Estimating the unit costs for Home-Start support Michelle Sleed, Jennifer Beecham, Martin Knapp, Colette McAuley and Nyree McCurry Introduction Home-Start is a well-established national and international organisation which offers support to families with young children who are experiencing difficulties. Volunteers visit families in their own homes, usually once or twice a week, to provide both practical and emotional support. A three-year study supported by the Joseph Rowntree Foundation evaluated the costs and outcomes of Home-Start support to families in South-East England and Northern Ireland. The study was jointly conducted by researchers at Queen’s University, Belfast, and the Personal Social Services Research Unit (University of Kent and London School of Economics). For more information on the study see Box 1. Other outputs from the research are listed in Box 2. In this paper we describe how we estimated the costs for Home-Start services. Particular attention is paid to the costs of organising and supervising the unpaid volunteers who support families. This is an oft-forgotten element when costing volunteer inputs to health and social care. Methods The cost estimation exercise followed the same economic principles as described in the editorial (see pages 1–9). The cost estimates were based on information from several sources, the main one being a short questionnaire sent out to the organisers of each Home-Start scheme involved in the study. The questionnaire was built on our experience in PSSRU in the estimation of service- specific unit costs (see for example Beecham, 2000). It requested information about how the scheme operated, the services provided, the resources used and so on, while taking into account the type of data the services would have available. The questionnaire — labelled the Service Information Schedule — was piloted with two schemes in England before