Water Efficiency Calculations

Water efficiency calculations for new builds

Water efficiency calculations For Your Code Or Building

As part of Approved Document G fo the UK building regulations, new dwellings are required to meet strict standards for water efficiency, hot & cold water supply, and other water systems. Water efficiency calculations look at the different water sources in a building, such as kitchen taps, toilets and washbasins to determine the amount of water is supplied to the building through usage.

At Briary Energy, we can provide you with quick and easy reporting that will help to get you through. It doesn’t matter whether you need someone who can provide you with your water efficiency calculations or whether you need someone who can handle your Part G calculations for you, because we can do it all and more and at a price you know you can afford.

All of our water efficiency assessments are calculated using the UK Government’s official water efficiency calculator for new dwellings, so you can trust that the calculations will be accurate and give you a clear understanding of how the building meets water usage standards.

Why Do You Need Water Efficiency Calculations?

Building regulations all state that you need to meet the requirement of having 125 litres per person and every day. If the development is subject to the code for sustainable homes then you will need to reduce your internal portable water use even further through the Wat 1 category. Every single code has a limit on the water consumption you have and this is clearly demonstrated through applications that are based on the flow rates and the occupancy. The limits are set out as follows.

  • Less than 120L per Day- Level 1 and 2
  • Less than 150L per Day- Level 2 and 3
  • Less than 80L per Day – Level 5 & 6

There are credits available to you if you do happen to meet these targets. Of course, a number of measures can be taken if you want to reduce your water use. Flow restrictors are a great way for you to retrofit your fittings. You can have low flow shower heads and even smaller baths. You can also have efficient appliances and grey water/rainwater recycling.

Water Efficiency Assessments for New Homes

Our calculations are all based on new dwellings. The government uses a calculator to provide you with very clear and concise information and this is a great way for you to truly reap the benefits of everything that it has to offer. Our water efficiency assessments are carried out by qualified experts, which provide you with:

  • Notice for Water Efficiency
  • Summary w/ Corresponding Tables
  • Separate “Design” and “As Built” Reports
  • Code For Sustainable Homes Wat 1

Related SAP Calculation Services

Water efficiency also plays a role in SAP Calculations for new dwellings, due to things such as hot water usage affecting the energy efficiency of a property.


Contact us today to talk about your upcoming project – it could save you on average £800* per plot!