www.water-efficient-buildings.org.uk Water efficiency in new developments: A best practice guide Acknowledgments Contact us Waterwise East would like to thank the project group for Please direct questions and comments to the website www.water-efficient-buildings.org.uk on which [email protected] this guide is based. Their work has enabled this guide to or phone +44 (0)845 257 1667. be put together. The project group included representatives from Waterwise East, Anglian Water, BRE, ECD Architects, Copyright and disclaimer GROHE, Carron Phoenix and Essex and Suffolk Water. Effort has been made to ensure the accuracy of the content of this report, as well as the reliability of the analyses We are also very grateful to the sponsors of the site: the presented. Waterwise accept no liability for any actions East of England Development Agency, the Environment taken on the basis of the contents of this report. Agency (Anglian Region), Anglian Water and Cambridge Water Company for their continued support. © Copyright 2010 The Waterwise Project. All rights reserved. Authorship This guide was written by Clare Watters, Waterwise East Co-Ordinator and builds on previous work by her predeces- sor Andrew Pitt and the website project group. There was input from Jacob Tompkins, Managing Director of Waterwise and Victoria Higgins, Waterwise Communications Executive, who edited this guide. 1 Queen Anne’s Gate London SW1H 9BT About us United Kingdom Waterwise is an independent, not-for-profit, nongovern- T: +44 (0)207 344 1882 mental organisation focused on decreasing water con- E: [email protected] sumption in the UK, and on building the evidence base for large-scale water efficiency. Our aim is to reverse the www.water-efficient-buildings.org.uk upward trend in how much water we all use at home and www.waterwise.org.uk at work. We are developing a framework supported by a robust social, economic and environmental evidence base to Published April 2010 demonstrate the benefits of water efficiency. To achieve our aims we work with water companies, governments, manu- facturers, retailers, non-governmental organisations, regu- lators, academics, agricultural groups, businesses, domestic consumers, the media and other stakeholders. We conduct our own research and also undertake work as consultants. Waterwise East is the regional centre of excellence for water efficiency in the East of England. It aims to reduce water wastage in the region and is primarily focused on develop- ment and the built environment. We support the delivery water-efficient developments by working with develop- ers, planners, housing associations, local authorities and other water stakeholders to improve their water efficiency knowledge and encourage sharing of best practice. We also work with other water stakeholders encouraging them to uptake and promote water efficiency. Contents Introduction 2 Regulation – government intentions and policy direction 3 Part G of the Building Regulations 3 The Code for Sustainable Homes 3 Water Efficiency Calculator 4 The cost of achieving water efficiency 6 Achieving Code levels 1 and 2 6 Achieving Code levels 3 and 4 6 Achieving Code levels 5 and 6 6 Householder savings 6 Energy and carbon savings 6 Home buyer and public attitudes to water-efficient products 7 Waterwise East and Savills research, 2009 7 Strategies for whole-building specification 8 Fittings-based strategies 8 Recycling-based strategies 8 Bathroom manufacturers 8 Fittings and appliances 9 WCs 9 Showers 9 Baths 10 Taps 10 Washing machines 10 Dishwashers 10 Water softeners and conditioners 11 Waste disposal units 11 Water recycling systems 11 Greywater recycling systems 12 Rainwater recycling systems 12 Sustainable Drainage Systems (SuDS) 13 Outdoor water use 14 Water pressure and design considerations 15 Water pressure 15 Implications of boilers and water recycling on water pressure 15 Plumbing system design –efficiency considerations 15 Developer interaction with water companies 16 Contact details 16 Case studies 17 Introduction In the past three years, over 10,000 new homes www.water-efficient-buildings.org.uk was launched by have already been built to improved water efficiency Waterwise East in June 2009. This contained “The Design standards in the East of England with the support of Guide for Developers” which is useful for developers and Waterwise. This leaflet explains some of the consider- housing associations building to any Code level with its ations needed when building a water-efficient home associated water efficiency requirement. This leaflet sum- or development. marises current best practice for those wishing to build new water-efficient developments. Despite having a seemingly wet climate, parts of the UK are experiencing water shortages, with some areas in England www.water-efficient-buildings.org.uk provides a valuable having less water available per person than Sudan and Syria. source of information about costs and benefits of water- Water efficiency is vital to accommodate new developments efficient new development, as well as advice on the speci- while protecting our rivers, wetlands, lakes and broads. Up fication and delivery of water-efficient developments. It is until 2030 the overall picture in the UK is one of ever-in- therefore relevant to policy and decision makers, for example creasing demand for an ever scarcer resource, and less water helping deliver the government’s Future Water ambition of will need to go further. 130 litres per person per day by 2030, and to make all homes zero carbon by 2050. The government is driving a sustainable development programme that mandates improved water efficiency in This guide will assist developers, facility managers and the built environment, including the Code for Sustainable landlords to improve the water efficiency of new dwellings. Homes (Code) and Part G of the Building Regulations. In addition, improved water efficiency in new development will be supported through the planning system. Disclaimer Many elements of this guide are susceptible to change, particularly those depending on policy and regulation. This document uses information that was correct as of March 2010. All the information in this guide and more detailed, up-to-date information is available from www.waterefficientbuildings.org.uk 2 Water efficiency in new developments – a best practice guide Regulation – government intentions and policy direction Against a backdrop of climate change, energy supply The Code for Sustainable Homes security and the need for more housing, the govern- The Code is the government’s main tool for improving the ment has outlined its strategy to improve the environ- environmental specification of new homes. All new homes mental performance of the built environment. In terms are required to be assessed against the Code, with a Code of new dwellings the following standards are driving or nil-rated certificate included in the Home Information water efficiency: Pack. All new homes built with public money must meet at least Code level 3 from April 2008. The Code is also the Part G of the Building Regulations national standard most often used by the planning system The government updated Part G of the Building Regulations to mandate water efficiency for new housing developments in April 2010. This revision sets a whole-building standard of in their area. 125 litres per person per day for domestic dwellings, com- prising internal water use of 120 litres per person per day There are seven Code levels ranging from level 0 (Building (in line with Code levels 1 and 2), plus an allowance of five Regulations) to level 6 (zero carbon). To achieve the Code litres per person per day for outdoor water use. This is to levels, points are awarded for achieving set standards in be specified using the methodology set out in “The Water nine different aspects of development. Water consump- Efficiency Calculator for New Dwellings” also used for the tion inside the home is one of the compulsory aspects of Code (see pages 4 and 5 for more information on the cal- the Code and up to five credits are available for perfor- culation). mance which reduces the amount of potable water used in the dwelling. The water consumption specification for increasing Code levels are: Table 1: Per capita daily water consumption specification of the Code for Sustainable Homes category WAT1 (CLG 2009)1 Water consumption Credits Mandatory Levels (litres/person/day) 120 l/p/day 1 Levels 1 and 2 110 l/p/day 2 105 l/p/day 3 Levels 3 and 4 90 l/p/day 4 80 l/p/day 5 Levels 5 and 6 Default Cases None Daily per capita consumption (PCC) of water is calculated using the Water Calculator (see overleaf) The Technical Guide for the Code is available from www.water-efficient-buildings.org.uk 1 Communities and local government, “Code for Sustainable Homes Technical guide May 2009 Version 2”, 2009, www.planningportal.gov.uk/uploads/code_for_sustainable_homes_techguide.pdf Water efficiency in new developments – a best practice guide 3 Water Efficiency Calculator Multiple fittings The Water Efficiency Calculator for New Dwellings (Water Where two or more of the same appliances are installed Calculator) is the government’s national calculation method which have different water consumption rates, the average for the assessment of water efficiency in new dwellings. flow rate/volume should be calculated, along with a pro- The calculator assesses the contribution that each internal portionate (also referred to as “weighted”) average of water fitting (micro-component) has on whole-house the highest consuming fitting (proportionate average is water consumption. calculated by taking the flow rate/volume and multiply- ing by 0.7). Where the proportionate average is higher The Water Calculator requires figures for water consumption, than the average, the proportionate average must be which should be provided in manufacturers’ product details. used in the Water Calculator (see Table 2 for an example Where product consumption is dependent on flow rates (for multiple fitting calculator for taps).