Background: Malawi is one of the countries with the highest urbanisation rates. With a population of about 662,000 (2008), the city of Blantyre is the largest in Malawi. Between 1998 and 2008 the city experienced a population increase of about 32%1. The continued influx of people combined with decades of inadequate urban planning, has led to rapid spread of informal settlements with deplorable living conditions. The major problems include overcrowding, inadequate housing and lack of basic services, in particular water supply and sanitation.