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Water Efficiency Calculations

Updated: Jul 5, 2019


New Buildings ✔

Residential Sector ✔

Planning Stage ✔

Design Stage ✔

Post-Completion ✔

Part G of the Building Regulations outline targets for the water efficiency of white goods and fittings in our homes. New homes in England must be designed to use no more than 125L of water per person, per day.

Some Local Authorities may reduce this target to 110L to conserve water in low supply areas over the summer, and in Wales the limit is always 110L. Other circumstances which affect this limit include BREEAM or HQM requirements, as well as client or infrastructure restraints.  

Water Efficiency Calculations consider the flow rate of showers and taps, and the size of bathtubs and toilet flushes. White goods such as dishwashers and washing machines, and rainwater harvesting systems are also taken into account. These calculations define the limiting flow rates and volumes for the sanitary ware, therefore determining the type of fitting or imposing the use of flow restrictors.

Your designs must equal or improve upon the water efficiency targets set out by your Local Planning Authority to ensure compliance. We can help you from the very get-go with our team of experts poised to assist with calculations, reports and strategy.

Call our Leeds office on 0113 257 7300 to arrange a consultation with our Sustainability Team, or email for further information.

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