Earthbag domes are an inexpensive, sustainable and durable type of construction that can be used as residential or commercial buildings. This technique is also environmentally friendly, requiring no external inputs other than sand, water and labor. They were originally created in the 1970s by American architect Nader Khalili to provide low-cost housing for people who did not have access to conventional building materials such as cement or steel. His design has been refined over time and now earthbag domes can be found all over the world from India to America. There’s even one at NASA’s Kennedy Space Center! Earthbags come in a variety of shapes—round, square, rectangular—and sizes depending on what you plan to use them for: they range from small bags filled with soil, to large bags of up to 6m in diameter. The building technique consists of filling the earthbags—open-ended tubes made from woven polypropylene bags—with dirt or sand and then laying them out in a round or square shape on top of the ground, with barbed wire between each layer.
1. What is an earthbag dome and how does it work?
Earthbag domes are a type of building that’s made from sacks filled with dirt or sand, which form a strong but flexible shell that can be used as a home or even to build commercial buildings such as restaurants, shops and offices. The bags themselves look just like huge versions of the bags that you use to hold your clothes while travelling. Earthbag domes are especially popular in areas where people have few resources or access to conventional building materials, since they are extremely cheap and easy to make. They are also earthquake-resistant, energy efficient and environmentally friendly. The main benefits of earthbags are their low cost and durability, as well as the lack of any external inputs required to make them. The sacks easily break down into soil after around 40 years, meaning that you can use materials that would normally be thrown away for construction purposes.
2. Why Use Earthbags for Construction?
Building with earthbags is an eco-friendly option because they require no expensive materials, such as cement or steel. Cement is a leading cause of greenhouse gas emissions worldwide because producing it produces a lot of carbon dioxide and other greenhouse gases that contribute to global warming. Not only that, but cement structures are vulnerable to earthquakes, erosion and floods – unlike earthbag domes – because they’re made from non-renewable resources that aren’t as flexible as earthbags.
3. How to Build a Sandbag Dome?
Building an earthbag dome is a fairly quick and easy process, as shown in the video here:
The first thing you’ll need to do is calculate the amount of earthbags you’ll need – this will depend on the size and shape of your dome, as well as how many layers you want. Typically it takes around 4000 large (90cm x 190cm) sacks, filled with soil or sand, to create a dome that’s 3m high and 5m in diameter. The size of your dome will also depend on the height you want your walls to be – a higher dome will require more earthbags, as well as additional barbed wire and other materials for reinforcement.
The video above shows how easy it is to build a sandbag dome from scratch. You can use any tools that are available to you, provided that they’re sharp enough for cutting the bags. You can even use a simple flat-edged shovel instead of buying any fancy tools.
You’ll need to secure the earthbags by tying them together with barbed wire – tightly knot one end and then crisscross over the rest of the bag. This will keep it stable and prevent it from shifting under the pressure of the earth that you’ll be placing inside.
Step 2: Once your mound is finished, start to place your earthbags around the edge of the dome, at a 45-degree angle. Layer them in every direction until they’re all used up – this will provide your dome with extra strength and stability.
Step 3: Next, wet the earthbags with a hosepipe to make them slightly damp and help them stick together better. Once you’ve finished placing all of your soil-filled sacks, wet them again and cover them in a thin layer of mud or clay plaster, which will provide the dome’s surface with extra protection from water damage.
For added stability, you can also place a tamper around the middle of your dome. This will provide extra pressure to keep the earthbags in place. Some people choose to use old car tyres instead of placing tampers, as these are often easily accessible and free for anyone to use.
Step 4: Once your dome is finished, you can paint the surface with a mixture of lime and water if you want a white finish. Alternatively, you can leave it unpainted to amplify its natural earthen aesthetic. The video above also shows how you can add an extra layer of stonework around the dome’s rim for decorative purposes or to create niches where plants can grow.
You can create domes with any size and any shape, though they’re often circular because this is the strongest shape. You can also experiment with different materials for your earthbags, such as using hay bales instead if you want to make your dome more sustainable or eco-friendly.
There are many ways that you can use an earthbag dome, including as a home, greenhouse, school, shelter or retreat building. They’re simple to build with these step-by-step instructions and can be built by anyone who is willing to put in the time and effort required.
The sandbag dome is an environmentally friendly type of construction that is also strong enough to withstand earthquakes and floods. Most importantly, it’s a sustainable method of construction that requires only earth, water and human energy to build!
I hope you learned something from this post. If you’d like to read more about this topic or other topics related to permaculture and sustainability , then take a look at the links below: