Water Efficiency Calculations

Do you need to provide water efficiency calculations planning or Building Regs?

Build Energy can provide quick, easy and bespoke reporting to get you through – whether you need water efficiency calculations for Part G regulations, or the equivalent level for planning reporting.

Why Do You Need Water Efficiency Calculations?

Building regulations demand that you meet the minimum 125 litres per-person-per-day limit. But if the development is subject to a planning condition, you may also be required to reduce internal potable water use to 110 liters. This is at the discretion of the local authority.

This is demonstrated by producing calculations, based on occupancy, fittings and flow rates within the water efficiency calculator.

Be Efficient - Water

A number of measures can be taken to reduce indoor water use. Flow restrictors are a convenient means to retrofit existing fittings. Low flow shower heads, low flush wc’s or even smaller baths may be fitted.

Efficient appliances, grey water and rainwater recycling can also be specified. We can suggest solutions and products which are efficient, practical and cost effective.

The Water Efficiency Calculator for New Dwellings

Our bespoke water efficiency calculations are based on “The Water Efficiency Calculator for New Dwellings” – The Governments national calculation methodology. This provides clear, concise information for both you and Building Control including:

  • Notice of Water Efficiency (as required by 37(1)
  • Summary page together with all corresponding completed tables
  • Separate “Design” (including Builders check list) and “As Built” Reports

Need help with Water Efficiency Calculations?

Just call us on 01202 280062 or send us your enquiry


Build Energy have been quick to provide a helpful and efficient service in several projects......their willingness to provide advice and first-class service exceeds expectations. We have had pleasure in dealing with the team in the past, have recommended their services to others and would do so again without hesitation........we look forward to a continued relationship in future projects

Mark Warburton – Commercial Director, BeSpace Urban Design