Project appreciation and objectives
When Government consulted on options for encouraging water efficiency, respondents overwhelmingly supported the introduction of a whole building performance standard for new dwellings in the Building Regulations. This has been translated through the addition of a minimum water efficiency standard to the new edition of Part G of the Building Regulations which came into force in April 2010.
Water companies are required to forecast household water demand in their Water Resource Management Plans for the Environment Agency (SEPA in Scotland). This includes an estimate for the consumption from new dwellings built to meet the new water efficiency standard.
However, it is recognised that the Part G water efficiency standard is based on a number of assumptions and may not necessarily reflect the actual water consumed within new homes for a number of reasons, for example:
- Occupants may use their domestic appliances in different ways from that assumed by the Part G calculation methodology.
- Householders might replace the installed water-efficient products with less efficient versions over time.
The water industry has therefore identified a need to understand the true consumption of new homes built to the new Part G standard. This information will allow water companies to better forecast water consumption from new homes for their Water Resource Management Plans.
Benefits to Clients
The project will:
- Improve the evidence base for demand forecasting of water consumption in new homes build to Regulation 17K (Part G).
- Help to understand the role of occupancy on water consumption in new homes.
- Ascertain whether regional or local factors are important in determining water consumption in new homes.
- Obtain customer attitudes on water using devices installed to determine their level of satisfaction.
- Ascertain if a more detailed understanding of water consumption in new homes is needed to aid demand forecasting.
By working collaboratively, the participants will benefit by:
- Allowing companies to obtain results on a larger sample of households whilst carrying out monitoring only in their area.
- Minimise uncertainty in the results at minimal cost to each company.
The work proposed will be staged in two phases. The first phase is designed to allow an estimation of per household and per capita consumption for a range of new property types and occupancy rates.
The following tasks will be carried out under Phase 1:
- Task 1 - Sampling Framework
- Task 2 - Liaison with Developers
- Task 3 - Data collection and collation
- Task 4 - Data Analysis
- Task 5 - Satisfaction Questionnaire
- Task 6 - Reporting
Dependent on the results of this phase, a second phase will be designed to investigate any differences found amongst the sample monitored in phase one. The objectives for a phase two study will be agreed following analysis of the results from phase one.
The project outputs are as follows:
- Report detailing methodology and results of household monitoring.
- Proforma customer satisfaction questionnaire.
- Group meetings to review approach and discuss progress with peers and experts.
Related WRc Work
- Revision of Part G of the Building Regulations, CLG, 2007-2009.
- Organisation and presentation of Part G Building Regulations workshops, 2009.
- Analysis of consultation responses for water efficiency in new and existing buildings, CLG, 2006-2007.
- Market Transformation Programme (MTP), DEFRA, 2006 - 2009.
- Reducing Water Consumption in Buildings, ODPM, 2004 - 2005.
- Micro-component-based forecasting for the AMP5 WRP, STW, 2006 - 2007.
- Various water use and water efficiency projects, 1999 - present.