the cold months heat will be drawn from the thermal batter.

This means that we will not need any additional energy input to keep the house warm. Even the water supply that runs under the insulation umbrella arrives at the house at 21c which means that less energy is needed to heat water.

The temperature of the house is a function of how much heat gets into the house (which depends on how much windows it has) and how much it can store (depends on numerous design factors). It is nearly impossible to change the temperature of the house after has been established. Any attempt to heat it will be futile because the energy will be drawn into the thermal battery surrounding it and you would need to invest a huge amount of energy to change that.

Imagine not having to cut down a single tree for heating!?

Rocket Stoves

We do expect to have at least one rocket stove for comfort … to boost the temperature to 23 -24 degrees when we want to … and to heat water during the months when solar-heated hot water is not available.

 Ventillation

ventilation is, we’ve come to believe, an important and often missed aspect. The air in the house should be regularly exchanged. Fortunately the P.A.H.S. strategy includes a passive ventilation system (no fans and no electricity to run it) that brings fresh air into the house all year-long at, you guessed it, 21c. The ventilation system also plays a key role in storing excess heat when it is generated (summer) and retrieving it when it is needed (winter).

The trick (and the one challenge that still worries me) is to build the house air-tight. You should not need to open/close windows in this house ever. During the summer months the passive ventilation system will draw hot air out and store the heat in the thermal battery (instead of letting it escape out windows). During the winter months the passive ventilation system will draw air in from the outside, running it through the thermal battery and bring it up to room temperature.

Imagine fresh air during winter at room temperature (and stale air removed) without losing heat to the cold outside!?

Passive Refrigeration

Michael Reynolds in his classic Earthship books points how ridiculous refrigeration can be: we build boxes to keep the cold out, spend energy to get those boxes warm then build smaller boxes inside and spend more energy to keep those boxes cool.

With a slight change in configuration, the same passive ventilation method that is used to regulate the temperature of the house can be used to create a cool space (let cold air in and warm air out). In the Romanian winter that cool is cold enough not just to refrigerate but also to freeze.

Our intention is to build an insulated (from the warmth of the house) space within the house that will harvest winter coolth. That coolth will be stored in water bottles that will freeze. The space will be divided in two. One part will hold a freezer that will be exposed to the natural freezing temperatures. A second part will hold a refrigerator. Both will be unplugged during the winter months. When spring sets on and the ice melts and there isn’t enough coolth they will be plugged back in and run on electricity (which is once again available as the days get longer and the sun shines through).

Photovoltaic Electricity

We would like to be able to live off-the-electric-grid. The first step towards doing that is by drastically reducing consumption:

  1. The house is naturally heated so that no electricity is needed for heating.
  2. Hot water is pre-heated due to the thermal battery, then heated with an efficient rocket stove during winter and with a solar-hot-water panel in spring/summer. Very little electricity needed for pre-heating small quantities of water.
  3. Refrigeration is designed to work on the naturally available coolth of winter when there is very little sunshine to produce electricity.
  4. Large south-facing windows and a one-room-depth house design provides plenty of natural light all year-long.

This leaves us with some lighting and other smaller electronic devices (computers and such). This should enable a photo-voltaic system that will provide all our needs in summer months and most of our needs in winter months.

Attached Greenhouse

The front of the house will be a large greenhouse that will serve multiple functions:

  1. Harvesting heat during winter months.
  2. Extend the growing season.
  3. Growing plants that can not tolerate the harsh winter (lemons? avocados? even bananas?)
  4. Having a pleasant green space to spend time in during the cold winter months.
  5. Consuming grey-water created in the house (this is much easier for us since we use composting toilets and do not have to deal with black-water).
  6. A transition space between the outside and inside (keeping the inside cleaner).

Rainwater Harvesting

For a long time we were faced with a dilemma:

  1. A standard roof that will harvest rainwater for the house but somewhat compromise insulation (all heat inside the house rises) and durability (all mechanical roofs are prone to deterioration and require maintenance).
  2. A living roof that will provide superior insulation and durability but is practically useless for harvesting rainwater (10-15% of a similarly sized regular roof).

After long deliberation we came up with a solution that will provide us the best of both worlds. The house will be built with a living roof (a relatively massive one) that will complete the insulation umbrella.

We will be building a “mirror” structure of the house slightly uphill. This will be a simpler and cheaper structure. It will include a workshop, storage spaces and an open yet sheltered work space for a summer kitchen and other outdoor activities (some of these functions are now unmet or just temporarily resolved). This second structure will have a metal roof for harvesting rainwater that will be stored in an underground cistern that will supply the main house.

Summary

None of these technologies are new. All have been implemented in one way or another. We do not yet know of a house that has been built using all these technologies combined in a climate like ours. It has taken almost 3 years of research by trial and error to reach this formula which has the potential to be an affordable, ecological, sustainable and scalable method of construction.

Scalable is an important quality worth explaining. From what we’ve seen most eco-houses fall into one of two groups. One are small hobbit-hole-like homes which are often the result of do-it-yourself builds with natural materials (these do not scale up very well). The other are large and expensive homes that rely on expensive and complicated technologies to achieve an illusion of sustainability (that often ignores their embodied energy and their technological dependence). We are trying to create something that is in between these two worlds. The P.A.H.S. method can be applied to any size home and it is a core component in the overall efficiency of such a house.

This will hopefully be a very-long-term house.

Evidence That EarthShips Do Not Work in Europe

That title isn’t quite fair because it isn’t exactly true. But given the hype around Earthships I felt it is a deserved.

This short post was prompted by a longer article where the author inquires into the performance of Earthships in Europe. He raises exactly the same questions I encountered in my research. He made an effort to reach out to known Earthship projects in Europe to inquire about their performance and this is what I read between the lines:

  • There are very few Earthships in Europe.
  • Most European Earthships do not have permanent residents (if at all, cats do not count).
  • There is very little information on performance.
  • From what little information there is, it seems there are severe performance issues.
  • There is very little sense of joy from all this.

The author is less blunt then me. I’ve written before that I think the Earthship “formula” is wrong for a cold and moist European climate. I also feel that the knowledge around Earthships is incomplete because I did not come across any information on why they are designed they way they are,why they work where they do and why they do not work in the European climate.

I did however find the Passive Annual Heat Storage book where (1) I finally found explanations on how underground houses behave and (b) answers to all the questions presented in the linked article and then some.

Australian Earthship Build Video

Dan contacted me and sent me this video of an Earthship built in Australia. The video includes image sequences that are packed with information. If I find any more information on this build with still pictures and words I will update this post with it.

Big Water Ouch

The day before yesterday I was watering our raised beds. We shouldn’t need to water the raised beds but we do because (a) we built them late in spring (its best to build them in the fall) so they did not have an opportunity to fully absorb water; (b) because they are still not properly mulched. As I was moving through the beds the water pressure in the hose began to drop and quickly diminished. With some trepidation I went to check the problem.

First I checked that we still had electricity. Check. Then I went to make sure that the pump was not idling (struggling to pressurize) and it was. I unplugged it and plugged it back in and after some struggling it managed to pressurize. Check. Then I looked into the well and it was empty. Not check. Ouch. Big Ouch.

We thought that maybe the springs in the well had gotten clogged and needed to be cleaned. First thing, I took a bunch of empty plastic bottles and went to bring drinking water. Then Andreea called Sammy – the guy who cleaned our well last year – and asked him to come again. He came yesterday evening. We most of the remaining water on the raised beds and Sammy went down to check things out. He did a bit of cleaning up … there wasn’t much.

We overused our well. It is our only water source. It is summer. It was fine last year but last year we weren’t watering raised beds and we weren’t showering much. The showering isn’t nearly as demanding as the watering … so my assumption is that the watering drained our well.

Most people here do not water their fields. They simply can’t. Those that do dig small lakes … deep enough to penetrate the aquifer and draw water from it  … they don’t do it from their house wells. Though our raised beds are a relatively small garden … watering them is simply not possible with the supply of water that we currently have. This is where the rubber meets the road … how resilient will mulched raised beds turn out to be? Time will tell.

The well is filling up again … but it isn’t reaching the level we know it to be. Painful lesson learned.

Tires Together

One of our core projects here at Bhudeva is building our future house. We have been doing a lot of research on sustainable and ecological construction and we have been facing many challenges in bringing existing knowledge into context for our life here in Romania. Our latest design envisions a mostly underground house that will provide us with a year-long steady temperature of 21c without any energy inputs (neither for cooling in the summer nor for heating in winter). The core of our design is based on the concept of Earthships. At the heart of Earthship construction are massive walls built of tires that are packed full of earth.

So for many months we’ve been looking and asking around about tires here in Romania and this is what we found out:

  • Most tire dealers and repair shops sell some used tires that barely have treads but can still just barely be driven for 15-20 ron a tire (just to be clear – they are sold to people with old cars who can’t afford new tires).
  • Tire dealers are required to “recycly” through the state (represented by licensed operators) a certain amount of tires to offset new tires that they import.
  • The dealers are paid a symbolic 50 ban per tire collected from them.
  • Most of the collected tires are then sold off to different uses . Some are recycled (yey!!) into products such as car mats … however …
  • Many (we suspect most) are sold at a premium of 10-20 ron per tire (purchased in quantities of tens of thousands) to cement manufacturing companies (and their likes) who use them as fuel (boo!!) – it seems that a single tire contains a equivalent of 7.5 liters of oil!
  • We know of at least one giant pile of tires in Cluj-Napoca that is just sitting there slowly decomposing in the sun. We assume that other such piles can be found all over Romania.

Used tires is a waste product we (especially those of us who drive cars) are all responsible for creating. The concept of Earthships (built with earth-packed tires) was born out of recognition that this huge source of waste (available all over the planet) can be put to good use in creating houses (which it would seem are also needed all over the planet). Any recycling of tires requires high energy inputs (often starting with shredding). The thought of all the toxicity released when tires are burned as fuel (a single tire contains a equivalent of 7.5 liters of oil!) is mind-boggling. When used to build Earthships the tires are used as is and because they are completely buried they do not decompose or release any toxic gases (which they do when exposed to the sun).

Whenever we speak to someone in Romania about needing tires we quickly encounter an opportunistic greed. Regardless of the “asking-price-per-tire” we would also need to find a solution to sort through tires and have them brought over to our place which incur additional expenses. All this caused us to rethink about construction with tires – suddenly it seemed that concrete blocks that easily snap together would be much cheaper (and way faster to build with) then working with tires. However we really don’t want to resort to massive construction with concrete … so we scratched our heads and though of you … yes you 🙂

Inspired by the awesome waves of goodness we encountered with the introduction of Cutia Taranului we decided to once again try collaborating with you – our fellow Romanians. Also in the spirit of Cutia Taranului we realized that the best way to get tires would be to go around the existing system rather than through it. It boils down to this … the next time you buy tires we would like to ask that you keep your old tires, don’t leave them to be used opportunistically as fuel.

Now look at your old tires … what do you see? Look closely … you are holding a personal invitation to visit with us at Bhudeva including at least a pleasant conversation, a tour and a tasty cup of herbal tea … and best of all you have become a contributer to a unique experiment in sustainable construction taking place here in Romania.

For our house we are going to need about 2000 tires (though we have other structures planned … so we will try to collect much more). Tires come in different sizes which are indicated with a combination of numbers printed on them. All you need to look at is the first number – the one that has the letter “R” in front of it. We need tires that are labeled as either “R15” or “R16′”. The larger “R16” tires will be used for the base of our walls and the “R15” tires will be used on top of them for most of the wall.

Lastly … since we are talking about garbage 🙂  We are also going to need empty cans, empty wine bottles and used cardboard boxes. So if you are already holding on to tires an invitation to visit Bhudeva then please  hang on to these things you may be tempted to throw out 🙂

Since tires are not often changed this initiative may move a bit slow so … please do spread the word to your family and friends 🙂