Part G Water Calculations

Part G Water Calculations

What is the Part G Water Regulation?

Building Regulations require that new dwellings meet the minimum 125 litres per-person-per-day of potable (safe to drink) water.

If the development is subject to a planning condition, you may also be required to reduce internal potable water use further, often to 105 litres; this is at the discretion of the Local Authority.

What are Water Calculations?

Since 2010, Approved Document G – Sanitation, hot water safety and water efficiency, has required that all construction projects, whether that be an extension, conversion or new build, are water efficient enough to supply this 125 litre per person minimum threshold.

Part G water calculations take into account:

  • Taps
  • Toilets
  • Baths
  • Showers
  • Other water producing appliances including dishwashers and washing machines