Part G - water efficiency calculator

There is a requirement in Regulation G2 that fittings such as taps and fixed appliances, such as washing machines installed in new dwellings will be water efficient to prevent undue consumption of water. The potential consumption of wholesome water by persons occupying a dwelling must not exceed 125 litres per day. This applies to newly erected dwellings or new dwellings brought about by a change of use such as conversion of a house into dwellings. The regulations require the person carrying out the work to notify the building control body of the calculated potential consumption. The estimated water consumption of a new dwelling should be calculated in accordance with the methodology set out in the ‘Water Efficiency Calculator for New Dwellings’. This is published by CLG Publication and is available on line at the following address. http://www.communities.gov.uk/publications/planningandbuilding/watercalculator
There is software available which can be used to assist you in the calculation. Some sites such as WRc PLC provide free on line software that can be used to carry out the calculation for you. Other sites provide software that you can pay to download. The link to WRc is provided below.
http://partgworkshops.wrcplc.co.uk/water-efficiency-calculator.html