Historically in Australia, mixed Construction and Demolition waste, and Commercial and Industrial waste has been traditionally landfilled. As environmental impacts of landfilling is becoming more evident New South Wales policy makers and innovators have begun exploring an incineration strategy to use such waste to generate electricity. The objective of this study is to utilise life cycle assessment to evaluate GHG emissions from this waste treatment strategy and the environmental impact of a case study facility, in Sydney Australia. The system boundary includes the thermal treatment of waste through incineration, the electricity generation from the steam turbine and air pollution control processes involved within. The functional unit is based on 1 tonne of input mixed Construction and Demolition waste and Commercial and Industrial waste. GHG emissions are calculated and the result shows that the facility generates 0.994 MWh/tonne waste and 1.16 tCO2e/MWh electricity. This emission is lower than a brown coal fired powerplant emission factor 1.31 tCO2e/MWh. The results from this study assists understanding and policy making for the future of Energy-from-Waste as part of the generation mix in New South Wales, Australia.