DLF, a real estate and construction company based in New Delhi, has developed cellular lightweight concrete, an eco-friendly product that offers a more cost-effective alternative to bricks. K P Singh, chairperson and managing director, DLF, said that the new product not only saves the topsoil, which gets eroded during the manufacture of bircks, but also combines environmentally hazardous flyash with cement, sand and water. The resultant product is lighter than brick and the buildings attain earthquake resistance even in quake-prone zones.