In Africa and Latin America, plastic bottles filled with sand are a cheap and effective building material. You just stack the sand-filled plastic bottles on their sides and bind them together with cement or even mud.
The result is a building material that is cheaper and stronger than brick, fire resistant and even bulletproof. The technique was developed by the German firm Ecotech Environmental Solutions working in Nigeria.
It goes to show that one person’s trash can be someone else’s natural resource.
Source: Plastic-Bottle Homes Are Popping Up Around the World by David McNair for TakePart.