Part G Water Efficiency Calculations

Under Part G of the Building Regulations all new homes are now required to comply with water efficiency targets, this means that your building control body will now require you to provide calculations demonstrating that your proposed dwelling can function at a level of water consumption of less than 125 litres of potable water per person per day.

In order to comply with these regulations designers and developers will now have to give careful consideration to the sanitary ware, plumbing fittings and white goods to be installed in the dwelling.


Flow rates of plumbing fittings including taps and shower valves along with bath sizes, WC cistern flushing volumes and water usage by dishwashers and washing machines etc will all need to be considered in combination to calculate resultant water consumption.

Consideration may also be given to Rainwater harvesting which can have a significant effect on the reduction of potable water consumption.

I can provide you with all the necessary calculations and reports required by your building control authority including design stage information which will form part of your specification and should ensure that all resultant sanitary ware and plumbing purchases are compatible with the regulation target of 125 litres per person per day  .