• 5 available credits
• Credits worth 1.50% points each
• Mandatory Element: Yes

Aim: To reduce the consumption of potable water in the home from all sources, including borehole well water, through the use of water efficient fittings, appliances and water recycling systems.

Assessment Criteria:

Full WAT1 2010 Issue

• 5 available credits
• Credits worth 1.50% points each
• Mandatory Element: Yes

Aim: To reduce the consumption of potable water in the home from all sources, including borehole well water, through the use of water efficient fittings, appliances and water recycling systems.

Credits are awarded based on a whole house assessment of the efficiency of internal water fittings against a benchmark figure. The assessment is measured in litres per person per day using the Water Efficiency Calculator for New Dwellings. The table below gives details of the required performance levels:

Full WAT1 2009 Issue

BS EN 12056-3 – Gravity drainage inside buildings – Roof drainage, layout and calculations (2000)

BS8515:2009 - Rainwater harvesting systems. Code of practice

BSRIA Technical Note TN 7/2001

Communities and Local Government

CIBSE TM13, 2002, Minimising the risk of Legionnaire’s disease

CIRIA Publication C539, 2001: Rainwater and Greywater Use in Buildings – Best Practice Guidance

EN200:1992 Sanitary tapware. General technical specifications for single taps and mixer taps (nominal size 1/2) PN 10. Minimum flow pressure of 0.05 MPa (0.5 bar)

Environment Agency, Conserving Water in Buildings 4: Rainwater re-use

HSE, 1999, Approved Code of Practice and Guidance L8

The Met Office (including figures for UK rainfall)

Increasing the Value of Domestic Wateruse Data for Demand Management Summary Report P6805, CP187, March 2005

Additional information:

Office of the Deputy Prime Minister, Housing Quality Indicators Form (version 2)

EN997: Compliance with water regulations for WC’s

Environment Agency: Assessing The Cost Of Compliance With The Code For Sustainable Homes WRc Ref: UC7231

HMSO, 1999, Water Supply, (Water Fittings) Regulations, 1999. Statutory Instruments

Market Transformation Programme, BN DW BATHS: Bath design and efficiency – Briefing Note relating to Policy Scenario Objectives in Policy Brief

Office of the Deputy Prime Minister, Buildings Regulations Approved Document H – Drainage and waste disposal, (2002)

Water Industry regulations, England and Wales No. 1148

Water Industry regulations, England and Wales No. 1506

BRE IP 1/04, ‘Drainage design for buildings with reduced water use’

Environment Agency National Water Demand Management Centre. Conserving Water in Buildings (2001)

Market Transformation Programme, BNWAT02: Domestic baths specification and stock model information

Water Regulations Advisory Scheme. Information and Guidance Note 09-02-04. Reclaimed Water Systems. Information about Installing, Modifying or Maintaining Reclaimed Water Systems (1999)