Author Archives: sam

I got to know Cynthia when requested to participate in a development of a sustainable tourist resort in the Otomí reserve close to Mexico City. Cynthia has a lot of experience in construction with many different natural materials and has been recently awarded by the mexican government as inspiring young professional with the Injuve Price. When talking to her about the Hack-Shack, she was so kind and willing to help me out with some architectural drawings and advising about different natural materials. To respect the spirit of the Hack-Shack She proposed to use Tadelakt as a finishing for the Bathroom.

Tadelakt  is a waterproof plaster surface used in Moroccan architecture to make baths, sinks, water vessels, interior and exterior walls, ceilings, roofs, and even floors. It is made from lime plaster, of course mixed with sand from the holy Hack-Shack land, which then is rammed, polished, and treated with soap water to seal the cavities in the plaster to make it waterproof and water repellent.

On the featured Image, Baltazar, our Hack-Shack Grand Master Mason and Cruz Azul Master Fan, is rubbing the Soap Water onto the lime plaster with a quartz like stone. Baltazar did an outstanding job throughout the whole construction. Learning and applying the Tadelakt technique, demonstrated by Cinthia, wasn’t any different.


The first bathroom wall out of Tadelakt. Imperfections are part of our learnings … and provide a certain “caché”

The fact of using the sand of the very place in different shapes and applications as the outside plaster, the inside wall lime plaster, the Tadelakt bathroom plaster and the lime floor generates a very cosy feeling. When walking around the house, you realize that the grain and texture of the finishing are similar and just vary slightly in colors. This provides the feeling as if the house is shaped by human hand and fits completely into the surrounding.


It feels right to create your housing with local material, finally they are made by their very environment and will therefor blend into the site for eternity.


View outside the bathroom. You can observe the fine Tadelakt finish on the right side.


(from left to rigth) Josue, Cinthia and Octavio discussing the lime floor test we did on the water cistern


Mixing natural pigmentation as coal and earth into the lime finishes.

Palapa – Beautiful Hatched Roof


So after the passing of Tropical Storm Bud. And the house withstanding the extreme weather back to where we left of… the roof. The roof is actually the easiest part to make with natural material. Hatched roofs have been around for centuries or millennials.

So for the hack-shack we used palm tree leaves as commonly used in Baja California. There are different methods of how to place and hatch the leaves. Each one looks different and is not or less laboursome.

I decided for the “hoja-doblada” (in English: folded leave), simply because I liked the pattern look.


The load of Palm leaves for the Hack-Shack roof..

This technique requires quite some water to wet the leaves so they fold without breaking. Additionally a second layer of leaves go on top.

There is broad knowledge that goes with the palapa construction. The leaves should be dry when cutting them from the palm tree. Also it should be done at full-moon. Supposedly for the roof not to rotten…

The wood pieces are held together with dried cow skin that have been treated with lime. Local cow, of course 🙂

Here a picture sequence of the the making…


The first timber to build the roofstructure


Roofstructure almost completed…


To receive the leaves…


On the inside you see how layer by layer is folded.


Working from the lower end upwards to the roof top


A lot of scaffolds to work in heights and bring the loads of palm leaves from the floor onto the woodstructure…


Almost closing the top…


A beautiful completed roof providing a lot of shade.


So again we used only natural material for the roof. Palm tree, timber and cow skin…

I have to say, the whole process of the roofing was extremely fast. In less than 3 weeks the roof was finished.

Chepo, the palapero, did an outstanding job, creating a beautiful finish of the roof. Really nice handcrafted details that we will appreciate for many years, looking at the ceiling…

And I have to say that the palapa roof is one of the parts I like most. It made the house feel like a house and embeds a lot of warmth, protection and love to the building. Now I really look forward to live in the hack-shack…

First Real Test – Hurricane Bud

So actually I wanted to share how we built the hatched palm leave roof. Nevertheless today I have a bigger concern. Bud.

Hurricane Bud is heading straight ahead to the HackShack!

So this will  be the first test for the house and roof to see whether the construction is really solid and withholds tropical storms and hurricanes.


Bud, downgraded to tropical Storm, has reached Baja California Sur and will swoosh over the Hack-Shack tonight… 

Since the beginning of the project and all along its making, many people questioned if a house built with natural materials will withstand natural disasters and I could never answer the question with certainty. I always had to answer: “We will see…”.

Tonight we will see… and I will let you know! 🙂

Inside Plaster

Yesterday I wrote about the arrival of the Biodigestor, but I haven’t shared any update on how the house has been coming together. So here we go back to October 2017 to share with you how we did the inside plaster.

As you know the goal of the hack-shack is to build with natural and locally available material. So for the inside plaster we choose mud and clay that we found a few miles away in the same valley. According to Ricardo’s mixture we added straw and horse manure.

The advantage of clay is that it has an isolating effect and can absorb and release humidity and therefore has a balancing effect on the climate within the house.

We placed a wire mesh on top of the sandbags to hold the electrical piping in place. But basically you can apply the clay mixture directly on the sandbags.


Ricardo applying his clay mixture on the inside.

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The inside of the house starts to change with the first clay applied.

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Naturaly the clay forms cracks when drying on the sun. Looks like an arid desert.

To cover the clay we used another widely common natural material, lime mixed with sand. Of course sand from the holy hack-shack land! 🙂

Lime has been used for millenials in construction and has many properties. It is water repellent, it has a very high PH and makes a natural barrier for bugs and is breathable for moisture to evacuate from the walls.

So we apply the lime and sand mix on top of the clay plaster, so it fills the cracks and gives a nice white painting. We just covered with one layer. Some people say you should apply several layers.


As a proof we left visible a little square of sandbags and clay plaster

The nice thing about the walls of the hack-shack is that it is almost completely natural and built out of very local material. The walls out of sand, clay and lime plaster. The walls look and feel really solid. I feel really excited about how the hack-shack is coming together.  It starts to turn out even better than I had imagined 🙂


Applying the different plasters, sand, clay and lime


The white lime plaster gives the house a greek mediteranean look


The Hack-Shack ready to receive the roof… coming up next:)


Homebiogas – The solution for cooking

I participated in last year’s Homebiogas Kickstarter Campaign and today I got all excited at work when receiving a parcel from the amazing Start-Up called Homebiogas, which I could visit in Israel this spring.

As you all know the Hack-Shack is supposed to be all-off-grid and affordable. An electric stove was not an option, since it consumes a lot of electricity and this would increase the expensive battery and solar panel requirements and make the project expensive.

As we do in Kessel, I try to use available resources for the Hack-Shack. Homebiogas is a domestic biodigestor that turns your food (and other organic) waste into energy.

So basically I will through my organic kitchen waste through the kitchen window into my Homebogas unit, where it will be turned into gas that I will use for the stove and cooking. The biodigestor also produces liquid fertilizer as a sideproduct, that I will use to grow my vineyard! 🙂 Of course the homegrown wine has to be tasted with a fresh catch from the sea of Cortes 🙂

I am really looking forward to try out Homebiogas to see how functional it is on a day to day basis. I will of course let you know if I get sufficient gas to cook my breakfest and coffee 🙂

So the message here is: The solution to sustainable housing and energy supply is not always solar panels and electricity. Not even in such a sunny place as Baja California. When determining your energy supply, consider in what form you use the energy (in this case it is heat for cookint). Then consider all available options that are available in your context to source the energy as local as possible, with the fewest transformations possible and that the energy supply is available at the moment you require it. Remember, electricity is noble and easy to transport, but dificult to store unlike gas or heat.




Outside plaster: and the house looks more like a house!

Now that the walls are pilled up we had to decide on the plastering. Last year we made two trials and both had its advantages and disadvantages.
We tried to make a plaster with the sand from the construction site and mix little mortar to it. The idea is to use the most possible local material to avoid transport and material cost. The other advantage is that mortar based plasters are water proof.
In Baja California there is little rain, but in hurricane season rain can be so heavy that earth walls can literally be washed off.
On the other hand the disadvantage of mortar or cement based plasters is that they don’t let any vapour pass the wall; the wall can’t breathe and humidity can accumulate.
The other plaster we tested was earth plaster. Earth plaster has the advantage that it absorbs well humidity and has advantageous thermic properties. Earth plaster breath.
In view of our experimental hack-shack we decided to apply both plaster techniques. On the outside we applied the sand and mortar solution to have a waterproof shell for hurricane season and on the inside we will use earth plaster to improve the housing climate and feeling.
The south wall being plastered…
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first layer of of sand and mortar plaster being applied on the sandbags

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Several layers of plaster are required to fill the volume between the gaps of the sandbags

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giving a second layer

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starting to look good. on the upper edge the iron bars for the wooden hatched roof are visible.

Now that we have the electrical conduits and hydraulic wall passing with the wire mesh put in place we were able to apply all the plaster. Since the sandbags are uneven there is a larger material requirement of plaster. This is a disadvantage of the sandbag construction to be considere.
North wall is the most complete wall, protecting from the winter winds.
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north wall with the three windows is almost ready

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window finishing – the inside of the window frames are also filled with plaster

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scaffolds are needed to reach all the parts of the walls

West wall being plastered. All the utilities as, water storage, dry toilet, biodigestor, solar water heater as well as battery storage will be placed on the west side of the house.
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Piping and conduits in the walls

Whilst piling the sandbags and during the last months we had to review several times all the pipings for water connection, the gray water drains and all the electricity installation to define where to set the electric sockets, switches and lights. All these details are important to prepare the walls for an easy set up of the electric and hydraulic system.
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Passage for urine drainage pipe. A PVC pipe inserted between the sandbags. 

I designed the house to only have water on the ground level and on the west side of the the house. This simplifies tremendously the piping and reduces material cost as well as improves the pressure in the hydraulic system. We identified the places where the pipes have to run through the wall and there we inserted a schedule 40 PVC pipe to provide a spare opening and simply pass through the regular piping lateran.
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The electrical cases can simply be screwed on the wooden part of the Ecobeams

For the electrical installation the wood pieces of the eco beams provided perfect support to screw the electrical cases for sockets and switches. The flex tube for the electrical wire can be accommodated in gentle turns along the sandbags. The plaster then will cover the complete wire, tube and cases.
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running the electrical conduits under the wire mesh

Regarding the electrical installation i still feel completely insecure about the outcome. I purchased the solar panels and the batteries to supply the off-grid hack-shack.
To save energy we will use LED lights. LED lights run on a low voltage DC. So I designed two electrical circuits. The first being 120 VAC to provide “regular” domestic electricity through common sockets powering all appliances. The second circuit will run 24VDC and will power the illumination circuit.
With this design we can separate the illumination circuit and supply the lights directly from the batteries and only the appliances will use converted electricity provided by the power inverter.
Nevertheless there are almost no lamps, switches and proximity sensors for 24V out there in the market and I have the feeling that I will end up producing the lamps by myself. I sneaky feeling is overcoming me that I will require help in this aspect to not produce another fuck-up… Let’s trust that the universe has the solution ready for me and I just haven’t seen it yet!