Based on the work of the WASHCost project run by the IRC International Water and Sanitation Centre (IRC), this book provides an evaluation of the water, sanitation and hygiene (WASH) sectors in the context of developing countries and is the first systematic study of applying the life-cycle cost approach to assessing allocations. It presents unit cost estimates of the WASH sector across geographic locations and technologies, including rural and peri-urban areas, and these are compared with service levels. It analyses detailed data from more than 5000 households across nine agro-climatic zones in Andhra Pradesh State in India. Key issues assessed include poverty analysis of service levels, cost drivers and factors at the village and household level, and governance aspects such as transparency, accountability and value for money in relation to unit costs and service levels. This is the most comprehensive study of the WASH sector in India and elsewhere that utilises the life-cycle cost approach, along with GIS, econometric modelling and qualitative research methods. Not only does it contribute to research and methodology in this area, but the analysis also provides valuable insights for planners, policy makers and bi-lateral donors. The authors show how the methodology can also be applied in other developing country contexts.