This reports evaluates the data from a home audit trial carried out for United Utilities in 2006-2007 to better understand the efficacy of water efficiency retrofitting. 4,642 domestic properties in Warrington were sent an invitation. 393 households took part in the audit and received a ‘water savers pack’, which included a basic shower timer and information on saving water. The data analysis showed that household dynamics, socio-demographic factors and the type of house account for 50% of overall household consumption and 41% on the per capita consumption. The installed devices reduced consumption, with low-flow showerheads being most impactful.