Department for Communities and Local Government

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• Good practice and guidance
• The Water Efficiency Calculator for new dwellings

Planning, building and the environment

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Summary

This document sets out the Water Calculation Methodology for assessing the whole house water efficiency of new dwellings.

The latest document is the September 2009 version and replaces the previous May 2009 version.  

The calculation method is to be used to assess compliance against the water performance targets in Building Regulations 17.K and the Code for Sustainable Homes now uses this calculator as the Assessment Methodology for WAT1.

The Water Calculator tool (Excel spreadsheet) is available below to download free.

Note: The Calculator is not a design tool for water supply and drainage systems. It is also not capable of calculating the actual potable water consumption of a new dwelling. Behaviour and changing behaviour can also have an effect on the amount of potable water used throughout a home.

Order

• This publication is only available online - see below to download.

Download

• Water Efficiency Calculator
  MS Excel , 4443 kb , 10 pages
• The Water Efficiency Calculator for new dwellings (external link)
  PDF, 1600 kb , 23 pages

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Alternative formats

If you require this publication in an alternative format (eg Braille or audio) please email alternativeformats@communities.gsi.gov.uk quoting the title and product code/ISBN of the publication, and your address and telephone number.

Related publications

• Code for Sustainable Homes: Technical guide - 2010

  • Published: 11 November 2010
  • Site: Planning, building and the environment

• Mandating Water Efficiency in New Buildings - A Consultation

  • Published: 13 December 2006
  • Closing date: 8 March 2007
  • Site: Planning, building and the environment