A 230 square foot classroom in Kent, UK, not only has a unique tree-house-like construction, but can also collect drinkable rainwater on its roof. The eco-friendly building’s roof collects rainwater and runs it through six reverse osmosis filters and a UV light filter to properly clean contaminants and kill bacteria. The entire building, including the filters, is powered by solar energy. For more details and pictures of this innovative classroom, click here:: Eco Classroom Gets Drinking Water From Green Roof