One of the major expenses and hassles often associated with building a backyard granny flat is the sewerage connection, which can involve deep excavations and laying of large sewerage pipes (100mm-diameter) over distance (and hopefully, downhill) to the main sewer line. Saniflo solves this costly and disruptive problem by taking all granny flat waste-water into one single unit, and pumping pre-treated waste through a narrow pipe (eg: 40mm-diameter) which is easily laid above or below ground, uphill or downhill, to the nearest appropriate point of connection.