CONNECT WITH MSAFE 0333 8000 700 0

Water Calculations (Part G)

Water efficiency calculations

Calculating your consumption of water

Parts G of the Building Regulations require a water efficiency calculation to be carried out for all new dwellings. The calculation is to show the potential consumption of wholesome water per person per day. The calculations are based on fixtures & fittings in a dwelling and also any grey water or rainwater harvesting technologies that may have been utilised. Each dwelling is required to have a maximum consumption of 125 litres per person per day (l/p/day). 

Your development may even be required to achieve lower usage if built under The Code for Sustainable Homes:

  • Levels 3 & 4 ≤105l/p/day
  • Levels 5 & 6 ≤80l/p/day

MSAFE carry out all Water Calculations in accordance with the Government’s national calculation methodology The Water Efficiency Calculator for new dwellings.


To arrange a competitive fee proposal please contact MSAFE on 0333 8000 700 or fill in your details using the form and we'll call you back.

Industry News