Archive for February, 2022
Creative, Affordable, Durable, Sustainable, & Adorable ADUs in California
Cal Earth inspirational workshops and hands-on classes offer a new way to build real estate
Today we took a field trip to the Cal Earth build & test site in Hesperia. This educational builder camp sits in Hesperia, CA because it has extreme heat, freezing cold temps, and is on a fault line. Additionally, Hesperia experiences flash flooding & washes, so it makes for a perfect test ground.
Superadobe buildings are Seismic & earthquake proof, fireproof, flood, & wind proof. They can handle snow loads and pressure. They don’t need rebar or concrete to build. They look super creative & flowy, but they are actually extremely structurally sound.
Many of the test structures at the Hesperia Cal Earth site are not maintained on purpose to see how they stand the test of time. This school has truly been built out by its students, and the first structure built in 1990’s is still standing today. It was such a fascinating experience!
Meet the Superadobe
If needed for refuge or quick builds, these structures can pop up camp in just a couple days. ‘Water village’, pictured here with Cal Earth volunteers Giovanni & Marco, is an on-site example of a cluster of single room homes, built to serve as a replica of what an actual refugee community might look like. Although designed to be temporary housing, this little village has been standing for the last 20 years.
Since superadobes are so durable, they can also stand the test of time for single family builds. Don’t feel like buying a ‘cookie cutter’ tract home? Cal Earth Institute offers preapproved plans – if you sign up for one of their workshops you’ll get a copy 😉 Of course, this is a part of the reason why we went. What’s a workshop without implementation?
We’d love to hear in the comments if you know anyone who has built a superadobe, or if you plan to build one yourself.
What Makes an Adobe Home a Superadobe?
Nader Khalili is the inventor & architect from Iran, who used to build skyscrapers for a living in Los Angeles, but he wasn’t fulfilled. He discovered Rumi, & changed his direction into sustainable building.
Not long after, Nader invented the ‘superabdobe’; which is a permanent Adobe structure. Rather than a traditional Adobe that cannot withstand a natural disaster, Superadobes are much more durable. Nader has since moved on from this realm, but his vision lives on through Cal Earth Institute.
Khalili loved biomimicry, mimicking designs and structures from nature. His designs include the ‘Seashell dome’; ‘Reptile walls’; and the ‘Koala pouch’. Not everything was biomimicry, however. The dome-obsessed architect also incorporated roofless domes for high heat; apses, and pottery domes.
Supply List to Build a Superadobe ADU
I loved how easy the supply list was. These were things that even I could carry, and didn’t need a huge truck to transport.
- 4 pt double pronged galvanized barbed wire; 12-14 gague thickness.
- 14 inch diameter bags to make 12 inch walls, just FYI you lose some width when you fill the bag with earth.
- Need coffee cans, or gallon buckets, depending on width of bags.
- Shovels,
- Tamper,
- Wheelbarrow,
- Scissors or knife
- A cement mixer or electric mixer makes things go way quicker.
- Level
- Wire cutters
- Water source
Want the FULL supply list? That’s still super short? Just TEXT “Cal Earth Supply List” to Angie at 949-338-7408.
Another thing that’s really neat is you don’t have to build a shelter at all with the earthbags from Cal Earth. You can build benches, stairs, planters, pools, fountains, fences…an Amphitheater for your Hipcamp…or whatever flowy and functional structure your mind conjures up 🙂
Pictured right is Daniel & our new Cal Earth workshop friends practicing with with the tamper. I can just see his wheels turning about what the next Flower Den Superadobe Retreat will look like – stay tuned, LOL!
Tips For Building a Superadobe Structure
A fun fact about superadobes is the heat transfer from outside is only at about one inch per hour. It won’t get too hot or too cold over the 12 hour daylight or nighttime hours. Not only do adobe’s prevent heat, they absorbs it, so that warmth slowly transfers inside to keep you comfortable at night.
Our first tips are about measuring and prepping properly for your fill:
- When laying barbed wire, measure from the center of your bag, and add 2 extra feet.
- When measuring for bag, walk the perimeter of the circle, and add 3 feet before cutting.
- Fold long bags in half & mark the middle. ‘Cuff’ the ends so plastic doesn’t fly all over.
- Partially flip bags inside out from each side, this makes them easier to fill. Be mindful to ONLY fill one side at a time.
More Pointers for a Proper Adobe Build
Since your main ingredient is earth from the land you’re standing on, you’ll want to ensure you’ve got the right mix. As you’ll be investing a lot of sweat equity, make sure to do a soil test before building to know how far you’ll need to go down in the earth to get past the living matter. It was stressed multiple times, make sure no living matter or roots are in your mix. Rocks bigger than your palm need to go too. If you can close your hand around it, then it’s fine, but larger than that should be tossed from the mix. Don’t worry though, it’s very forgiving to make the mix – there are adobe and superadobe structures across the world, & in all different types of terrain.
The tips kept flying fast at our one day workshop; I caught as many as possible. Figure they are best served here as bullet points:
- Keep everything dry & well ventilated if you are building in a wet area.
- Thickness of the wall depends on diameter of the build.
- Stabilize to resist erosion in flood zones, plan French drains & diversion. Your french drains can even be designed to water the landscape 😉
- Plan where the furniture will go before you start to build because a lot of it is built in; remember most furniture is square.. and there will be limited to zero squared angles in an adobe build.
- In case you’re only reading the bullets here, reminder to never use the top 1 ft of soil. Dig deeper to get to the inert materials like the sand, gravel, clay & silt.
- Orient windows south. Create & plan ‘Wind scoops’ facing the main direction of breeze in summer.
- PVC pipes, ceramic tubes, or even recycled bottles can be used for windows. Check out the custom ceramic windows pictured here.
- If doing radiant heat in floors, insulate under first!
- Utilize rocket stoves for simple heat sources.
- By the time you build up, its already compacted.
- Plaster right away, but don’t lay it in too thick, or else it may crack.
- Mesh or chicken wire is recommended to prevent cracking.
- Waterproof paint in wet areas.
- Note that limewash interior is anti fungal.
- If the bag needs to move, lift & pull. Don’t push.
Super Adobe Construction Made Simple
In essence, 4 main ingredients can build a pretty badass house. Sandbags, barbed wire, earth, & stabilizer. So easy. Sandbags can be made from polypropylene, hemp, or jute fiber. You can use long bags designed for adobes, or, just normal sandbags might work best if you’re doing the build with only a couple people. Stabilizer is added in the bag, like lime or plaster. From there, you’ll just cover the bags from UV rays and the elements while you build with a tarp, and you’ll be good. Note that jute might mold or rot, so it’s not recommended to build with it in winter. Supposedly jute is better for short term structures. The barbed wire acts as a velcro or glue between layers of bag and prevents the building from laterally sliding.
It seemed like the toughest part of the day was ‘completing the circle’ – which was the act of finishing each circular level on the stem wall. (That’s the straight vertical wall) It wasn’t difficult so to speak, just a process of folding both ends away from you, after propping the bag up with your feet (known laughingly as ‘bag wrangling’). Once the ends are properly sealed, you meet them up while keeping a tamp as a buttress at the seam. Then tamp the edge a bit so water goes out not in, with a slight angle to the outside. You can literally hear when the earthbags are tamped to correct compaction, the sound is louder and almost echos.
Additional important building techniques include a spring line for keeping the dome structure and trajectory of the dome even, and a compass to guide with proper perimeter and height. All these things were hand created with various tools and scraps we had on site!
Some Challenges Surrounding Superadobe Plans & Builds
No good thing comes without hurdles. In our current days of ‘buying a template ADU off Amazon’, the custom adobe build can face opposition.
Because the design elements with Superadobes are endless, it causes city officials to scratch their heads a bit. Designing these structures to easily follow the contour in the land and mold to the topography makes each one super cool, and super unique.
Let’s be honest….building officials are used to templates and squared angles. They don’t always understand domes, arches, and curves; and they aren’t extensively educated about them in the field. Confusion and inspectors don’t mix, so this means they can tend to deny the plans for your dream adobe without the proper education.
There was a point in time when Cal Earth had pre-permitted build plans, but alas, codes are everchanging… and they need to update permits. Feel free to donate time or funds to help Cal Earth get to the point of offering preapproved plans again.
Our Action Items to Support Superadobes
Locally here in CA, I’m going to see if we can get the City of Santa Ana to approve something. As Orange County’s epicenter, Santa Ana already has a ton of ADUs. Plus, many of the lots are flat with ample space for an additional small structure. And… my partner in life, Daniel, plans to talk to the building department in Sedona, AZ. We know Taos, NM is friendly to superadobes and green buildings; and would love it if you comment other adobe friendly build areas for the fellow nomads reading this blog 😉
In the meantime, one potential workaround with your city or HOA, depending on which one you’re in, is the umbrella of California’s statewide ADU law passed in 2020, SB 13.
How to Spread the Word about Superadobes and Get Involved
Of course, social media awareness always helps! You can follow & support Cal-Earth’s initiatives on Insta or Facebook. It also helps if you sign up for one of their affordable and educational hands on adobe building workshops.
If you’re inspired or thinking of building an ADU in Orange County, reach out, I’d love to come do a video tour whether you’re in progress, or have the finished adobe complete. Thought we could wrap this post up with one of Cal Earth’s favorite quotes from, you guessed, it, Rumi:
Orange County Real Estate Success 