A Hyderabad based couple, Prashant Lingam and Aruna Kappagantula, have found an innovative way to reduce the landfill waste and to lower the cost of construction materials. They use PET bottles filled with mud as a substitute to bricks, and bamboo beams and columns are used instead of steel. Each mud filled bottle costs around one rupee, and the cow dung and cement used as plaster also cost less than conventional building materials. These eco-friendly materials not only bring down the total cost of construction, but being easily available, they can be used for low cost housing in rural areas. Using PET bottles also helps in clearing up non-biodegradable waste.