Part G - Water Efficiency

Part G - Water Efficiency

Building Regulations Part G - Water Efficiency

To coincide with the energy efficiency targets set for domestic housing, water conservation must comply with Approved Document G of Building Regulations for England and Wales - Sanitation, hot water safety and water efficiency.


Under Building Regulations Part G the water consumption should be no greater than 125 litres/person/day and the water usage for a dwelling should be calculated in accordance with the ‘Water Efficiency Calculator for New Dwellings.'


It is possible that the planning body can require the water consumption target to be no greater than 110 litres/person/day.


Ensure that communication is maintained on what the building control and planning boards requirements are as it is critical in determining if the property passes.


To complete a water efficiency calculation, we require full plans of the development being assessed, and for those plans to include bathrooms, kitchens, utilities and any wet room where running water is being provisioned.


The exact make and model of each fitting used is required so that the consumption rates can be taken from their spec and contribute to the calculation.


What is most directly taken into account?

  • Bathroom Taps
  • Dishwashers
  • Washing machines
  • Bath volume
  • Shower
  • WCs
  • Kitchen taps
  • Utility taps


Also taken into account:

  • Water softeners
  • Waste Disposal Units
  • Rain/Grey Water Harvester


Fittings can be used to reduce the flow of water or diffuse the output such that the water is at sufficient pressure to be practical but within the regulation’s consumption targets.


Ashby Energy Assessors have fully trained staff who can provide clear and concise design specification at the start of your project to ensure building control sign-off once the building is completed.

Get a Quote

Share by: