Water consumption calculations

Water consumption calculations

It is a requirement of Approved Document G of the Building Regulations that all new dwellings (including those created through a material change of use) must achieve a projected water consumption of no more than 125 litres per person, per day.

The projected water consumption is to be calculated in accordance with the methodology set out in The Water Efficiency Calculator for new dwellings.

We can provide you with a copy of the calculations required for compliance with Approved Document G. Furthermore, to ensure every dwelling achieves a pass we will advise you on the minimum acceptable efficiency for each fitting.


How Energytest can help

Fast and accurate water consumption calculations at a competitive price.

Comprehensive advice and support to ensure you arrive at the most economic and feasible solution to achieve compliance.

One fully-inclusive fee covering:

  • Water consumption calculation.
  • Building Regulation certification.
  • All the consultancy required to ensure every dwelling achieves a pass.

Single-source-solution for Building Regulation compliance. As well as your water calculations we can provide:

Factors that affect the calculated water consumption of a dwelling include:

  • The flow rate of showers and taps;

  • The capacity of baths;

  • The flushing capacity of WCs;

  • The consumption per place setting of dishwashers;

  • The consumption per kilogram of dry load for washing machines;

  • The efficiency of water softeners (where present); and

  • Whether there is any on-site rainwater or greywater harvesting.

If the fittings have not yet been purchased or installed we shall advise on a minimum efficiency required to achieve a pass.

If the dwelling is already fully fitted-out there are still options to achieve compliance. We can advise on all available options to meet your requirements.

What our clients say:

“We have used Energytest for a few years and have been very impressed with their knowledge and efficiency. Andrew, Sam and Wilson are very approachable, friendly and good at their job. Queries are answered quickly and we appreciate Energytest’s ability to produce results, even at short notice. The team have been particularly helpful guiding us in what information to provide for Water Calculations and getting certificates back to us promptly. We look forward to maintaining a positive and productive relationship with Energytest in the future.”

A Stoney – Cura Construction Ltd