United Utilities Home Audit Project (2008)

This report brings together findings from a trial carried out by United Utilities in 2006-2007 that investigated the effectiveness of water-efficient devices. 4,642 domestic properties in Warrington were sent an invitation. 393 took part in the audit and received a ‘water savers pack’, which included a basic shower timer and information on saving water. Further devices were installed where appropriate including water efficient showerheads, dual flush retrofit and save-a-flush cistern displacement devices. 67 % of 211 measured households were able to save water, on average 20.6 litres per property per day, which represents a reduction in water use of 6.8%.

SUMMARY

OBJECTIVES

Determine the practicality of fitting and promoting a range of water saving devices; Gain a better understanding of the likely costs of fitting these devices;
Determine associated savings of these devices through property and DMA metering.

REASONS

United Utilities (UU) is in a position of low water stress however over the next 25 years the company will have to invest in small to medium scale supply-demand schemes. WRMP methodologies require that all potential supply-demand schemes be compared on a like for like cost/benefit basis. Therefore UU has conducted a study into the effectiveness of domestic water efficiency devices. The project has been designed to investigate the potential costs involved in conducting an efficient large-scale scheme, as opposed to a project aimed to maximise water savings at any cost.

III CONCLUSIONS

The key results of the study regarding number of audits and devices fitted are shown in Table 1. The percentage of each device fitted indicates the proportion of households where at least one of these devices was installed.