key performance indicators for water use in · pdf filekey performance indicators for water...

February 2006

Key Performance Indicators for water use inoffices

Rachel Waggett Faber Maunsell

Catherine Arotsky Rickaby Thompson Associates

Classic House, 174–180 Old Street, London EC1V 9BP TEL +44 (0)20 7549 3300 FAX +44 (0)20 7253 0523 EMAIL [email protected] WEB www.ciria.org

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CONTENTS

1. Introduction 3

2. Office water conservation 5

3. References 26

4. Acknowledgements 26

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1This document is a simple guide to checking whether the water consumption of an office is high or low compared to theaverage. It also provides some guidance about how to improve water consumption to reduce water and sewerage bills, andprovides signposts to more detailed advice.

Research has shown that office buildings that do not have any water conservation strategies or equipment can save up to 50per cent of their total water use by implementing simple measures .

This guidance has been produced as part of a project that aimed to:

provide building owners, facility managers, building engineers and designers with information to help thembenchmark water efficiency in office environments

help improve water efficiency and encourage the sustainable use of water within buildings.

It is intended to be used by those who can have an influence on water use in offices, including landlords, office managers andbuilding owners. It will be particularly useful for those who have noticed their water bills are higher than anticipated, or thosewho are considering refurbishments or planned maintenance.

Much guidance exists on good practice management of offices, all of which is based on the foundation of a good managementsystem:

1 Measuring consumption.

2 Making alterations to try to reduce consumption.

3 Monitoring changes in consumption over time.

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CIRIA EVIRONMENT AGENCY OFWAT DWR CYMRU BOURNEMOUTH AND WEST HAMPSHIRE WATER SOUTHERN WATER ESSEX AND SUFFOLK WATER SOUTH WEST WATER SCOTTISH WATER VEOLIA WATER

Introduction

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This applies to all types of resource use in offices, including water use, and is encouraged by the guidance provided in thisdocument. The indicated benchmarks fit into this cycle of continual improvement – they allow managers to determinewhether the water consumption that has been monitored is too high or acceptable, and if too high, to initiate changes.

Signposts to more detailed information and advice on improving performance are provided throughout the guidance, butexcellent advice on water conservation can be obtained from:

local water companies – there is usually a number to call for advice shown on the water bill, or local phonelistings and books will show the water company

Environment Agency – the Agency has a great deal of information on water conservation, and on appropriateproducts that can be installed to save water. Much of this information can be found on its websitewww.environment-agency.gov.uk/savewater

Further details about the research that underpins the benchmarks and the background to the project are provided at the endof the guidance.

2Why conserve water? – to save your company money and benefit the environment.

find out how much water your office uses – 2.1–2.3

compare with the benchmarks – 2.4, 2.5

check for anomalies – 2.6

consider ways of reducing consumption – 2.7.


At a glance

Office water conservation

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Many office buildings in the UK use much more water than they need to, leading to higher than necessary costs andenvironmental impacts. Water use in offices can be reduced both by influencing user behaviour and replacing older or faultyfittings. Often measures can be taken that cost little or nothing to implement, but result in immediate bottom line benefits. By reducing water use, both water and sewage bills will decrease and could result in a considerable saving.

Office buildings differ in the facilities they include, but a typical consumption pattern is shown in Figure 2.1, with the greatmajority of use accounted for by the washrooms. The biggest single determinant of total use is likely to be the number ofpeople working in the office. Their education in water use will, therefore, be an important issue, as well as the type of fittingsinstalled and their maintenance.

Figure 2.1 Water use in offices


2.1. Does your office use too much water?

The first step in reducing water use is to monitor consumption, which can be read from the water bills in terms of cubicmetres (m3 ) used during the billing period. This is a simple process if you occupy the whole building and pay the bills directly,but can still be accomplished if you occupy part of the building or if the landlord pays the bills – see Section 2.6.

For benchmarking purposes the figure should be converted to cubic metres per year and for best results you should:

use figures for at least one complete year, and preferably several years,s to take account of potential seasonalvariations

rely on actual rather than estimated readings (usually indicated by an ‘E’ next to the figure on the bill)

check the readings yourself on a regular basis – this ensures that you are being correctly billed!

If the bills cover a period that is not exactly one year, it may be easier to calculate how much water the office uses per day –read Section 2.3 for more details in this case. If you have missing bills, ask your water company for a reprint of the bill.

2.2 Converting into standard formats

To make the water use comparable with other offices, it needs next to be converted into a standard format. This can be doneeither per employee or per square metre.

Which of these two factors will be best for you will depend on the type of business you have – if the number of people in theoffice tends to be very variable (eg staff often absent on business, or large numbers of part-timers), then you may find itbetter to use a floor area factor. However, if your staff are based mainly at the office, or the office has few occupants for thespace you occupy (such as a small office within a larger warehouse), it would be better to use the employee factor.

For an employee figure, use the total number of employees in your business, apart from those people who are out ofthe office for most of the time, such as sales representatives. Divide the total annual water consumption figure obtainedfrom the water bills by this employee figure to obtain your water use per employee per year.

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For a square metre figure, use the net lettable floor area of your office in square metres if possible. Divide the totalannual water consumption figure obtained from the water bills by this floor area figure to obtain your water use persquare metre per year.

If you have a figure for office area in square feet, it can be converted into square metres by dividing by 10.76 – forexample 9000 square feet /10.76 = 836 square metres (m2)

If you have data for more than one year, perform the calculation for each year, so that you can make comparisons betweenyears and track whether water consumption is generally increasing or decreasing over time.

2.3 Converting to litres per day

Showing a figure in cubic metres per year is useful for benchmarking purposes, but it can be very difficult for people toenvisage how much this means is being used in practice. Since the point of carrying out benchmarking is to encourage peoplein the office to save water, it can be useful to convert the figures into a more tangible format, such as litres per day.

To convert the figures above into litres per day:

1 multiply the water use in cubic metres by 1000, to convert it to litres

2 divide this figure by 253 (the number of ‘standard business days’ in a year, excluding weekends and bankholidays)

This will provide you with a figure of either litres per day per square metre, or litres per day per employee, depending onwhich factor you chose originally. If you know that your office is occupied for a different number of days than 253 per year,then use your figure instead in the calculation, making the comparison more accurate. You can then use any of these figures tobenchmark your office, by comparing it with the charts below.

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2.4 Benchmark water use per square metre

If you used a figure for office area in square metres, use the chart below to compare your water use.

Fig 2.2 Water use per square metre

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2.5 Benchmark water use per employee

If you calculated your water consumption by number of employees, use the chart below to compare your water use.

Fig 2.3 Water use per employee

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2.6 What if…?

? What if different years show different results?

If you have several years’ water use with different water use figures, this is probably because there has been a change in howyour office is managed during this time. Consider the figures in more detail, and ask managers about possible changes. These could include:

refurbishment of washrooms or installation of new facilities such as a staff canteen

change in number of employees or floor area taken by the company

re-adjustment or fitting of automatic controls, such as urinal controls.

However, different figures could also indicate a new leak or a leak being fixed.

Remember also to check that you have not included estimated figures from your bills.

? What if the water bills are paid by the landlord?

This is very common in UK offices, but even if you pay a service charge rather than direct water bills, you can still compareyour water use as long as you have a water meter. You could ask your landlord for copies of the water bills, or alternativelycheck your water meter on a monthly basis for totalling over a year and using as above. This will also allow you to track waterconsumption during different months, and identify which months have the highest consumption. This may give you some cluesabout where most of the water is used. It may even allow you to negotiate a reduction in your charges with the landlord.

? What if the office is shared by more than one company?

If your office only has one water meter but more than one company within the office, it is still possible to compare yourwater use. At a simple level it may be possible to estimate your water use by dividing it between the different companies byfloor area within the building. This would not be as accurate but would provide an outline indication. The best method is toinstall a sub-meter to your area so that you can read your water consumption from it. You could also talk to the othercompanies’ representatives about producing a building-level benchmark, from which you could all benefit.

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? What if my water use is very low?

Congratulations! If your water use is very low, your company is very efficient at using water and probably has up-to-dateappliances and fittings as well as staff who understand how important it is to save water. But if this doesn’t sound like yourbusiness, then check that your water meter is taking readings accurately – sometimes they need servicing or refurbishing bythe water company, particularly if they are rather old. This type of mistake is usually sorted out in the end, but you may saveyourself from a nasty surprise by checking yourself!

Alternatively, if you are taking readings yourself rather than using water company bills, maybe you have missed a meter!Sometimes buildings have more than one water meter, especially if they have been extended or refurbished in the past. For example, there may be separate meters to different core areas, or to the air conditioning systems.

Finally, make sure your figures cover a full year of operation, not part of a year. If you don’t have information for a whole year,try dividing the figures into litres per day (see Section 2.3).

? What if my water use is much higher than expected?

This will be the case for many businesses in the UK, but don’t worry, there are many measures that you can take to reduceyour water consumption. All will save you money and most have short payback periods – often less than a year. There arealso many measures that can be taken requiring no investment at all.

Before deciding to install a particular product the cost of installation and any maintenance will need to be taken into accountand balanced against the savings you might expect over time. Most manufacturers provide some information of this type, butmake sure that it is appropriate for your area of the UK – water costs differ from area to area, so manufacturers’ calculationsmay differ for yours. Before considering installing any new products or fittings, use the ‘no cost’ option of simply reducingwhat is wasted by raising awareness among all staff.

Look at the brief guidance provided in Section 2.7 and, if you want to know more about a particular suggestion, follow thelinks to find further information. The local water company is always a good place to start for advice and information on waterconservation and sometimes they provide free equipment that you can install straight away.

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2.7 How to reduce your office water consumption

Reducing waste

Often water can be wasted simply because staff are not aware of using too much water. A staff awareness campaign,highlighting the amount of water used in particular areas, can be very effective (the local water company may supply itemsfree of charge, such as stickers to place beside taps, reminding users to turn them off). It can also be extremely effective toask staff for suggestions on saving water. Because they use the equipment every day they will have the best understanding ofwhere water can be saved.

Staff may also know about systems that are wasting water due to a need for maintenance (such as scaled up taps) or poorinstallation (such as long, uninsulated pipe runs leading to a long wait for hot water).

Plugging the leaks

Check for leakage by monitoring how much water is used when the building is unoccupied. Check the water meter last thingat night, and again first thing in the morning (or if your office is 24 hour, at some other unoccupied time). Turn off anyautomatic flushing systems if you can. Remember to turn them on again the next day! If water is still being used, it mightindicate that you have a leak somewhere on the premises. Contact your water company who will advise you how toinvestigate this possibility.

Automatic flushing

Some automatic flushing systems (commonly urinals) flush throughout the day and sometimes throughout the night andweekends, whether they are used or not. This can consume huge volumes of water, most of which is wasted. If water use ishigh when the office is unoccupied, this might be the reason. Check the control system type and timings, and considerchanging timings or replacing the system with one that reacts to usage, eg a passive infra-red flush actuator.

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Case studyThe Environment Agency offices in the North West were found to be using more than 300 litres of water per hourwhen the office was unoccupied. When urinal controls were changed, this reduced to 10 litres per night 3 .

There are many types of urinal control that can be selected to ensure that urinals flush only after they have been used.If an office has no occupancy at night, a simple timing mechanism would result in an immediate improvement.

There are some urinals that use no water at all, being designed to work without flushing. These have been trialled andfound effective by many users. They can be installed in existing urinals or when installing new fittings.

For more information including suppliers of controls and urinals, a factsheet can be downloaded from:www.environment-agency.gov.uk/savewater (click on ‘Publications’ to find the factsheets.)

The UK Government assists with the cost of urinal controls by providing an Enhanced Capital Allowance on certainproducts. See www.eca-water.gov.uk for more details on eligible products.

Toilet water use

Fig 2.1 shows that most water in offices is used in toilets. The amount of water that the toilets will use depends on their age –if they are more than 10 years old, they probably use nine litres for each flush. Even if they are only five years old they can useup to 7.5 litres.

All toilets fitted after Jan 2001 must have a maximum of a six litre flush, and if a dual flush cistern, the smaller flush no morethan four litres. If you are refurbishing your washrooms, dual flush toilets which give users a choice between a full or half flushare a good choice and are available for visible or concealed cisterns.


Making a change

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If the toilets are not being replaced, consider reducing the flush artificially by installing a cistern displacement device (such as a‘Hippo’ or ‘Saveaflush’) or possibly a retrofit variable flush device. This will result in a reduced flush, but it is important toremove them if users find that they do not provide sufficient water volume – otherwise they may result in even more wateruse. Many water companies provide such devices at reduced rate or free.

In all cases it is very important that you check regularly that toilet cisterns and cistern devices are working properly and notleaking – see Maintaining water fittings, below. In addition, making a regular check that the cistern fill level is set correctly to themark, will ensure that excess water is not wasted, and that the cistern operates properly.

Cistern displacement devices were installed (with other water saving measures) at council offices in Kingston. Thewater use was reduced by 41 per cent as a result of these measures, saving more than £30 000 per year over a numberof offices 3.

Plan for replacement of toilets in advance, identifying the product you wish to use. If your landlord is responsible forwashrooms, talk to him about using water efficient toilets and other water-saving equipment. Make sure you combinethis with publicity for the measure in the office, letting users know that you have new toilets and how to use them,especially if you are using dual flush toilets or cistern displacement devices.

Further information and a suppliers list is available from the Environment Agency. A factsheet can be downloaded fromwww.environment-agency.gov.uk/savewater (click on ‘Publications’ to find the factsheets).

These technologies are also eligible for Enhanced Capital Allowances from the UK Government if certain products arechosen. See www.eca-water.gov.uk for more details.


Case study

Making a change

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Taps and showers

Washing accounts for 27 per cent of water use in typical offices as shown in Fig 2.1, so choosing the right fittings can have aconsiderable effect on water bills.

Taps that can be left on by users may be wasting many litres a day, and even dripping taps can mount up! Even low water usetaps, such as spray taps or push top taps, can lose water if they are poorly maintained, especially in hard water areas where theycan easily scale up. Many tap controls can be fitted to existing taps, if they are of the ‘pillar’ type, and cost very little to install.

Although you may have seen water conservation advice that recommends installing showers rather than baths, a powershower can fill the equivalent of a bath in only a few minutes – consider whether a power shower is really needed, andwhether a gravity or lower power version would be equally good.

When a planned refurbishment of the office washroom is due, select taps and showers that conserve water. Showerswith a restricted water usage such as nine litres per minute can be specified. These will still provide a good flow ofwater with reduced waste.

For hand basins choose a tap that has a restricted outlet with a good wash pattern. These will use much less water thanan open ended tap.

There are many different types of tap mechanism available, and some have other benefits, such as reduced risk ofscalding (from thermostatic mixer taps) and health and safety benefits (infra-red taps that are not touched by users).

Further information on both taps and showers can be obtained from the Environment Agency. A factsheet can bedownloaded from www.environment-agency.gov.uk/savewater (click on ‘Publications’ to find the factsheets),which includes details of suppliers and savings.

Tap controls are also eligible for Enhanced Capital Allowances from the UK Government for certain products, find outmore from www.eca-water.gov.uk


Making a change

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Canteens and kitchens

Even if your office only includes tea points rather than a canteen,it could still be using a lot of water. Most of the water used insuch areas depend on the users’ behaviour, such as filling sinksrather than washing up under a running tap. Make sure that allusers realise how much water they could save and that they areaware of ways to help.

The equipment within a kitchen will influence how much water isused. If the kitchen is equipped with a dishwasher, check thewater consumption of the model and the most efficient setting(this is usually included in the instructions that came with themachine). Most people use only one setting, so it makes sense tocheck that it is the most effective one!

Grounds maintenance

Many offices have little open space other than car parking areas,and so will not need to use water to maintain the grounds. It isusual to have a few plants around the reception area orinterspersed in the car park, and some offices have large areas ofgreen space that need maintenance.

The most important issue for grounds maintenance is to cutdown or eliminate watering of plants. It is possible to eliminatewatering altogether if the grounds and the planting are plannedcarefully, or to choose efficient watering systems if theyabsolutely must be watered. It is also possible to store rainwaterfor watering to cut down the amount of mains water that is used.


Waterconsumption isshown here

Fig 2.4 Where to look for appliance water consumption

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Making a change

Consider how water is used in the kitchen. If it is simply rinsing cups and spoons, the main water use will be therunning of taps. You could help users to reduce water by putting up labels (usually available from your water company)or by changing the taps to spray or push taps. However, these are not really suitable if you need to run a full sink, sothis does need to be discussed with the users first.

If you are specifying a new dishwasher, look at the energy label – this also tells you how much water the machine willuse on the ‘eco’ setting (see Figure 2.4). Dishwashers designed for eight place settings will use between 10 and 30 litresof water per wash, and full size (12 place settings) machines will use 10–50 litres. The more economical machinesactually use less water than two sinks of washing up, so if the office does not have a machine it may be worthpurchasing one

In commercial kitchens or canteens, the equipment used will be very different. In these situations it will be easier totrain the users to remember water conservation messages, since there are a limited number of people with access tothe equipment. Often the users themselves will come up with ideas for savings if they are asked!

Commercial dishwashers and glass cleaning equipment can be specified to minimise the volume of water used, andsome machines even reuse the last (clean) rinse water in the next pre-wash. Tell your commercial supplier that you areinterested in products that save water and ask what is available.

There is further information on dishwashers and kitchen taps, including suppliers lists available from the EnvironmentAgency. A factsheet can be downloaded from www.environment-agency.gov.uk/savewater (click on ‘Publications’to find the factsheets).

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Making a change

When choosing new plants, select those that are hardy and need little watering. Make sure they are mulched properlyeach year to cut down evaporation and have sufficient space to put down a good root system to gain access to naturalwater (don’t keep them in small pots if at all possible). Hanging baskets use a lot of water so try instead to chooseplants in ground level planters where the roots can penetrate into the ground to find water. Consider whether adifferent type of space would provide the same professional look with less maintenance – such as a gravel covered arearather than lawn, for example.

Gravel provides an excellent mulch. This will also reduce maintenance time.

If it is necessary to irrigate the plants, firstly consider whether you can do this using a rainwater butt and a wateringcan. If rainwater is being stored on site anyway (perhaps to reduce water runoff) then consider whether this watercould be used. This has the advantage of using non-mains water so there will be no cost for the water.

If you do need to use mains water, make sure you choose the right system. Sprinklers are very high consumers of water(using as much in just one hour as a family of four uses in one day) and they usually don’t water the grounds mosteffectively. The best systems are automatic systems that deliver water straight to the plant’s roots only when required,by using both a timer and a moisture sensor in the soil. This means that the plants will not be watered when it hasbeen raining, and it reduces maintenance time, as it is automatic. At the very least try to use a hosepipe with a triggermechanism, rather than a sprinkler, to save water running unattended.

Further information is available from the Environment Agency. A factsheet can be downloaded from www.environment-agency.gov.uk/savewater (click on ‘Publications’ to find the factsheets).

There is also plenty of information available on the internet regarding choices of plant and systems for low watergardening.

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Maintaining water fittings

The most efficient water fittings still need to be maintained if they are to work properly. This is particularly important in hardwater areas where taps and other fittings can scale up, causing them to stick ‘on’ or require longer use to get the same effect.

Set up a maintenance programme where each fitting is inspected six monthly and cleaned if necessary. This is also auseful time to inspect automatic controls such as urinal controls and irrigation equipment to make sure that the timingsetc are still appropriate and they are still working as intended.

At the same time, inspect all toilet cisterns and automatic controls to ensure that they are still in good working order.This is still necessary even if the systems are relatively new. For example, some new style toilet cisterns have valvemechanisms that use a seal which must ‘seat’ properly if it is to work. Sometimes these seals can become blocked orcan fail to seat, causing a continual slow leak into the toilet – often unnoticeable unless the seal is checked regularly.Considering how such cisterns and other devices needing maintenance will be checked and accessed when they arepurchased will save a great deal of time and disruption in the future, particularly for concealed types.

Make sure you ask staff if they are having any problems – including systems that may have stopped working properly, orwere perhaps not fitted well to begin with. One common problem is hot water that takes a long time to reach thepoint of use – an instantaneous heater or better insulation of the pipework might be a good solution.

If you are not responsible for the maintenance of fittings, make sure that you report all problems as soon as possible tothe landlord or estate manager, and encourage all users to report difficulties before the difficulties become worse.Encourage users to come up with ideas for water savings too – they are more likely than you to know how they canchange their behaviour!


Making a change

3CIC. Water Conservation in Business. A briefing guide for Construction Clients and Building owners. Construction IndustryCouncil, London, Undated.

Griggs, J, Shouler, M, Hall, J. 1996. Water Conservation related to the built environment. In: Proc. of Water Conservation and ReuseCIWEM Conference 1996.

Saving Water – on the right track. Environment Agency 1998.

4This project was sponsored by the funders listed below. With the increasing requirement to safeguard water supplies in theUK and implement sustainable water use, it was recognised that there was a lack of suitable benchmarking information onwater consumption in the hotel and office sectors. The identification of benchmarks would allow a simple method ofcomparing the consumption of a particular property with national trends.

The main project report – Water – Key Performance Indicators and benchmarks for offices and hotels (CIRIA C657) – describeshow suitable benchmarks have been found for water use in offices and hotels across England and Wales that will enablemanagers of offices and hotels to understand whether their property is performing well or poorly in comparison with othersimilar buildings in the UK, and to inform designers about target usage. This guidance for the offices sector has been preparedfrom the findings of the main study.

Water key performance indicators and benchmarks for offices

Principal author: Rachel Waggett

CIRIA Publication W11 © CIRIA 2006

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References

Acknowledgements

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Research contractor Faber Maunsell

Steering GroupFollowing CIRIA’s usual practice, the research project was guided by a Steering Group which comprised:

ChairMartin Osborne Ewan Group (formerly Earth Tech Engineering)

MembersDarren Cook Hilton Hotels Group

David Calderbank Environment Agency

Alan Daw Thames Water(previously Sue Craddock)

Nigel Foster Bournemouth & West Hampshire Water

Meyrick Gough Southern Water(previously Magda Styles)

Gordon Hall Dwr Cymru

Adrian Jackson-Robbins Davis Langdon Consultancy (for DTI)(previously Lawrence Mbugwa)

Ian Newberry Three Valleys Water

Clare Ridgewell Essex & Suffolk Water(previously Sarah Bowerman)

Sue Roaf Oxford Brookes University

Martin Shouler Arup (formerly BRE)

Simon Walster Ofwat(previously Dean Bridge and Nicola Simpson)

Jon Wood South West Water

Alastair Wright Scottish Water Solutions (formerly East of Scotland Water)


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CIRIA’s research manager for this project was Paul Shaffer.

Project funders

The project was funded by DTI Partners in Innovation

Bournemouth and West Hampshire Water

Scottish Water

Environment Agency

Essex and Suffolk Water

Ofwat

Southern Water

South West Water

Veolia Water

Welsh Water

Published by CIRIA, Classic House, 174–180 Old Street, London EC1V 9BP, UK.All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, including photocopyingand recording, without the written permission of the copyright-holder, application for which should be addressed to the publisher. Suchwritten permission must also be obtained before any part of this publication is stored in a retrieval system of any nature.This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold and/ordistributed with the understanding that neither the author(s) nor the publisher is thereby engaged in rendering a specific legal or anyother professional service. While every effort has been made to ensure the accuracy and completeness of the publication, no warranty orfitness is provided or implied, and the author(s) and publisher shall have neither liability nor responsibility to any person or entity withrespect to any loss or damage arising from its use.


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