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Photos: Hive Earth
Joelle Eyeson is a co-founder of Hive Earth, which is working to address the housing challenges in Ghana. The company supports using the traditional ‘rammed earth’ technique as much more eco-friendly than cement.

Lately, I’ve seen a number of articles about how cement is bad for the planet. (For example, this story on the mining of sand used in cement.) But what else can we use? We can’t cut down all our remaining trees.

In Ghana, a company interested in sustainable home-building practices is experimenting with modernizing some traditional materials. DW interviewed Joelle Eyeson, co-founder of Hive Earth. Here is the DW interview.

“What are the housing challenges in Ghana right now?
“Joelle Eyeson: There is need for around 2 million new houses in Ghana per year, but most of the building is concentrated in the capital Accra, where land is very expensive. The other issue is that when you build in more rural areas it then becomes expensive to travel to the cities for work. We knew that the majority of people in Ghana have a relatively low wage. We thought it is strange you have workers building these big houses that cost hundreds of thousands of dollars and they could never afford them.

“So our aim is to build houses that our workers and the majority of Ghanaians and West Africans can afford. The prototype that should be ready by the end of the year will cost roughly $5,000 for a one-room house.

“What exactly is the ‘rammed earth’ technique that you use?
The rammed earth technique is just a mixture of laterite, clay and then granite chippings. We use 5 percent cement to bind it but also do it using lime.

We wanted a way of building without using cement, because it is very toxic; especially in our climate it combines with the heat and humidity and creates a really bad indoor air quality.

“When we discovered the rammed earth technique, we thought it was great because it is basically like the traditional mud house, but updated. It’s a tried and tested technique that’s been around for centuries. Parts of the Great Wall of China were even built with rammed earth.

“In what other ways are the buildings eco-friendly?
“In Ghana it is so hot you usually need air conditioning systems in your home, but these are not always affordable, eco-friendly, or good for your health. We teamed up with some German engineers who gave us the idea of underground cooling systems. We dig around 8 feet or more until we get to the cool air underground. Then we use a solar pump which is constantly bringing the cool air into the home. Then it is only the cost of the solar pump (around $300) which people need to pay and there are no bills. …

“With our foundation we are also planning on doing more workshops with local communities, helping to teach them the skills of building with rammed earth. We are also planning on building eco toilets. … We want to enable people to come and learn about rammed earth, build something that is beautiful, eco-friendly and useful for their own communities.”

More at DW, here.

The rammed-earth building technique uses local materials in Ghana and almost no cement.

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When homes are destroyed in disaster zones, the Mobile Factory can turn the rubble into Lego-like building blocks to create new housing. They snap together without mortar.

Stella Dawson of the Thomson Reuters Foundation writes, “In Amsterdam a mobile factory, the size of two shipping containers, ingests rubble at one end, liquifies it into cement, and spurts out Lego-shaped building blocks.

“Call it rubble for the people, converting the deadly debris from disasters into homes and hospitals, cheaply and quickly.

“It’s the brainchild of Gerard Steijn, a 71-year-old sustainable development consultant turned social entrepreneur, who leads the Netherlands-based project to recycle the rubble from natural disasters and wars.

“He plans to create ecologically sound and safe housing by producing 750 building blocks a day from the debris, enough for one home at a cost of less than $20,000 each.

” ‘In disasters, you have piles and piles of rubble, and the rubble is waste. If you are rich, you buy more bricks and rebuild your home,’ Steijn said in a telephone interview.

‘But what happens if you are poor? In disasters it is the poorest people who live in the weakest houses and they loose their homes first. I thought, what if you recycled the rubble to build back better homes for poor people?’

“His rubble-busting Mobile Factory has fired the imagination of a landowner in Haiti and a civil engineer at the University of Delft. They have joined forces to test Steijn’s idea and build the first rubble community in Port au Prince next year. …

“Unskilled people can build the homes with the blocks, which meet demanding Dutch construction standards to ensure they will last for many years. [Hennes de Ridder, an engineering professor at the University of Delft,] expects further stress tests he planned for Peru in a few months will show the homes can withstand temblors of at least 6 on the Richter scale.” Read more here.

Photo: The Mobile Factory
Model homes built from cement rubble are on display at an industrial park in Amsterdam. The brightly painted homes are designed for disaster zones, using technology that creates Lego-style building blocks from cement rubble.

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