water efficiency guide

OFFICE AND PUBLIC BUILDINGS

WATER EFFICIENCY GUIDE:

October 2006

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS

The Department of the Environment and Heritage Content written by Robert Quinn of National Project Consultants Pty Ltd, Paul Bannister, Michael Munzinger and Chris Bloomfield of Exergy Australia Pty Ltd, and staff from the Department of the Environment and Heritage.

Graphic design by DesignInc, Melbourne.

This document has been printed by Focus Press, an Australian printing company with an Environmental Management System certified to ISO14001 standard and a member of the Greenhouse Challenge. The report was printed with vegetable-based inks.

ISBN 06425 52878

© Commonwealth of Australia 2006This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth, available from the Department of the Environment and Heritage. Requests and inquiries concerning reproduction and rights should be addressed to:

Assistant SecretaryEnvironment, Research and Information BranchDepartment of the Environment and HeritageGPO Box 787CANBERRA ACT 2601

DisclaimerThe views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment and Heritage.While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication.

For more information contact: [email protected]

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS

PROFORMA 19.05.06

All photos are the copyright of the Department of the Environment and Heritage (DEH) unless otherwise stated:

Front cover: water image (Stock XCHNG)P7: water management plan diagram (City West Water, Yarra Valley Water, South East Water)P9: waterless urinal and building (Energy Conserva-tion Systems Pty Ltd)P12: typical cooling towers (Lakeside Cooling Tow-ers)P13: cooling tower system schematic (Sydney Water Corporation)P14: cooling tower water use schematic (Sydney Water Corporation)P15: water feature, Water usage graph (Sydney Water Corporation)P19: Smart Approve Water Mark logo (WSAA)P20: Water Conservation Rating logo (WSAA)P21: toilet with cistern (Caroma Industries) flushom-eter type toilet (Toto USA Inc)P22: wall hung toilet (National Project Consultants) trough flushing urinals (Stoddart Industries)P23: waterless urinal cube (Desert Eco Systems Pty Ltd), cartridge (Allseal TM) cartridge less urinal trap (Allseal TM)P24: building (Colliers International)P26: outdoor mulch, Vegetation swale (Dominique Hes) P27: water tank installation (Dominique Hes)P28: DPI Ellenbank & Queenscliff (Department of Primary Industry, Victoria)P29: DPI Queenscliff & Ecocentre (Department of Primary Industry, Victoria)P34: Fig 8: management performance matrix (Na-tional Project Consultants)P35: Investa building (Sydney Water Corporation)P36: Investa people (Investa Properties Ltd)

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS �

contents

Contents

WATER EFFICIENCY GUIDE:

Executive SummaryForewords�.0 INTRODUCTIONWho should use this guideWhere water is usedHow to get started Role of the water supplier

2.0 TECHNICAL MEASURESWater auditing and meteringRectifying leakage (10-30% of water use)Cooling towers (30-40% of building consumption)Amenities (30-40% of building consumption) Kitchens and kitchenettesOutdoor and landscaping Retail areas Other water efficiency and conservation measures

3.0 MANAGEMENT AND BEHAVIOURAL MEASURESManagement frameworkKey measures

4.0 ASSESSING AND REPORTING PERFORMANCEConsumption performance Performance in water management practices

contents

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5.0 REFERENCES AND LINKS

APPENDIX: WATER INTENSITY BENCHMARKS FOR OFFICE AND PUBLIC BUILDINGS

CASE STUDIES40 Albert RoadIBM West Pennant HillsDPI Ellinbank, Queenscliff, Horsham Centres Investa Property Group

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS2

This publication has two parts. The first part is the Water Efficiency Guide: Office and Public Buildings. These guidelines provide an introduction to the technical and behavioural opportunities that exist in office and public buildings for reducing water consumption and increasing water reuse. Experience has shown that savings of between 30-40% are often achievable in these buildings. The guidelines will be useful for building managers, owners, tenants and maintenance staff.

The second part of the publication is the National water intensity benchmarks for office buildings and public buildings. These benchmarks have been developed from a national sample of building water consumption. For office buildings, the average water consumption was found to be 1.125 kL/m2 per year, with best practice being 0.5 kL/m2 per year. The benchmark set has been expressed using the same scoring methodology and 1-5 rating scale as the National Australian Built Environment Rating System (NABERS) and the Australian Building Greenhouse Rating (ABGR) scheme. Adjusted for climate, the new NABERS benchmarks, by major metropolitan centre, are:

Executive summary

For public buildings, a smaller sample meant a simpler bench marking approach. An average water consumption intensity of 3.34 kL/m2 per annum and a best practice target of 2 kL/m2 per annum have been identified based on the data.

This publication was developed in collaboration with the governments of Queensland, New South Wales, Victoria, South Australia, Western Australia and the Australian Capital Territory. We thank them for their support.

Table 1: NABERS benchmarks for office buildings (kL/m2/year).

Sydney Melbourne Canberra Adelaide Brisbane Perth

1 star 1.73 1.03 0.99 1.08 2.53 1.41

2 stars 1.39 0.86 0.83 0.9 1.99 1.14

2.5 stars 1.21 0.77 0.75 0.8 1.72 1.01

3 stars 1.04 0.69 0.67 0.71 1.44 0.88

3.5 stars 0.87 0.6 0.59 0.62 1.17 0.75

4 stars 0.7 0.53 0.51 0.53 0.9 0.61

4.5 stars 0.52 0.43 0.43 0.44 0.62 0.48

5 stars 0.35 0.35 0.35 0.35 0.35 0.35

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS 3

in our cities have concentrated on the use of water in the domestic sector. Water restrictions generally target households notably about the use of water in the garden. Programmes are also in place to assist large industrial users of water to become more efficient or to develop recycled water schemes that enable these industries to use recycled water rather than drinking water. The use of water in office and public buildings has often ‘slipped through the cracks’ and this is unfortunate given that with the expansion of Australia’s modern economy an increasing proportion of the workforce will be working in an office environment.

The publication of this guide is most welcome and very timely as it will provide the managers of office and public buildings with a guide on how to make their buildings more water efficient. Furthermore, the guide assists in evaluating the behavioural attitudes of people in the office environment as it relates to water use. The behavioural aspects are often equally as important as the physical hardware that might be installed in office buildings to ensure that they are more water efficient.

This document also strongly emphasises the importance of reporting and monitoring of progress which is critical to ensure that continuous improvement is achieved.

The water challenges confronting Australia dictate that all sectors must play their part in ensuring that our precious water resources are used in the most efficient manner. This manual provides the important role of ensuring that the office and public building sector plays its part in ensuring the efficient use of water in our cities.

ROSS YOUNGExecutive Director Water Services Association of Australia (WSAA)

Forewords

on our natural environment. However, less well known is the impact that society has and the water usage patterns of our facilities, particularly the high usage by offices and public buildings. New lessons for the built environment are now contained in this water efficiency guide from the Department of the Environment and Heritage.

This guide provides a practical introduction to water management plans containing information on a range of technical issues. Most importantly the guide makes the case for water consumption performance and provides benchmarking analysis for offices and public buildings.

This publication also aligns with the spirit of Facilities Management Action Agenda, where across innovation, education, regulatory and sustainability platforms, the Australian Government and industry are proactively working together for performance improvement.

I am delighted to be associated with this guide as it makes a real contribution on an important issue. Water efficiency is just one way we can work towards achieving a more productive and sustainable built environment.

STEPHEN BALLESTYChairmanFacility Management Association of Australia. (FMA Australia)

Australia’s cities face significant water challenges into the future due to the combination of rapidly growing populations and increasingly unreliable rainfall patterns due to climatic uncertainty.

Traditionally water conservation programs

Water is a precious resource, there is no substance on earth more crucial to life. Water scarcity is a major issue in Australia.

School children are taught the wonder and simplicity of the hydrologic or water cycle and its influence


Heating, ventilation and air conditioning (HVAC)

Amenities Leakage

Design Investigate site water collection and reuse options.Investigate waste water treatment options.Specify use of water wise landscaping.Negotiate water use, discharge and pricing options with utilities.

Specify minimum 4 star WELS rated fittings.Consider waterless urinals.Set a water intensity target for the building against benchmarks.

Design to include sub-metering of tenancies, plant and landscape uses.

Construction Ensure stormwater runoff is contained and sediment removed prior to leaving site.Consider setting goals for potable and non-potable water use on site.

Fitout and commissioning

Ensure that water saving and water treatment technologies are installed and commissioned as designed.

Ensure that WELS ratings are specified for water using fittings and appliances installed in any fitout.

Ensure sub-metering of tenancies occurs and is supported by appropriate leak detection and reporting signage.

Occupancy Ensure that responsibilities for water efficiency are clearly stated in leases and contracts for facilities management.Ensure that cooling towers are monitored and that risks of excessive water consumption (such as from blow-down) are managed proactively.

Provide information and training to building managers and users on efficiency measures and opportunities.Ensure cleaning staff are aware of water issues, including issues specific to waterless urinals.Cover amenities use in a water management plan.Be proactive about maintenance of valves etc.

Audit building water use periodically to identify base flows and unaccounted for water.Develop and implement a water management plan for the site (possibly as part of an EMS).Take a proactive approach to maintenance for leak prevention and remediation.Task cleaners and staff to report leaks promptly.

Refurbishment Investigate opportunities to upgrade cooling towers to improve efficiency.Consider installation of water storages and opportunities to install grey water ‘third pipe’ plumbing.Consider including a water intensity target in any new lease.

Benchmark building water performance before commencing refurbishment and set an intensity target for the refurbished building.Specify higher WELS rated appliances and fittings.Upgrade toilets and urinals to newest efficiencies.

Benchmark base flows before the refurbishment (including when building is empty). Identify leaks and correct while doing building works.Identify any overpressure problems that may require altering mains supply pressures.Improve sub-metering of tenancy spaces and specific uses.

Re-occupancy Ensure building management information and training takes advantage of new water efficiencies in the refurbished building.Ensure that responsibilities for water efficiency are clearly stated in leases and contracts for facilities management.

Provide information and training to building managers and users on efficiency measures and opportunities.Ensure cleaning staff are aware of water issues.Cover amenities use in a water management plan.Be proactive about maintenance of valves etc.

Audit building water use periodically to identify base flows and unaccounted for water.Develop and implement a water management plan for the site (possibly as part of an EMS).Take a proactive approach to maintenance for leak prevention and remediation.

End of life Ensure stormwater runoff is contained and sediment removed prior to leaving site.Consider setting goals for potable and non-potable water use on site during demolitions.Consider reuse of water storage, transport and treatment technologies from the old building if appropriate.

Water efficiency opportunities in office and public buildings


introduction

IntroductionWHO SHOULD USE THIS GUIDEThis guide is intended for use by anyone with a responsibility for, or an interest in, reducing water consumption. Ideally this would be anyone using, managing or maintaining a building. It is especially targeted at managers and officers tasked with reducing water consumption in their owned and leased facilities.

WHERE WATER IS USEDAudits of office buildings in Australia and overseas indicate that over 95% of water use in office buildings is accounted for by amenities, cooling towers and leakage. A typical end use breakdown is shown in the pie chart in Figure 1.

At this stage, no such data exists for public cultural buildings (such as art galleries, museums, libraries, archives); however, it would be reasonable to expect that cooling tower consumption would be of the order of 30%, leakage 20-25% and amenities possibly 40% or more given the relatively large number of public visitors. A similar end use pie chart will help users of this guide focus on the priority areas within their own buildings and should be prepared as part of a water audit.

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Figure 1: typical office water use.

Leakage 26% (taps, urinals, cisterns, piping, valves, pumps)Amenities 37% (toilets, kitchenettes, showers) Cooling towers 31% (air-conditioning, cooling towers)Other 2% (cleaning, car wash)Retail 3% (primarily food outlets) Irrigation 1% (landscaping, irrigation)

The commercial office building sector is a significant water end user. For example, office water use can account for 10% of capital city water consumption. A moderate sized building of 10 000m2 typically consumes over 20 000 litres per day or more than 7 million litres per year – enough to supply 40 average homes. The public building sector, although not as extensive as the office sector, does include a number of large and heavily used buildings that provide good opportunities for worthwhile water savings. Experience has shown that water savings of 30-40% are often achievable in both office and public buildings.

This guide identifies where water is used in typical offices and public buildings. It provides a range of practical and cost effective measures for reducing consumption. Technical and non-technical (management and behaviour related) measures are addressed – both play important roles in achieving savings and sustaining them. The guide also provides appropriate consumption performance measures and benchmark targets, as well as guidance on how to plan for and implement water efficiency improvement measures and assess the organisation’s performance in water management.

The guide is not intended to be a comprehensive handbook on water efficiency but taken together with the range of reference sources provided, most users will be able to achieve real water and cost savings.

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS�

introduction

Figure 2: water saving hierarchy.

a part of a broader, organisation-wide environmental management system (EMS), green office, facilities management or similar programme.

A suggested guide for the range of information to include in a Water Management Plan is outlined in Section 3.0 – Management and Behavioural Measures - further sources of information and background for developing your water management plan are outlined in Box 1. The range of assistance which can be accessed through your water supplier is outlined in Box 2.

A useful guide which outlines clear target areas for water savings is shown in Figure 2. They are arranged in priority order although obvious measures can of course be conducted in parallel. This hierarchy should be incorporated into the water management plan.

Two important first steps for a water management plan are to identify water end use categories and data log water meters.

A WMP need not be overly complicated and can be improved with feedback over time.

HOW TO GET STARTEDA solid foundation of effective preliminary investigation and planning provides the greatest chance of success in improving water efficiency. A usual first step is to draft a water management plan (WMP) to identify all the necessary actions and resources – these may include new or improved equipment, different processes, changes in behaviour and attitude, and of course, money and staff time.

Such a plan need not be overly complicated and can be enhanced and improved over time as feedback is received and data improves. A plan of three or four pages may suffice. The main thing is to start. Producing a formal WMP demonstrates management’s commitment to staff and is more likely to lead to cost effective and sustainable outcomes. Water management may be more effective and robust if it is

5. RecycleCan the water be recycled

for use elsewhere? eg process/grey

rainwaterwater

1. Rectify leaks

2. ReviewIs the process/activity really necessary?

Is it necessary to use water or is there a cost-effective alternative?

3. ReduceCould water be used more efficiently? Is there an alternative

process/activity which could be used?

4. Re-useCould the water be treated/filtered and

re-used within the process/activity?


introduction

Key resources for developing a water management planBOX 1

The guide begins with an overview of how to get started and gives detailed information about key steps in the process. It then provides a series of guides to the completion of each of the four action categories including subject headings and questions to be asked. These are followed by an action plan template and guidance on monitoring and review – this last step being important in both verifying that forecast outcomes are achieved and ensuring continuous improvement.

Every drop countsSydney Water Corporation’s demand management programme, Every Drop Counts recommends that seven key strategies be used in water efficiency planning and action:

1. Commitment – senior management (preferably the CEO)2. Responsibility – clearly define who will do what3. Baseline – information gathering, audit and analysis4. Efficiency opportunities – practical, efficient and cost effective measures5. Performance measurement

– intensity benchmarks, targets, monitoring, verification6. Conservation strategy – avoid, reduce, reuse and recycle opportunities7. Behavioural change – awareness, training, education, incentives.

These strategies and a range of other very useful materials are available at: http://www.sydneywater.com.au/SavingWater/InYourBusiness/FactSheets.cfm

Water conservation handbook for local governmentA handbook prepared by the South Australian Government to assist local government in managing and using water resources in their communities, available in hard copy and CD-ROM format and can be accessed on the web at:http://www.environment.sa.gov.au/sustainability/water_resources/index.html

Pathways to sustainabilityIn response to the Victorian Government’s Water Resource Strategy for the Greater Melbourne area, the three water retailers for the area developed Pathways to Sustainability, a water management plan information kit which proposes a WMP be divided into four action categories:

WATER CONSERVATION & EFFICIENCY

WASTE WATERMANAGEMENT

CULTURE & EDUCATION

OPERATIONAL EFFICIENCY

WATER MANAGEMENT

PLANACTION MONITOR/

REVIEW

Water saving action plansThe New South Wales Government requires high water users, state agencies and local councils to prepare water savings action plans. Information and resources are available on the web, including guidelines, guide notes and templates.http://www.deus.nsw.gov.au/waterandenergysavings/

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS�

introduction

BOX 2

In the face of dwindling water resources, most suppliers now have demand management strategies and demand management teams. An early step should be to contact the water retailer to see what assistance they can offer and take maximum advantage of any such free resources. Areas of assistance could include:

Technical support Most suppliers have project or technical officers who are experts in water supply and savings. They can help with equipment problems and compiling water management plans. They can also help explain tariffs and charges, and provide consumption data. Make good use of them.

AwarenessMany suppliers have guides, stickers, posters and checklists to assist awareness and education.

Flow monitoringWater audits routinely identify undetected leaks representing (10-50%) of consumption. Rectification of these usually provides good savings at remarkably low cost. The water supplier may be able to help with some time-of-use data logging (typically 5-minute intervals) to identify unnecessary base flows.

System pressureSystem pressure data can be requested from the supplier, they may even cover all or some of the cost of a pressure reducing valve if the mains pressure is found to be too high (500 kPa is adequate in most cases). However, expert advice may be needed, especially for high rise buildings as adequate pressures must be maintained at the upper levels. Excessive pressure is best evidenced by excessive basin spout flows for only small tap movements. Splashing

usually occurs, wetting both personnel and floors which can cause an Occupational Health and Safety issue.

Commonwealth employee workers’ compensation statistics in the five financial years from 1995 through to 2000 indicate that slips, trips and falls accounted for 18% of all claims, totalling over $48 million in direct costs to a slip, trip or fall. These are the second highest category of injury in terms of costs and number of incidents each year.

Billing and chargesAt least the following data needs to be collected in order to ensure comprehensive water consumption information is obtained:

billing period start and end dates

meter reading and consumption (kL) last bill

consumption history last 3-4 years

sewerage disposal (kL)

total water consumption cost ($)

sewerage disposal cost ($)

other charges (type and $) such as fixed fee per fixture

any factors used as a basis for charging (eg sewer use discharge factor)

unit charges ($/kL water, $/kL sewerage)

water meter number(s), size and fixed charges.

FundingFor most tenants and even building owners, capital is normally scarce. In appreciation of this, some water suppliers have funding facilitation arrangements such as leasing or loans with savings repayment options. Some initiatives may attract rebates or grants. Attractive paybacks can often be achieved with such support.

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Role of the water supplier

Metropolitan Water Utilities

SydneySydney Water Corporationwww.sydneywater.com.au

MelbourneCity West Waterwww.citywestwater.com.au

Yarra Valley Waterwww.yvw.com.au

HomeSouth East Water Limitedwww.southeastwater.com.au

BrisbaneBrisbane Water (Brisbane City Council) www.brisbane.qld.gov.au

AdelaideSA Waterwww.sawater.com.au

PerthWater Corporationwww.watercorporation.com.au

CanberraACTEW Corporationwww.actew.com.au

HobartHobart Waterwww.hobartwater.com.au

DarwinPower Waterwww.powerwater.com.au

case study


PROFORMA 19.05.06

COMPANY INTRODUCTION40 Albert Road sets a new benchmark in office refurbishment, achieving a 6 Star Green Star – Office Design certified rating, combining cutting edge sustainable design with a high end look and feel.

The initial approach to refurbish the building was driven by Peter Szental, who owns the Szencorp group of companies, The group specialises in water and energy solutions for commercial buildings, energy performance contracting, waste to energy technology, and property development.

The design combines original building features and fabric with an innovative program of alterations and additions to improve environmental performance and occupant amenity.

TECHNICAL MEASURESComprehensive water management system designed and built by the water conservation group from within Energy Conservation Systems. Water consumption is minimised at each end use point by using the latest in flow controlled showerheads and taps throughout.Dual flush design toilets: toilets are an award winning dual smartflush design using only 4.5/3 L per flush. Urinals are waterless.Grey water recycling: lightly polluted water gathered from hand basins and showers (greywater) is collected, treated and reused for toilet flushing.Rainwater harvesting: rainwater from the roof is collected to supplement the greywater supply for toilet flushing.Flow controlled taps.

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Minimal, water efficient landscaping.Electronic taps.

MANAGEMENT AND BEHAVIOURAL MEASURESIn order to maintain the 5 star ABGR rating, auditing and building tuning will be performed over 10 years.The manner in which the building is used by its occupants plays a significant role in influencing the volumes of water consumed in a building. Thus a building users’ guide will be available online and will provide tenants with all necessary instructions on how to properly use the building’s facilities.

ASSESSING AND REPORTING PERFORMANCEThe environmental performance of the building will be displayed online, linking the actual performance with information on how to improve it.

WATER SAVINGSCombined, these water efficiency measures have reduced mains water use to under 240 L/day for the whole building - saving over 82% compared to the original design.

Discharge to sewer will be reduced by 72%, thereby reducing sewage disposal charges

NABERS RATING: This equates to an (unofficial) 5-Star NABERS Office Water rating (at 0.1 kL/m2/year compared to the required standard of 0.35 kL/m2/year).

For more information: www.ourgreenoffice.com

REFERENCESThe Szencorp building: our green office. www.ourgreenoffice.com DEH (2006). ESD Design Guide for Australian

and Government Buildings, Edition 2.

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Building Type: Retrofit of existing office blockClimate: TemperateLocation: South Melbourne, VictoriaClient: SzencorpProject Manager: LascorpArchitects: SJB ArchitectsEngineers: Connell Mott Macdonald, Energy Conservation SystemsSize: �2�5m2 net lettable area.

40 Albert Road

Waterless urinal.

40 Albert Road.

technical measures

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS�0

WATER AUDITING AND METERING

Water auditsWater audits are a key part of water management. They are essential to gathering the facts and analysing them so as to provide management with options, costs, savings and financial returns. Audits form the basis for the sound decision making in the allocation of always scarce capital.

A variety of companies can deliver water audits. Ask your water supplier for their recommendations.

No standard exists for water audits. They are generally classified as basic and detailed. A basic level audit is always useful and often a good starting point to help scope complex buildings and systems that justify a detailed audit. The audit scope should include:

a breakdown of usage across the site and site activities, reconciled against total metered water consumptioninspection of equipment, devices and processes across the site as part of preparing a usage inventoryinvestigation of consumption by major equipment, devices and processesinvestigation of usage trends and patterns using monitoring as detailed below in this sectionpreparation of Key Performance Indicators (KPIs) of consumption (using baseline data) in relation to an appropriate business activity indicator (such as L/m2/year, or L/$

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of product made)comparison of monthly KPIs with industry benchmarks (where available) for baseline consumption, with consideration of site specific factors (such as climate) where appropriate development of a model or flow chart of consumption on the site utilising the equipment/device inventory and known consumption for the equipment (such as from suppliers, equipment manuals) and reconciling this with total site consumptionidentification and feasibility assessment of water savings measures (note, simple payback methods may not provide a true assessment, particularly for long-life measures; whole of life costs may need to be subject to discounted cash flow analysis to get the true picture).

It should be noted that in many cases water consumption data may be held by the building owner or the owner’s property manager. It will be necessary to get their permission to access this information from the water supplier.

MeteringInvestigation of the water consumption in office and public buildings has shown in many cases that there is inadequate or no metering (such as no submetering for a tenancy). Water meter data is important to a water management programme. For example, if the building is multi-

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Technical Measures2.0

tenanted without submetering, it will be necessary to work with the landlord to determine a satisfactory means of apportioning water consumption and costs following the implementation of water management initiatives.

Apportioning total building water use by the percentage of total net lettable area occupied by a tenant is one approach that can be used in the absence of tenancy submetering.Common metering-related issues which have been found in public sector buildings include:

no metering at all for a buildingno submetering for sections of buildings (such as base building, cooling tower or retail services)no submetering for individual tenancies meter oversized for the actual load.

The size of the water meter(s) should be reviewed as well as any consumption related factors that might be used to estimate sewerage discharges and costs. These may be set too high and a review based on time of use flow and sub metering data could well save thousands of dollars per year. For example, a sewerage charge of say $1.20/kL may be subject to a sewer use discharge factor of say 95% on the basis that only 5% of consumption does not go to sewer. If the building can be shown to have end uses that result in only 75% of metered consumption discharging to sewer then the effective sewer unit charge can be reduced from $1.14 to $0.90/kL.

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Rainwater capture 73 Miller St

At �3 Miller Street, North Sydney, rainwater captured from the roof of the Investa managed NSW Health building is being used for the irrigation of balcony and rooftop gardens instead of drinking water. The rainwater is fed into a holding tank in the basement and then pumped through a dedicated riser and drip fed to the gardens daily. (Sydney Water. The Conserver: Investa High benchmark for low water use. Issue 10, page 12, May 2006 Business Bulletin).

RECTIFYING LEAKAGE (10-30% OF WATER USE)Office and public building hydraulic systems and equipment are prone to leakage, especially if the local network pressures are high (500kPa is adequate for most buildings). Leakage losses of 10-30% are not uncommon. Many problems start off small and can be almost imperceptible (such as a slight leak from a toilet cistern) yet increase gradually over time.

Occupants can become desensitised to leaks and some are not detected and/or reported for 6-12 months if there is no routine maintenance inspection programme. Given that such leakage is on a 24x7 basis, even a modest leak of 2 L/minute accounts for 1000000 L over one year. In a large building even just 10 such small leaks can quickly aggregate into significant losses that are not obvious from the single meter consumption figure in a quarterly water bill.

Common sources of leakage in office and public buildings include cooling towers, taps (especially in high usage areas where tap washer wear is high), urinals, cistern flapper and filler ball valves, fire hose reels, underground pipes and control valves. Leakage is sometimes referred to as ‘unaccounted for water’ or ‘base flow’.

Water saving opportunitiesRectifying leaks quite often provides the best return on investment of all water saving measures. Such maintenance should be completed before any efficiency measures so that a true baseline of consumption can be established against which to check the savings from other measures. Possible actions include:

Install time of use data logger(s) set to 5 minute logging intervals on the main and any sub meters, check for out-of-hours flows. Best practice management has such loggers in

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technical measures

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS ��

place permanently with pre-set high flow levels above which alarms are raised. Progressive closure of isolation valves and analysis of logger data allows leaks to be quickly isolated and identified.Implement planned maintenance and/or replacement of problematic items regardless of condition (such as changing discharge flapper valves on cisterns every two years).Make leak reporting the responsibility of cleaners, maintenance contractors and security personnel (in addition to staff of course). Install stickers with hotline numbers to encourage visitors to report problems.Conduct 6-monthly inspections of grounds and storm water pits to observe damp areas or unexpected flows to drain.Regularly inspect and exercise hot water system pressure relief valves.

References1. Best Practice Guide for Clubs by

Sydney Water Corporation, Section 8 ‘Maintenance and Monitoring’.

2. Monitoring and Maintenance a Fact Sheet by Sydney Water Corporation.

3. Water Use and Conservation a US handbook by Amy Vickers, Sections 4.1 and 4.9.

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Install stickers with hotline numbers near taps to encourage leak reportage.

Signage at the Department of the Environment and Heritage, Canberra, to encourage leakage reporting among staff.

Signage at the Department of the Environment and Heritage, Canberra, to encourage water efficiency among staff.

technical measures


COOLING TOWERS (30-40% OF BUILDING CONSUMPTION)

Many commercial and public buildings, and in particular larger buildings, have cooling towers. Some 6500 such towers are registered in NSW alone. They can account for up to 30-40% of such a building’s water use. These towers will most likely be roof mounted (‘out of sight - out of mind’) so any water related problems cannot be easily identified. If towers are provided, they should be regularly monitored and thoroughly checked as part of a routine maintenance programme.

DescriptionCooling towers are used to cool condenser water (typically by 5.50C pumped to the roof from the building cooling plant (chillers or package units) after it has extracted heat from the building. They are essentially an open water reservoir or basin inside a vented enclosure with an extraction fan at the top. Warm condenser water is sprayed down onto internal fill material while air is drawn through it via vents at the bottom or sides of the tower. Water that is not lost to evaporation and drift then falls into the tower basin where it is treated before being returned to the cooling plant. Make up water needs to be supplied to compensate for water lost due to evaporation (an essential cooling process) and unnecessary losses. Figure 3 shows photos of a large timber-framed tower on the left and a smaller package-type unit above. Figure 4 on the next page provides a schematic of the key components of a cooling tower.

Figure 3: typical cooling towers.

technical measures

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS �3

Figure 4: cooling tower system schematic.

technical measures


Water use in cooling towersWater is lost from cooling tower systems for a range of reasons. The common areas of loss are shown in Figure 5 and discussed below.

Figure 6 shows the typical breakdown of evaporation, bleed/blow-down, drift and splash (these terms are explained below) in a well-designed tower, which together can account for 30-40% of total water consumption in buildings with cooling towers. This percentage can be higher if the system has leakage, water treatment or overfilling problems. These losses are compensated for by make up water (usually from the potable water supply) which is added to the basin and regulated via a float valve.

The percentages shown are of the circulating cooling water. For a 1050 kilowatt tower this could be 25L/minute. The bleed shown is for cycles of concentration ratio of 2. Improving this ratio from 2 to 12 will save 45% of water used (10-11L/minute).

Figure 6: water consumption for a well maintained cooling tower.

Figure 5: cooling tower water use schematic.

Evaporation 88% Bleed 5% Drift/Splash 7%

case study

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS �5

PROFORMA 19.05.06

INTRODUCTIONThe IBM West Pennant Hills Data Centre in NSW has taken to water conservation with gusto, cutting water use by more than 60% in just two years. When IBM joined Sydney Water’s Every Drop Counts Business Programme in May 2003, its West Pennant Hills site was one of its highest water users. Now, the site can proudly boast water savings of 160 kilolitres (kL) a day.

TECHNICAL MEASURESA water use monitoring programme is in place which enables daily monitoring of water consumption in a number of high water use areas across the site. This monitoring is used to track usage and identify any anomalies, such as those caused by leaks. Annual progress in water conservation is reviewed weekly by operational staff, presented to senior management periodically and reported annually in the IBM Environment & Well Being Progress Report for Australia and New Zealand on a total site and kilolitres of water used per square meter of net leased area (kL/m2/year) basis.

One of the water conservation initiatives implemented by IBM Australia has been repairs made to the ornamental ponds system at the site. “The leak in the ponds was discovered by visual observation and we attribute this discovery to the heightened staff awareness we have developed through our EDC involvement,” IBM’s Environmental Manager, Mr Michael Chanell said. Since then further new leaks in the pond system have been identified through the monitoring programme.

Another water conservation initiative implemented by IBM Australia to achieve the 160 kL/day water saving has been improvements to the urinals. “Our facility management contractors, Johnson Controls, replaced the timed flushing systems with sensor-activated devices,” Mr. Chanell said. “This relatively straightforward step saved us 42 million litres of water over a year.” The new devices delivered a remarkable $82 500 annual saving at a capital cost of $27 800 – a simple payback of just four months.

Further improvements such as extending the time delay before flushing are also saving water without compromising hygiene standards.

Prior to joining the EDC Programme, IBM had introduced a project to plant more native species. This initiative resulted in significant water savings, with no irrigation now being required over most of the

Building Type: Climate: Location: Client: Participating Organisations: Size:

IBM West Pennant Hills

landscaped area. When the property was developed in the early to middle 80s more than 40 000 trees were planted across the 26 hectare site to complete the integration of the office building and data centre with the natural environment.

ASSESSING AND REPORTING PERFORMANCEWater use is a Key Performance Indicator at IBM, which reduced its water use at its West Pennant Hills site from 3.7 kL per square metre of net leased area in 2000, down to 1.2 kL per square metre in 2004, largely as a result of a water use monitoring program and water conservation initiatives.

REFERENCESSydney Water (2005). High end data centre

delivers low end water consumption. The conserver: Every drop counts business bulletin. 8 August 2005.

www.ibm.com/ibm/au/environment

Figure 7: water usage at IBM’s West Pennant Hills Data Centre.

Above: one of the two water features at IBM’s Pennant Hills Data Centre where water leaks were identified and fixed.

Retrofit of existing office building with data centreTemperateWest Pennant Hills, SydneyIBMIBM Australia, Johnson Controls, Sydney Water2� ha site, 34 0�0 m2 net leased area

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WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS��

COOLING TOWER EFFICIENCY AND IMPROVEMENT MEASURES

The typical problem areas and suitable response measures are discussed below.

Overflow - occurs when the level of water within a cooling tower basin rises above a predetermined design level. Normally this water flows down an overflow pipe to the sewer. In some cases it can account for up to 40% of daily make up water. This wastage is often due to operational problems or inadequate maintenance such as water supply ball valve repair or adjustment, overflow pipe repositioning or leak repair, condenser water pipes not positioned below tower spray head so as to eliminate backflow or water imbalance between interconnected towers.

Leaks - leaks can occur in tower basins or casings, flexible connections, pump gland seals and control valves. They are usually evident from ponding around the tower.

Evaporation - the amount of water consumed through evaporation is dictated by the temperature difference between the condenser water inlet and outlet of the cooling tower. Evaporation is an essential and unavoidable part of the water cooling process in cooling towers.

Bleed - to prevent the build up of dissolved and suspended solids (both organic and mineral) in the water left behind after evaporation, some water must bleed off from the basin to allow dilution by fresh water. The bleed or blow-down process is normally automatic and controlled via a sensor that measures Total Dissolved Solids (TDS) concentrations in the water as indicated by water conductivity. When the conductivity reaches a

predetermined setting, the bleed valve opens and so allows water to flow from the tower’s basin to the sewer. Savings measures include:

Conduct monthly cleaning of sensors plus at least a 6-monthly calibration to make sure it is not causing unnecessary bleedFitting automatic bleed lockout to prevent bleed off when the system is being injected with biocide.Maximising the cycles of concentration used (the ratio of the concentration of dissolved solids in the condenser water to those in the make up water), a ratio that is reflected by the water conductivity as measured by a sensor. Increasing this ratio from 3 to 9 can reduce bleed water volumes by 25% - ratios of less than 3 are indicative of very high bleed water losses and hence costs in water, sewer and chemicals.Bleeding off water may well present a reuse opportunity for landscape irrigation. However, quantities may be relatively small and treatment may be necessary before reuse (OH&S issues) so these factors should be carefully considered in any feasibility analysis.

Drift - is the water lost from the cooling tower as liquid droplets entrained in the exhaust air, excluding condensation. Current standards limit drift to 0.002% of the circulated flow rate. Measures include the fitting of drift eliminators or arrestors. Reducing drift also results in chemical cost savings.

Splash - is due to water being accidentally lost from a cooling tower due to the splashing action of falling water within the tower or the effect of a strong wind blowing through a tower exposed to the elements. This is usually due to poor design. The fitting

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of anti-splash louvres or splash mats, or the installation of wind breaks will reduce splash losses.

Plant operation loads and times - reducing the amount of central plant in operation and/or the time for which it operates also reduces cooling tower water losses (and saves energy). The Building Management System settings should be checked to ensure that plant is not starting too early, running too late or operating unnecessarily on weekends. The controls and plant configuration should also be reviewed to make sure that only the minimum needed is in operation at any time. After hours tenant requests for service may be bringing on all tower pumps and fans when only one of a multi-tower bank may be needed. A cooling tower bypass valve can also reduce tower losses for instances of low heat load (such as mild weather, partial building occupancy). Fitting variable speed drives to cooling tower fans also helps, they allow system operation to better reflect actual load requirements and so reduce water consumption. Associated energy savings may far exceed the water cost savings and so free up funds for investment in further water efficiency measures.

Plant maintenance - building managers and their maintenance contractors should consider a range of strategies to achieve optimum cooling tower performance:

Adopt a risk management/performance based maintenance regime rather than routine periodic (such as every 6 months) programme, as such periodic programmes can lead to unnecessary chemical and water use. However, some authorities do not permit performance-based regimes.

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technical measures


Targets for water and chemical use and cycles of concentration should be agreed, set and closely monitored. Include a system diagnostic check list as part of any routine monthly checks and other contractor service visits. If side stream filters are fitted, use bag or cartridge filters in the ‘back wash’ process, or at least capture bleed-off water and use it for back washing. An effective plant scale, corrosion and bio-fouling protection plan will ensure chillers operate at maximum efficiency and so reduce cooling tower loads and hence water losses. Fan belt tightness should be regularly checked. If belts are loose then operating times may be extended to compensate for loss of tower performance which will result in greater tower water loss.Consider non-chemical water treatment options such as ozone and ultraviolet that usually offer superior performance and reduced maintenance.

Water treatment - cooling towers represent a very complex and dynamic water system. The water must be treated to address constantly changing biological, scale, erosion, corrosion and sludge issues. A complex mix of corrosion inhibitors, antiscalants, antifoulants, dispersants, surfactants, biocides and pH control chemicals is needed. These need to be carefully managed by a treatment expert, as major health issues and equipment damage can occur in just a couple of days. There is no ‘set and forget’ option for water treatment. Biological treatment eliminates organisms such as Legionella bacteria (a major health risk) as well as viruses, fungi, slime and algae which in such an ideal moist and

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warm environment can build up into a biofilm that fouls heat exchangers and attacks components. These biological treatments also indirectly reduce scale build up as mineral micro-crystals (calcium and magnesium commonly) adhere especially well to biofilm.

Other treatments (such as acidic compounds) directly reduce the build up in mineral concentrations (commonly calcium chloride) in the cooling plant. Such minerals are introduced by the make up water but are left behind by water evaporating from the system. Left unchecked the mineral concentrations would build up to a point where they are so concentrated they would begin to settle out of the condenser water to form scale. Whilst adding make up water can reduce the concentrations, chemicals can allow the concentration to increase before scaling occurs. This saves bleed water and the loss of other expensive chemicals.

Chemicals are also added to inhibit corrosion. Typically such chemicals are injected by dosing equipment. Hexavalent chromium-based (‘chrome’) compounds are among the most efficient and cheapest corrosion inhibitors available. However, hexavalent chromium is a suspected carcinogen, and is highly toxic. However, there are now other non-chemical options at least for biological treatment or disinfection, such as ozone or ultraviolet based treatment systems.

Ozone - is a high energy form of oxygen and the most efficient broad spectrum microbial control agent available. Correctly applied (some installations and operating environments are unsuitable), it destroys all bacteria, viruses and cysts, including Legionella. The ozone is produced electronically in an ozone

Parliament House in Canberra has installed a heat exchanger to capture waste heat from a large data centre and use it to heat swimming pool water, reducing energy consumption, saving money and also saving water through a reduced cooling tower load and water use.

Parliament HouseCanberra

technical measures

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS��

generator under vacuum conditions. It is drawn into the cooling water, producing a powerful biocidal effect throughout the cooling tower and the cooling system. Acting as a biocide throughout the cooling system, it destroys bacteria, algae and viruses, both in the water and attached to the pipe work and cooling tower.

Ozone treatment reduces the amount of other biocides needed or can even eliminate them. Its effectiveness reduces the quantity of dissolved solids and so reduces the amount of bleed needed. In reducing biofilm, equipment efficiency is improved so tower operating times are reduced, thereby reducing losses due to leaks, splash and drift. Case studies indicate that bleed can be reduced by 90%, cycles of concentration ratios can increase from 5-10 to 30-40 and bacterial counts are reduced by three orders of magnitude. There can be some corrosion issues, but on balance, no worse than for the chemicals displaced.

Ultraviolet (UV) - treatment systems pass tower basin water through a UV unit which destroys pathogenic bacteria and viruses. It is a non-corrosive process, so no chemicals need be stored on site. Also, no biocides are present to be carried off-site in tower drift and there are no chemicals to adversely impact the system water pH or its composition. The capital costs and the running costs are low, and the equipment usually suits retrofit situations.

For similar reasons to ozone treatment, UV water treatment systems save water. In addition, chemical and energy costs are lowered and waste water quality improved (for chemical treatment systems some authorities may require treatment of bleed water

Heat recovery - it may be feasible for heat from condenser water flows to be recovered via heat exchangers and used elsewhere in the building (such as pre-heating the supply to hot water boilers). Energy cost savings can then be made available for funding water saving measures. Any heat extracted by the heat exchanger will reduce the tower cooling load and

Whole of life cycle costs of alternatives to chemical dosing should be investigated.

thereby directly reduce tower water consumption.

Consumption monitoring - fitting sub meters to tower makeup water supply and the blow down lines, with regular monitoring via the Building Management System (BMS) or a specialist water monitoring system, is an effective way of keeping a focus on performance and getting an early warning of problems. Failing this, meter readings should be recorded weekly. Either way, the consumption should be reviewed weekly, or performance assessed based on the floor area (m2) cooled, the operating hours and the climatic conditions. A history of data will allow future anomalies to be quickly identified and acted on. Towers can also be benchmarked to assess relative performance. Fitting a sub meter to the bleed off or blow down system is also useful for two other reasons – it allows closer monitoring and control of expensive chemical dosing and provides data that may support a claim to reduce the site sewerage use discharge factor and so save on sewerage charges.

References1. Best Practice Guidelines for Cooling

Towers in Commercial Buildings-a comprehensive guide which includes a checklist that should be used as part of the implementation of the Water Management Plan.

(http://www.sydneywater.com.au/Publications/_download.cfm?DownloadFile=FactSheets/savingWaterBestPractiveGuidelinesCoolingTowers.pdf2. Water Use and Conservation a US

handbook by Amy Vickers, Section 4.7

prior to discharge). However, the UV elements require cleaning to maintain effectiveness (some newer units are self-cleaning). They must also be correctly sized to suit the water volume. Therefore, the whole of life cycle costs and benefits of such alternatives to chemical dosing should be investigated.

Tower water filtration - the cooling tower sprays pick up air pollutants and deposit them into the cooling tower water system. The water supply itself may also carry sediment. Among other operational problems, this increases both the need for chemical treatment and the need for blow down. The fitting of filters can reduce this contamination by 2-10% with 10-20% savings in chemicals and blow down water possible, depending on ambient air pollution levels.

Tower air filtration - some towers can be exposed to larger air borne contamination (such as leaves, insects, paper) which are drawn into the tower water, especially if wave type air inlets are fitted. This material also leads to increased treatment and blow down volumes. The fitting of air intake filters can often be justified purely for operation and maintenance reasons, with water savings being a bonus - they should be considered as part of any water efficiency audit. Care must be taken to avoid unneccesary pressure drops or energy use will have to increase to maintain effectiveness.

technical measures


Water efficiency labelling and standards (WELS) schemeWater efficiency labelling

and standards (WELS)

www.waterrating.gov.au

Water efficient appliances are one way of conserving water while saving money.

The WELS scheme introduces mandatory water efficiency labels for all showerheads, washing machines, toilets, dishwashers, urinals and some types of taps, as well as minimum water efficiency standards for toilets and voluntary labels on flow control devices.

Labels will begin to appear on fixtures and appliances from July 2005 and the scheme will extend to further products where appropriate.

By choosing more efficient appliances, by 2021 the community stands to save more than $600 million through reduced water and energy bills.

By 2021, domestic water use is projected to be reduced by 87 200 megalitres per year (or five per cent), totalling a saving of 610 000 megalitres – more water than in Sydney Harbour.

The scheme will also reduce greenhouse gas emissions. By 2021, the amount of energy saved each year will equal taking around 150 000 cars of Australia’s roads.

Smart Approved WaterMark

Smart Approved WaterMark is Australia’s water saving labelling programme for products, services and organisations which are helping reduce outdoor water use.

It is a voluntary and not-for-profit scheme that allows consumers to make an informed choice towards saving water.

The Smart Approved WaterMark label can be applied to:

outdoor water using/saving products

outdoor water related services

outdoor water related organisations

Details of all products, services and organisations are to be submitted to the independent expert panel for assessment.

The scheme is managed by Australia’s peak bodies of the urban water industry and leading authorities on outdoor water use.

As well as looking for the Smart Approved WaterMark label, if significant outdoor water use occurs at sites you manage, you may want to consider applying for the award of the label to recognise your efforts in water conservation.

www.wsaa.asn.au/smartwatermark/smartabout.htm



Labels will begin to appear on fixtures and appliances from July 2005 and the scheme will extend to further products where appropriate. By choosing more efficient appliances, by 2021 the community stands to save more than $600 million through reduced water and energy bills.

By 2021, domestic water use is projected to be reduced by 87 200 megalitres per year (or 5%), totalling a saving of 610 000 megalitres – more water than in Sydney Harbour.



Smart approved watermark

Water efficiency labelling and standards (WELS)




Labels will begin to appear on fixtures and appliances from July 2005 and the scheme will extend to further products where appropriate.

By choosing more efficient appliances, by 2021 the community stands to save more than $600 million through reduced water and energy bills.

By 2021, domestic water use is projected to be reduced by 87 200 megalitres per year (or five per cent), totalling a saving of 610 000 megalitres – more water than in Sydney Harbour.


Smart Approved WaterMark

Smart Approved WaterMark is Australia’s water saving labelling programme for products, services and organisations which are helping reduce outdoor water use.

It is a voluntary and not-for-profit scheme that allows consumers to make an informed choice towards saving water.


outdoor water using/saving products

outdoor water related services

outdoor water related organisations




www.wsaa.asn.au/smartwatermark/smartabout.htmSmart Approved WaterMark is Australia’s water saving labelling programme for products, services and organisations which are helping reduce outdoor water use. It is a voluntary and not-for-profit scheme that allows consumers to make an informed choice towards saving water.


• outdoor water using/saving products• outdoor water related services• outdoor water related organisations.




www.wsaa.asn.au/smartwatermark/smartabout.htm

technical measures


AMENITIES (30-40% OF BUILDING CONSUMPTION)

Background and standardsUrinals, toilets and taps are all common sources of water waste and maintenance costs in office and public buildings. Some buildings also provide shower facilities although this is not common and usage by occupants may be low.

The Australian Government, in collaboration with state and territory governments, has introduced the Water Efficiency Labelling and Standards (WELS) scheme that has mandatory national water efficiency labelling and minimum performance standards for domestic water-using devices. The water-using products covered by WELS initially include: showerheads, washing machines, dishwashers, toilets, taps, flow regulators and urinals.

At present the Water Services Association of Australia (WSAA) coordinates an independent product rating system (A to AAAAA). It predates WELS and is to be phased out by 1 July 2006. Both schemes work much like the 5-star energy rating used for household appliances and under either scheme a changeover to higher star-rated equipment can often be justified. For new construction and major refurbishments higher rated equipment is nearly always justified and may well be mandated by local authorities as a development consent condition.

Water closets Water closets (WCs) or toilets can use anywhere from 11 litres per flush for the older style single flush models to an average of 4-5 litres for the now common ‘6/3’ dual flush toilet or even less for the just released 4.5/3 litre, dual flush model. A relatively

high utilisation rate of 50 flushes per day will provide total water savings of about 170 litres/day (more than 60000 litres per year or cost savings of $150 per year in Sydney) for the replacement of a 11 litre single flush with a 4.5/3 litre dual flush unit.

Water savings and costs of implementation will vary greatly depending on the level of use, the specific water savings measures, the type of pan installed, such factors as the plumbing arrangements and the architectural finishes. It is not unusual for it to be uneconomic to replace older style WCs except as part of a major building or floor upgrade.

These are three basic types of WC:

Gravity tank - comprises a bowl or pan with a tank connected by a flush pipe. The tank is integrated with the pan on modern WCs, older styles can have the tank 2m above the pan. Gravity tank toilets are relatively inexpensive and are most commonly found in residential and lower grade commercial and public buildings. They rely on the volume of water in the tank to flush waste and usually require water pressure of no more than 70-100 kPa to operate properly. Low pressure just means longer tank refill periods, although this increase in cycle time can be an issue when utilisation is high as for museum toilet facilities.

Older style gravity tank toilets use up to 11 litres of water for every flush. The currently common dual flush toilet suites provide 6 litres for a full flush and 3 litres for a half flush (6/3) and achieves a 3A water-efficiency rating. However, products just released onto the market have a 4.5/3 L dual flush cistern reducing water use to 4.5 litres for a full flush and so achieve a 4A water-efficiency rating.

Water Services Association of Australia (WSAA). http://www.wsaa.asn.au/

Water Efficiency Labelling and Standards (WELS) Scheme.


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WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS 2�

Flush valve operated - this type of toilet is considered to be more heavy duty than the gravity tank type. It is found in quality office buildings, high use public areas and hospitals. Instead of a storage tank, this toilet uses a ‘flushometer’ valve directly connected to the water supply plumbing. This valve controls the quantity of water released over time by each flush. It is very important that there is a proper match between the valve and the bowl or pan. Unlike tank-type toilets, flushometer valve toilets must accommodate different water pressures at different points in a building. Flushometer toilets usually require a minimum water pressure of 175-275 kPa to operate well. They are very susceptible to clogging due to unclean water and rely on an adjustable valve for flush timing. Given that there is no tank to fill, there is no cycle time limit so they are ideal for heavy use public facilities.

Pressurised tank - a less common and relatively new design uses water line pressure to achieve a higher flush velocity. Water is not stored inside a cistern, but in a vessel that compresses a pocket of air and releases pressurised water into the bowl and out the trapway. They require a minimum water pressure of 175 kPa to operate well and they may not be suitable for a retrofit installation depending on the nature of the existing plumbing. They give an excellent and consistent cleaning action, are low maintenance and are very water efficient. However, like the gravity tank type, they have a finite cycle time which may make them unsuitable for busy public facilities.

Dual flush toilet with integrated cistern.

Flushometer type toilet.

Rainwater collection system, 126 Phillip St, Sydney

In 2003, Investa acquired �2� Phillip Street, Sydney a landmark Foster & Partners designed building. In 2005 they focused on enhancing the building’s sustainability initiatives during the final stages of construction. A rainwater collection system has been installed to collect most rainwater discharged from the building. Water from the �5 000 litre tank will be used for irrigation of the gardens, and for toilet functions on the ground floor.(Investa 2005 Sustainability Report, p 23).

technical measures


Water closet efficiency measures

Gravity tank system:

It is not always feasible to replace old single flush WCs completely but there is a range of improvement options available:

Cistern replacement - some pans with 11 L cisterns can accept a simple replacement 6/3 cistern and this is usually very cost effective (payback of 2-3 years or less). These work well in low flush (3 L) mode where the toilet is frequently used as a urinal, such as in busy public areas. However, some bowls will not clean solid waste properly with the reduced 6 L flushing volume. These types require a complete toilet suite changeover. Costs are very much site dependent, but can be as high as $1500 or even more if building and architectural works are also needed. Savings of $150 - $200 or less per year can mean infeasible paybacks of over 10 years. In these cases, changeovers should occur as part of refurbishment programme.

Flapper valve changeover - many single flush cisterns can be retrofitted with early closure flapper valves (valves that control the flow of water to the bowl) that reduce the flush volume. However, some pans will not clean solids properly with the reduced flushing volume.

Flapper valve maintenance - flapper valves become worn or their seats corroded causing water to continually leak into the pan. These leaks can be very hard to detect; however, a few drops of food colouring added to the cistern makes problems more evident. These valves are problematic and should be replaced every 2 years as part of programmed maintenance.

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Conventional wall hung and trough flushing urinals.

Cistern displacement devices - nearly all single flush 11 L cisterns can be fitted with water displacement devices or water dams to keep 2-4 litres out of the flushing cycle – paybacks of 1 year or less can be expected. Again, some pans will not clean solids properly with the reduced flushing volume.

Float valves - incorrectly set or water logged ball float valves on the inlet water supply cause cisterns to continually overflow. This flow can be very hard to detect, especially if only of the order of ½ litre per minute; however even this small flow rate will waste more than 250 000 litres per year and cost $500 (in the Sydney area).

Flush mechanism - worn or damaged flush mechanisms (such as bent control wire) can also cause water to continually leak into the pan.

Overflow pipe setting - setting the overflow pipe too high causes excess flushing volume.

Inspection regime - conduct a six- monthly check regime and include leak reporting in cleaners’ scope of work. Stickers in prominent positions can urge people to do the right thing and report leaks to a help desk number.

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Flush valve system These systems do not offer as many opportunities as gravity tank systems as they are simpler and more reliable. This is why they are often installed in high-use public buildings such as museums, galleries and hospitals. Measures include:

Timing - check timer adjustment setting (if fitted) to eliminate overly long flushing or retrofit lower flow diaphragm (if the pan is suitable). A qualified plumber, experienced in commercial office work, will know how best to adjust the timing to suit the available pressure and bowl design – around 10 seconds would be typical.

Diaphragm replacement - replace worn diaphragm, clean debris from by-pass orifice or bleed air from the line to stop slow leaks or failure to shut off.

Water seals - rectify relief valve seating and/or control lever water seal to stop slow leaks.

Inspection regime - conduct a six- monthly check regime and include leak reporting in the cleaners’ scope of work. Provide leak reporting stickers.

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technical measures


Savings depend on the level of usage and property maintenance practices. The following provides a ‘shopping list’ of possibilities which should be costed as part of a water audit or whole of life design check for new construction and refurbishment works.

Urinals water efficiency opportunitiesA range of often simple and cost effective measures are available for what can be very wasteful installations:

Changeover to waterless - high priority should be given to determining the feasibility of installing waterless urinals (both wall hung and trough type) as part of new and major refurbishment works – such measures are unlikely to be feasible as stand alone projects. These units have been successfully used in Europe and the USA for over 10 years with annual water savings of 170 000 L per urinal in some US schools. An increasing number of local users report good results; however, some odour and operating cost issues are being reported. If cleaning staff are not given proper instruction then the special trap fluid can be quickly rendered ineffective. Maintenance staff need instruction as to when cartridges or the trap solution needs to be changed – early replacement could lead to replacement costs exceeding the water and sewer cost savings. For some urinals a replacement mechanical cartridge is available that uses a synthetic bladder (developed by NASA for use in men’s space suits) that takes the place of a trap. These are maintenance free.

Conversion to waterless – some manufacturers have developed

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Urinals Urinals can be a multi-user trough or individual wall hung pods. Flushing mechanisms can be a manually operated cistern (concealed push button or exposed overhead chain-pull), lever operated flushometer or a movement sensor controlled solenoid valve. Consumption depends on usage levels, equipment type and settings – it can vary from 50 000 to 100000 litres per year (30-70 flushes of 4 litres each per day). However, there are still some cyclic ‘fill and dump’ units installed that operate on a 24x7 basis and these can waste over 500 000 litres per year.

Waterless urinalsBoth wall hung and trough type urinals are now available in a waterless design. Many incorporate a cartridge that must be replaced after a certain number of uses. However, some equipment now on the market has the advantage of not requiring a trap cartridge thereby further reducing operating costs. These use a special liquid filled trap incorporated into the urinal rather than a replaceable cartridge. The trap lets urine go to the sewer but acts as a seal to block odours. The biodegradable odour-blocking fluid is poured into the waste trap and floats on the surface of the urine to create a perfect seal, blocking any urine odours. The denser urine flows through the liquid and out of the urinal waste pipe to the sewer. The blocking fluid remains effective for approximately 5000-7000 visits.

Neither type of urinal requires water hence there are no cisterns or flushing mechanisms to fail or maintain. For flushing urinals the cost of efficiency measures depends very much on the type of equipment and the nature of the plumbing installation.

Waterless urinal.

Cartridge-less waterless urinal trap. Cartridge-less Waterless Urinal Trap

Cartridge.

Waterless urinal cubes.

technical measures


TapsExcessive flows and/or leaks from taps in toilet areas, kitchenettes and cleaners’ sinks can be a significant source of water waste. Showers can be another significant source of water waste although they are not common in most offices and public buildings. However, a single dripping tap can waste more than 24 000 litres per year. Unregulated flows can reach 15-20 L/minute (with splashing that wets users and floors causing an occupational health and safety hazard) when 6 L/minute or even less is enough for hand washing. Reducing flows from hot water taps has the added benefit of saving energy. Such savings typically exceed the water cost savings by 2 or 3 to one.

Tap water efficiency measures Some very simple and inexpensive retrofit measures are available for existing devices that save water as

materials that allow any flushing type urinal to be converted to a waterless operation. Small dissolvable cubes which contain surfactants and microbes that together keep the flush pipe clean are put in the unit and the water is turned off.Pipes from urinals have a build up of uric scale, a compound of urine that is practically insoluble. It is the cause of most of the unpleasant ammonia/urine smells and blockages in male toilets. The usual response is to flush water down the system which just makes it worse. The cubes remove existing scale and prevent further build up. The surfactants and the microbes are an all-natural product and are 100% bio-degradable. Once the cubes are installed they ultimately eliminate the need for washing the urinal down with other harsh chemicals like bleach or acid. The Pier Hotel in Port Lincoln in South Australia recently saved 80 000 litres of water in three months by using the cubes, which were nominated for an annual SA water industry alliance award.

Eliminate cyclical flushing - cyclical flushing units are the most water inefficient type of urinal and should be replaced immediately. Manual pull chain or movement sensor controlled solenoid valve mechanisms are suitable controls. Savings of 500 000 litres and $1000 per year are possible with a payback of less than 6 months.

Flush volume reduction - reduce cistern or flushometer volumes to the minimum by adjustment or replacement of valves. As little as 1-2 litres/flush may well be adequate versus the 3-6 litres commonly used.

Cistern flapper valve - routine replacement of cistern flapper valves every 2 years.

Movement sensors – sensor controlled flushing is marketed as best practice in water saving;

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however, as with other so called smart technology, in practice such systems can in reality use more water than the ones they replace. Areas to address include:

a) adjusting moving or adding movement sensors so as to avoid spurious activation by passing trafficb) ensuring each urinal has its own sensor, which only activates water supply to that urinalc) reprogramming sensor controls to only flush after multiple uses or increase time delay to say 15 minutesd) ensuring battery powered sensors and mechanisms have mains power charging option fittede) minimising flush time, such as to five seconds.

Routine inspections - conduct a six-monthly check regime and include leak reporting in the cleaners’ scope of work. Support this with leak reporting stickers or signs visible to users.

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Colliers International - water savings

Colliers International’s Adelaide office at �0 Pulteney Street is leading the field in the implementation of water saving initiatives. The installation of waterless urinal cubes throughout the �� floors complex has seen a reduction in water consumption in the building over the past �2 months of about 4 million litres. The initiative cost $2400 and delivered water cost-savings and reduced plumbing costs of $�200. Colliers International continues to implement this and other initiatives across a number of portfolios around the country. (Colliers International. Property Management Knowledge Report, March 2005).

technical measures


well as energy whilst improving user amenity and safety. Savings of 20-30% are common with paybacks of less than 2 years. New water efficient, WELS compliant tapware is also now available for use in new construction and major refurbishments. A range of measures is summarised below:

Fit new water efficient tapware- typical taps discharge 15 to 20 L minute but new low-flow and aerating models may use as little as 2 L minute, depending on the intended application.

Fit low flow aerators to basin spouts which may reduce the flow to less than a third (6 L/minute or less). This is an inexpensive option but devices are subject to clogging and tampering.

Throttling back under-basin control valves (where fitted) to 6 L/minute or less and removing handles to avoid tampering are cost effective measures. Over throttling can lead to jumper valve noise and/or tap seat wear problems. In higher use areas it may be preferable to fit in-tap flow regulators and long life jumper valves to achieve a more robust and tamper proof solution.

Fit movement-sensor operated basin spouts that automatically turn on but only when the hands are placed under the spout. Whilst this is arguably the most hygienic and efficient solution to basin water control, these systems are somewhat expensive and introduce another level of maintenance complexity. They may only prove feasible in very high usage areas and in buildings subject to best practice maintenance.

Fit lever or button operated timer taps that allow water to flow for 10-15 seconds after operation. Some have built-in, adjustable flow regulators. Whilst not as hygienic or efficient as movement-sensor

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controlled spouts, they are not so complex and are less costly.

For showers, fit low flow heads or in-tap regulators to reduce flows from 15-25 L/minute to less than 10 L/minute. Care needs to be taken in choosing shower heads so as to achieve an acceptable spray pattern. The back pressure produced can exacerbate leaks from worn tap spindles (such leaks are often hidden as they occur behind the wall tiles). Taps should be refurbished at the same time as fitting the shower head or consider fitting in-tap flow regulators instead provided an acceptable spray pattern can be achieved with the existing shower rose.

Fit long life tap washers (usually with a rubber O-ring and mechanical protection against over tightening) as insurance against future unreported leaks and to reduce maintenance costs. This should be done in conjunction with almost all the above measures.

References1. Best Practice Guide for Clubs by Sydney

Water Corporation, Section 2.2. Public Amenities a fact sheet by Sydney

Water Corporation.3. Water Use and Conservation a US

handbook by Amy Vickers, Section 2.4.

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KITCHENS AND KITCHENETTESCommon area kitchenettes present limited opportunities for water savings. The most common kitchenette alcove may well only have a sink, a small under-sink hot water storage tank and a mini boil unit. Some may also have a dishwasher. If a larger tenancy kitchen or canteen is present then more significant opportunities may present themselves in the form of commercial kitchen equipment such a large dishwasher with pre-spray rinse trigger guns and food steamers. Such commercial type facilities are outside the scope of this guide and probably

should be sub metered and deducted from the overall office consumption. The Sydney Water web site provides some valuable information about restaurant kitchen water efficiency.

Water efficiency opportunitiesMeasures that may be available to save water in kitchenettes are:

Tap efficiency measures as above. Flow rates need to be selected to suit the function – hand basins can be limited to 6-8 L/minute while taps and spouts used for pot filling should not be restricted. All taps should be fitted with high quality, long life jumper valves.

Dishwasher replacement with water efficient model (2-3 L/cycle maximum), replace worn, missing or excessively high flow wash nozzles in existing equipment, fit pressure regulator if pressure is excessive and equipment has no built in control and ensure racks are effectively stacked and only full loads are run through.

Fit 7-day timers to mini boil units to achieve energy cost savings for reinvestment in water savings.

Routine check and exercising of hot water tank expansion valves for water and energy savings.

Make leak reporting a responsibility for cleaners.


Water Corporation, Section 3.2. Kitchens a fact sheet by Sydney Water

Corporation.3. Water Use and Conservation a US

handbook by Amy Vickers, Section 4.4.

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technical measures

WATER EFFICIENCY GUIDE: OFFICE AND PUBLIC BUILDINGS2�

OUTDOOR AND LANDSCAPINGIrrigation water use can vary greatly from 1-20% of total building water consumption, depending on the facility and the amount of open space. CBD facilities would be at the lower end of the scale, whereas regional and landmark buildings with large external areas could well be much higher (such as in Canberra).

Water efficiency opportunitiesSome or all of the following measures may be suitable:

Install efficient irrigation systems such as drip irrigation, soil soakers, and efficient sprinkler systems.

Check that sprinklers water the garden only, not the street or footpaths and support with signage.

Water the lawn only when the ground is dry and preferably no more than once a week.

Adjust watering schedules for the season.

Water during the coolest part of the day (preferably morning) and never

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water on windy days. As much as 30% of water used can be lost to evaporation by watering lawns at midday.

Install rain/moisture and wind sensors to shut off irrigation systems.

Remove weeds to decrease competition for water.

Use a mowing height of 50mm to 75mm (2-3 inches) and apply mulch to both reduce evaporation and prevent weed growth.

Limit grass areas and use native trees, shrubs, and other plants that require less water (xeriscape). Grass requires 30-50% more water than shrubs and other groundcovers.

Repair or replace leaking hoses and sprinklers.

Always use an automatic shut-off nozzle on hoses.

Use a broom rather than a hose to clean decks, footpaths and paved areas.

Collect rainwater, cooling tower bleed off and/or fire system test water for reuse on landscaping if higher end uses are not feasible.


Water Corporation, Section 7 ‘Outdoor Areas’.

2. Outdoor Areas a fact sheet by Sydney Water Corporation.

3. The Water Efficient Garden a guide by Wendy van Dok.

4. Water Use and Conservation a US handbook by Amy Vickers, Chapter 3.

RETAIL AREASThese can include high water use ‘food outlet’ type facilities such as food courts or restaurants; however, these specialist end uses are outside the scope of this office guide. These areas and/or the office consumption should be submetered so this retail consumption can be subtracted from

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Carpark centre vegetation swale at the Reservoir Civic Centre.

Mulch reduces outdoor water use at Reservoir Civic Centre (Darebin City Council, VIC).

technical measures


the main meter readings. Separate guidelines need to be followed (although some from this guide will be useful) to address what can be very water intensive activities. The Sydney Water web site provides useful information and suggestions for retail facilities.

OTHER WATER EFFICIENCY AND CONSERVATION MEASURES

Pressure reduction Premises with excessive system pressures are prone to frequent leaks and flows in excess of requirements. System pressures as high as 1400 kPa have been recorded in some low lying areas of Sydney. Many facilities operate reasonably well at 250-300 kPa and 500 kPa is considered the maximum needed for most buildings. The system pressure should be checked at various points in and around the building, certainly at the top of multistorey buildings as reducing excessive pressure in the ground floor may result in low pressure at higher levels. These checks can be arranged with the water supplier, plumber or by purchasing a simple pressure test kit at a plumbing supply store.

The feasibility of installing a pressure reduction valve on the potable water (not fire) line should be investigated if ground level pressures are much over 800 kPa. Water savings will result, system maintenance costs will be cut and equipment life should be extended. OH&S issues such as water splashing from basins onto tiled floors will also be resolved.

Fire systemRoutine fire system testing can require the bleed off of significant quantities of water. This high quality water normally goes to the storm water drain. If it can be captured in a closed system prior to going to drain there is no reason it cannot be reused for the fire system

or cooling tower make up water. The feasibility of piping the test flows to a storage tank should be investigated – some sites may well already have a suitable fire water holding tank. Fire hose reels and hydrants should be inspected regularly for leaks and unauthorised use (such as loading dock wash down).

Rain water harvestingRain water from roofs can be captured and stored in ground floor or basement tanks (20000L being a useful capacity). If it is to be used to supply drinking water taps, showers and hand basins, subject to local regulations, it must be passed through self cleaning filters before being treated by UV disinfection filters. Continuous quality monitoring should only bring on treatment systems (possibly including chemicals) when required so as to minimise energy costs. Excess water can flow to the stormwater system as usual or to a grey water system for use in toilet flushing, irrigation, vehicle washing or other approved uses. Alternatively, rain water could be used directly for toilet flushing, irrigation and vehicle washing, possibly without any treatment.

Grey water Grey water from basins, sinks and showers can be collected and settled in ground floor or basement tanks. Fire system test water could also be added to the tanks if it cannot be returned to the fire system or used in cooling towers. Treatment should include biological trickle filters, clarifier, self cleaning filtration, UV filter disinfection and chemical treatment via a water monitoring system. Treated water can be reused for such purposes as water closets, urinals and landscape irrigation but is subject to regulations and standards set by local authorities. Such systems can be interconnected (via a back

flow preventer) to the potable water supply, but with the connection point down stream from the rainwater tanks so that potable mains water is not wastefully treated again on site. Excess water would flow to the sewer system as usual.

The ‘60 L’ building in Melbourne has implemented many water efficiency and reuse initiatives in a refurbished office building setting. (http://www.60lgreenbuilding.com/#). Lend Lease’s new headquarters at 30 the Bond in Hickson Road, Sydney uses a rain water collection system to water an extensive roof top garden. The Department of the Environment and Heritage has implemented a range of water reuse initiatives at its main site, the John Gorton Building in Canberra. A grey water system is used to irrigate the grounds through a root guard, in-line sub-surface dripper system.

Storm water Storm water tanks can be used to collect run-off that would otherwise go to the local piped system. It can then be used for irrigation and local wetland charging. This may well only be feasible for new building projects. Some filtering would be necessary to collect water borne debris that might clog the tank and any reticulation system.

Installation of water storage tank at Reservoir Civic Centre.

case study


INTRODUCTIONSignificant steps have been taken to demonstrate Victorian based Department of Primary Industry’s (DPI) commitment to sustainability through the introduction of their ‘State-wide Sustainable Corporate Real Estate Program’ which incorporates the application of Ecologically Sustainable Design (ESD) concept and principles. This commitment incorporates the sustainable management of all DPI assets, including the Corporate Real Estate portfolio comprising approximately 900 buildings and facilities on 82 sites throughout Victoria. Three of DPI’s properties in particular reflect innovative design for water efficiency and water pollution risk reduction. Water efficiency is just one small component of the environmental initiatives in this programme, which takes a more holistic approach. These examples are nonetheless valuable, and being largely rural, or set in environmentally sensitive areas (near water courses), are thus of particular relevance to building managers or owners in similar locations.

MANAGEMENT AND BEHAVIOURAL MEASURESBuilt into the programme, are measures to:

Maximise value for money for owners, users and the public, and make clients, and in turn suppliers fully aware of their environmental responsibilities.Initiatives to ensure the engagement and support of staff and senior managementConduct a post occupancy evaluation

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one year after the completion of each project to measure building performance, how building users perceived their working environment, to benchmark the study, and to review the cultural, social and community benefits of the new or upgraded facility.

ASSESSING AND REPORTING PERFORMANCEDPI reports environmental performance annually as part of the Whole of Victorian Government Environmental Management System (EMS) and in its own Annual Report.

TECHNICAL MEASURESThrough a shared service with the Department of Sustainability and Environment, DPI has a process of continuous improvement, which includes improved metering at DPI sites and the trial of waterless urinals at sites with more than 100 staff.DPI has also progressively decommissioned cooling towers, and currently have only three still in operation.

On all DPI sites (beyond the three case studies mentioned here) for new developments or redevelopments, flow control systems and low flow fittings have been specified, along with the trial of waterless urinals at sites with more than 100 staff.

RAINWATER CAPTURE AND RE-USE AT DPI ELLINBANK CENTRE:As this site is located in a rural area, it has no access to town mains water. Therefore all rainwater is collected and stored in tanks and an overflow dam. Water from the dam and nearby creek is used for the back-up air-conditioning system, which operates when the thermal labyrinth is ineffective due to climatic conditions.

RAINWATER CAPTURE FOR REUSE/WETLAND CREATION FOR STORMWATER + RUNOFF TREATMENT AT DPI QUEENSCLIFF CENTRE: This centre comprises office, conference and educational accommodation, teaching and research laboratories, and workshop and pump houses. As this major new site was constructed on a former municipal landfill site, there was environmental and community concern that run-off would affect the internationally recognised Swan

DPI Ellinbank, DPI Queenscliff and DPI Horsham Centres

Building Type: Redevelopment of existing research/office/public facilitiesClimate: TemperateLocation: Rural and semi rural VictoriaClient: Department of Primary Industry VictoriaProject Manager: Atkinson Project Management, Johnstaff Pty LtdArchitects: Lyon Architects, Clarke Hopkins ClarkeEngineers: Arup, Irwin ConsultSize: 2�35m², 4�� m², �� m².

DPI Queenscliff.

DPI Ellinbank.

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PROFORMA 19.05.06

Bay alongside. Therefore a 175 000 litre tank was installed to catch rainwater for fire fighting and irrigation purposes, and any excess stormwater and run-off is directed to a specially designed two-stage wetlands, which naturally filters the water as it seeps back into Swan Bay.

WETLAND CONSTRUCTION FOR RUNOFF TREATMENT AND IRRIGATION AT DPI HORSHAM CENTREThe north west of Victoria has suffered from years of drought as well as a history of some inappropriate farming practices over the years. This has resulted in the local Wimmera River effectively becoming a closed system. As part of the redevelopment at Horsham, DPI constructed a large wetlands at the front of the property to collect all non-sewer run-off. This is particularly important for the run-off from the glasshouses, which is high in nutrients used to promote plant growth. Water from the wetlands is now used for the irrigation of the native gardens around the site. In combination with the anticipated Wimmera Mallee Pipeline Project, which will increase environmental flows in the river, these actions should see the Wimmera River restored to its former glory.

The DPI Queenscliff research facility in Victoria minimised its impact by providing for regeneration, provision of habitat and minimal site disturbance. This involved the remediation of the site and the construction of wetlands.

Queenscliff Ecocentre, DPI Victoria.

PAY BACK PERIODWater efficiency is a management and moral imperative, especially in a rural area, making payback periods less significant in this situation.

FOR MORE INFORMATIONContact Kent Schubert. Manager: Capital Projects Infrastructure and Facilities Management Branch Department of Primary [email protected]

REFERENCESSchubert, K. (2006). Achieving

Sustainability in Corporate Real Estate. A paper submitted for Enviro06 conference, held in Melbourne, Australia, 2006.

DPI Queenscliff.


management and behavioural measures

Table 2: non-technical KRAs.

Management and behavioural measures3.0

MANAGEMENT FRAMEWORKTo achieve best practice in water management and to continuously improve, a range of non-technical measures needs to be undertaken. Technical measures can only achieve so much - the attitudes, behaviour and competency of people using them also have a significant bearing on efficiency and conservation. Non-technical measures can be usefully categorised using one of the following six Key Result Areas (KRAs):

1. Planning2. Leadership3. Awareness4. Measurement5. Process6. Supply

A range of behavioural and/or management-related water efficiency measures is possible for each KRA. However, it is necessary for them to be applied in accordance with a well reasoned strategy and plan that reflects the specific facility and the nature of the stakeholders. Suitable measures for each KRA could include the following:

KEY MEASURESAll of the measures and actions identified for each KRA will need to be addressed in some detail. The following provides some extra guidance on arguably the five most important areas of best practice water management.

Water management planA water management plan (WMP) is essential to achieving effective and sustainable outcomes – fail to plan, plan to fail. Table 1 provides the outline for an effective WMP. The plan should not be overly complex or verbose. Ideally it would form part of a wider Environmental Management System (EMS) developed in accordance with ISO14001, which addresses wider Ecologically Sustainable Development (ESD) issues. It should be seen as a practical tool with ownership taken at all levels. Plans that end up filed away, never to see the light of day, are useless.

Water monitoringConsumption data from water bills is of limited value. Time of use data based on 5-minute recordings is needed to properly analyse end uses, especially leaks and excessively high intermittent flows. A single meter at the boundary is also usually insufficient. Sub-meters should be installed where feasible on any end use or end use category that makes up more than about 20% of total consumption. For high use sites, at least the main meter should be continuously monitored online either via the BMS or a web-based water information service.

1. Planning 2. Leadership

•policy statement •management organisation structures•principles to be adopted •roles•goals to be achieved •responsibilities•strategies to be followed •accountability •management and implementation •change management plans•plans necessary to achieve outcomes

3. Awareness 4. Measurement

•motivation •measurement•education •data collection, collation and analysis•training •key performance indicators•innovation •benchmarking•participation •performance reporting

5. Process 6. Supply

•management practices •costs•operational and work methods •tariff information•standards and guidelines •reliability•procedures •quality •business cases •data supply•approvals and funding •demand management assistance mechanisms


management and behavioural measures

RefNo.

Title Details

1.0 Introduction •application and scope•aim and purpose•policy and management framework•goal•principles

2.0 Stakeholders •name•stake•risk/impact•responses•engagement

3.0 Baseline data, KPIs and targets

•building description•major systems and equipment•energy supply – metering and tariffs•consumption history•end uses and users•consumption drivers and KPIs•benchmarks and targets

4.0 Audits and savings measures

•audit methodology and scope•technical efficiency measures•conservation measures

5.0 Management performance •key result areas•assessment criteria and scoring•risk assessment•management action plan•management committee

6.0 Implementation •procurement mechanism(s) •funding and approvals•programme•budget•resources

7.0 Performance reporting •recipients•responsibility and accountabilities•scope, measures and targets•frequency

KPIs and benchmarkingConsumption drivers need to be identified that consistently impact end use. For offices it has been shown that the net lettable area (NLA) of the building has the best correlation with consumption, with correction needed for the impact of cooling degree days for different climatic regions. This means the L/m2 per year KPI is most indicative of the true efficiency of office water use. Other useful, more micro KPIs to consider might include L/m2 air-conditioned area per year and L/m2 air-conditioned area/operating hour for cooling towers. The latter focusing on plant performance, the former will include the impact of annual operating hours.

Change management and communications planTo effectively implement the non technical measures, an integrated change and communication management plan can be useful. For each of the stakeholders, both the existing and the required behaviours and responses need to be documented. The barriers need to be defined and appropriate strategies developed to overcome them. Many measures are best combined with others or implemented in a certain sequence for maximum effect. Suitable measures could include:

education and traininginformation in the form of guidelines, fact sheets, case studies, workshopsconsultation via workshops and questionnairesincentives such as rewards, awards, recognitionfeedback via KPIs versus targets, benchmarking against others, newsletters, CEO memos, emails, stickers near the measures and website notices.

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References1. 7-Point Plan for Water Conservation by

Sydney Water Corporation.2. Pathways to Sustainability an information

kit by South East Water, Yarra Valley Water and City West Water.

3. Water Savings Action Plans a guideline by Department of Energy, Utilities and Sustainability NSW.

4. Water Auditing and Conservation by Jeffery Sturman, Goen Ho and Kuruvilla Mathew.

5. Water Use and Conservation a US handbook by Amy Vickers, Chapters 1 and 4.

Table 3: outline for an effective WMP.


asessing and reporting performance

Assessing and reporting performance4.0

CONSUMPTION PERFORMANCE

Baseline consumptionAn early task in a WMP is to establish a baseline of facility information and data. This should include at least quarterly consumption data for the last 1-2 years, shorter interval data is better for problem analysis (such as monthly, daily, 5-minute interval). This should be adjusted as best as possible for any abnormalities (such as water restrictions, major leak, significant vacancies) so as to give a realistic reference or baseline against which to measure the effectiveness of future savings measures.

Performance indices and benchmarkingA consumption index or benchmark is also needed to measure performance effectively.

Office buildingsThe most appropriate tool to use to benchmark the water intensity of existing office buildings is NABERS OFFICE Water. The NABERS OFFICE ratings are based on actual data related to the performance of an office premises over the last 12 months. To make this real-life performance data comparable with other sites, certain adjustments are made to take into account the specific nature of the site to make the comparisons relevant and realistic. The adjusted data is then compared to benchmark data, and a rating score reflecting the performance of the building relative to the market is calculated. The cost of an accredited rating will depend on the type of rating you are undertaking, the size of the building, and the difficulty of gathering the appropriate data. NABERS OFFICE Water uses the same methodology as the industry standard benchmark for

energy and greenhouse performance, the Australian Building Greenhouse Rating (ABGR) scheme. A current ABGR rating for the premises makes a NABERS OFFICE Water assessment simple. A NABERS OFFICE Water rating is based on the size and occupancy of the premises, which is the same information used to work out the ABGR rating for the premises. The only additional data needed to undertake a NABERS OFFICE Water rating is water bills covering the last 12 months. See Table 5 for NABERS water benchmarks for office buildings, by major metropolitan centre. Refer to www.nabers.com.au for further information, and to undertake a NABERS rating.

The 2005 office and public building water benchmarking study by the DEH showed conclusively that for office buildings the most appropriate index is one based on net lettable area (NLA) in the form of kL/m2/year. There has been a tendency to use an occupancy based index (ie kL/person/year) however the above DEH study of some 132 office buildings showed that the coefficient of correlation (r2) between water consumption and occupancy was only an insignificant 0.0008 versus 0.6899 for NLA (where 1.0 indicates complete correlation between two variables).

For office buildings with other significant water end uses such as retail food courts, these uses will skew the index thereby making it impossible to benchmark performance. This is why it is important to install submetering so that such non-office loads can be deducted.

Data from the recent DEH Office and public buildings water intensity benchmarking study showed best practice indices of 500 L/m2 per year with an average of 1 125 L/m2 per year

and a median of 910 L/m2 per year. Worst case performances as high as 3500 L/m2 per year were observed.

Another existing building rating tool is Green Star – Office Existing Building. The tool rewards buildings for water-efficient fixtures, water reuse, use of water meters, water-efficient landscaping, efficient cooling towers, and reduced fire system water consumption. Water efficiency is only one component of a larger rating tool that addresses the environmental performance of the entire building. For more information visit www.gbcaus.org

Public buildingsThe DEH Office and Public Buildings Water Benchmarking study sample for public buildings was too small to conclusively determine the consumption driver with the best correlation with consumption. However, based on the sample set of 17 buildings, the NLA/consumption correlation was shown to be 0.86 which is similar to that indicated for office buildings. In the absence of any better data it would seem that an NLA based index is also applicable for public buildings.

The data indicated the average performance for these buildings was 3400 L/m2 per year and that a suitable best practice target should be 2000 L/m2 per year.

The Institute of Sustainable Futures has conducted some interesting national and international investigations into just what best practice measures can achieve. A useful paper from the ISF can be found on their web site.http://www.isf.uts.edu.au/publications/VC_SW_CH_MJ_2003.



Fire sprinkler water savings Every week the fire pumps in commercial office buildings are tested, as required under OH&S regulations. To test compliance, each of the pumps has to run for �0 minutes at maximum speed. Thousands of litres of water are typically flushed into the stormwater drains as a result of this procedure. At �0 Pacific Highway, Investa has installed a water saving system where the water is directed into a tank and then recirculated. From this building alone, this initiative will save hundreds of kilolitres a year. (Investa 2005 Sustainability Report, p21).

First commercial offices rated using NABERS OFFICE Water.

Since the launch of the NABERS OFFICE Water tool on 3 April 2006, Australian companies have begun working to have their commercial office water consumption rated using this innovative tool. Investa Property Group is the first company to obtain an accredited NABERS rating, benchmarking their national portfolio using NABERS in June 2006. Table 4 highlights some of Investa’s initial rating results.

NABERS OFFICE Water Star Rating

Site

3.5 �2 Northbourne Ave, Canberra City ACT 2�0�3 23� Elizabeth St, Sydney NSW 20003 2�0 Elizabeth St, Sydney NSW 20003 55 Market St, Sydney NSW 2000

3.5 � Market St, Sydney NSW 20003 300 Elizabeth St, Sydney NSW 2000

3.5 3�0-322 Pitt St, Sydney NSW 20003 3� Market St, Sydney NSW 20004 �0 Pacific Highway, North Sydney NSW 20�0

Table 5: Investa’s initial NABERS rating results.

Fire pump and sprinkler testing Investa is applying a new industry standard for sprinklers and fire pump sets that allows monthly testing instead of the previous weekly regime, which is expected to deliver major savings (Sydney Water. The Conserver: Investa High benchmark for low water use. Issue 10, page12, May 2006 Business Bulletin).

Table 4: NABERS benchmarks for office buildings(kL/m2/year).


1 star 1.73 1.03 0.99 1.08 2.53 1.41

2 stars 1.39 0.86 0.83 0.9 1.99 1.14

2.5 stars 1.21 0.77 0.75 0.8 1.72 1.01

3 stars 1.04 0.69 0.67 0.71 1.44 0.88

3.5 stars 0.87 0.6 0.59 0.62 1.17 0.75

4 stars 0.7 0.53 0.51 0.53 0.9 0.61

4.5 stars 0.52 0.43 0.43 0.44 0.62 0.48

5 stars 0.35 0.35 0.35 0.35 0.35 0.35



All criteria at each level for any given KRA should be satisfied before that level is considered achieved for that KRA. An unbalanced matrix probably indicates that resources are being wasted and efforts may not be effective in all areas. An imbalance of 2 or more performance levels should lead to a focus on those lagging areas. In Figure 8 this would obviously apply to the ‘measurement’ KRA.

In addition to a WMP, the following non technical measures should have suitable assessment criteria developed and included in a management performance matrix:

policy and senior championsmanagement accountability and responsibilitytraining and educationcommunications plansubmetering, time of use monitoringconsumption information managementbusiness cases and access to fundssupply agreement/tariff review.

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The following figure shows how performance levels for each KRA can be reported simply and graphically to give a clear overall score card for water management.

Figure 8: management performance matrix.

Water Efficiency GuidelinesOffice and Public Buildings

DEH Water Efficiency Guide Anne's edits Page 35 of 37

The following figure shows how performance levels for each KRA can be reported simply and graphically to give a clear overall score card for water management.

Fig. 11: Management Performance Matrix

Key Result Areas

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f Pe

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ce

1Planning

2Leadership

3Awarenes

4Measurement

5Investment

6Supply

Best Practice

Leader

Average

Moderate

Low

5

4

3

2

1

All criteria at each level for any given KRA should be satisfied before that level is considered achieved for that KRA. An unbalanced matrix probably indicates that resources are being wasted and efforts may not be effective in all areas. An imbalance of 2 or more performance levels should lead to a focus on those lagging areas. In Figure 11 this would obviously apply to the ‘Measurement’ KRA.

In addition to a WMP, the following non technical measures should have suitable assessment criteria developed and included in a management performance matrix:

Policy and senior champions;

Management accountability and responsibility;

Training and education;

Communications Plan;

Sub metering, time of use monitoring;

Consumption information management;

Business cases and access to funds; and

Supply agreement/tariff review.

PERFORMANCE IN WATER MANAGEMENT PRACTICESThe performance for each of the non-technical management KRAs covered in Section 3.0 can be quantitatively determined using a series of assessment criteria or questions for each KRA to establish which of the following levels have been achieved for that KRA (Table 6):

5 Best Practice4 Leader3 Average2 Moderate1 Poor

The criteria used to assess performance will depend on the nature of the facility, its end use and the ultimate level of performance sought. The following provides sample questions for each performance level for the ‘planning’ KRA using the status of a Water Management Plan as the subject. Table 6: sample assessment criteria - ‘Planning KRA’.

Level Evaluation Criteria

5

4

3

2

1

WMP reflected in Landlord’s and Tenants’ Business Plans, high level of awareness, stakeholders’ proactive contributions logged and reported, KPIs reviewed annually with targets met or exceeded, plan considered a benchmark.WMP regularly reviewed, no QA audit non compliances, monthly progress reports to senior management demonstrate achievement of goals and targets, principles being consistently adhered to.WMP complete and signed off, baseline information and data established, Plan accountabilities and responsibilities clearly assigned, resources allocated.WMP framework finalised addressing issues, risks, goals,etc all coordinated with wider ISO 14001 EMS by both landlord and tenant.Need for WMP acknowledged by senior management, part of formal short-term action plan.

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PROFORMA 19.05.06

MANAGEMENT AND BEHAVIOURAL MEASURESUnderpinning the aforementioned water savings are not only technical alterations to the physical building structure, but also a host of management initatives.

Investa has adopted a sustainability framework, in recognition of the contribution sustainability can bring to business, which includes the adoption of a Sustainability Policy as well as establishing an Environmental Management System to the requirements of ISO 14001. In addition, Investa, in partnership with local water utilities such as Sydney Water and Melbourne water retailers, investigates opportunities for progressively reducing water consumption in buildings. Water usage is monitored, reduction targets set, and performance reported annually in Investa’s Sustainability Report. In 2003, Investa joined Sydney Water’s Every Drop Counts Business Programme with the aim to reduce water consumption by 25% within 3 years, and exceeded this target before time. Other managerial changes include the public disclosure of water management targets and Australian Building Greenhouse Ratings, as well

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as the establishment of a Green Lease provision. The Green Lease is best described as a precedent lease (one which forms the basis for all tenant lease negotiations) which sets out mutual obligations of building owner and tenant to achieve environmental improvements. Tenants have the choice as to whether or not to agree to meet these obligations, the benefits of which include decreased running costs for tenants. From a building owners perspective, benefits include the opportunity to attract future tenants through lower running costs and generating more appealing buildings to work in.

ASSESSING AND REPORTING PERFORMANCEMetering of water use across a significant proportion of Investa’s properties enables the capture of data required to generate figures to indicate water use intensity in terms of kL/m2/year, as well as annual volumes of water consumption for specific buildings and across the portfolio. Investa publicly discloses water efficiency targets, and produces a publicly available sustainability report annually to report on progress towards reaching targets.

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INTRODUCTIONInvesta Property Group is the largest listed owner of commercial property in Australia. It has demonstrated its commitment to sustainability in the management of office buildings through a variety of managerial and technical based projects across their portfolio, both independently and through partnerships with the Sydney Water Every Drop Counts Business Programme and the Sustainable Melbourne Fund.

As a result of these efforts, a 25.8% water saving was achieved in the two years to 31 March against 2003 base year participating sites (12) in Sydney (NSW) and Melbourne (Vic). The consequent average water intensity per square meter for these sites amounted to 1.159 kL/m2/year, and with newer sites being added to the programme in 2004-5, average water use intensity has fallen by 13.2% to 1.008 kL/m2/year. These water intensities are closest to an unofficial 3 star NABERS rating, indicating above average performance for water use in buildings. Future targets involve achieving an average water use intensity of 0.92 kL/m2/year by 31 March 2007 for assets under the Investa water programme.

Investa Property Group

Building Type: Retrofit of existing office blockClimate: TemperateLocation: Various across city locations in NSW and VictoriaClient: VariousProject Manager: Craig Roussac

case study


TECHNICAL MEASURESWater monitoring systems have now been rolled out across all buildings in the NSW portfolio of Investa properties to provide accurate ‘real time’ accounts of a building’s water use. This system measures water usage every 30 minutes and identifies the source of the water use. With assistance of Sydney Water, Investa completed audits on 15 of its commercial properties, which alone identified savings of 43% for each building, representing a total water saving of 617 kilolitres a day. Investa is considered a pioneer in the realm of water efficiency initiatives among commercial property owners in Australia. Initiatives tackled thus far on Investa properties include Investa switching from traditional to waterless urinals across 31 buildings in the first quarter of 2005. This initiative involves installing waterless urinal cubes which allow the treatment of urine within urinals without the use of water. Given the water supply to urinals can be switched off, a typical waterless urinal saves over 150 kilolitres per year. That equates to a massive 50 000 litres per day or approximately half a 50 metre municipal swimming pool. In addition to water savings, benefits include:

reduced odours and fresher smelling urinalsprevention of mineral salt encrustation, improving hygienechemical free cleaning.

•

•

•

PAYBACK PERIODAccording to Investa’s OHS and Environmental Manager Craig Roussac, the annual cost per urinal for waterless urinal cubes is roughly the same cost as the water required to flush a urinal annually, making it effectively cost neutral. While more vigilant cleaning is required, extra costs associated with cleaning may be offset with a reduction in maintenance requirements. This is because under such a waterless urinal system, the water supply can be turned off completely, removing not only the cost of water use, but also the added cost of water used resulting from leaks, and also the maintenance to fix leaks.Other amenities related initiatives include:

modifying motion sensors in urinalsadjusting toilet flush volumes or replacing toilet cisternsinstalling flow restrictors on showers and tapsidentifying leaks.

FOR MORE INFORMATIONCraig Roussac, Head of Environment, Health and Safety. Investa Property Group, [email protected]

REFERENCESInvesta Property Group 2005 Sustainability

Report. http://www.investa.com.au/Common/Pdf/

CorporateGov/sustain_report_2005.pdf Sydney Water (2006). The Conserver:

Investa High benchmark for low water use. (Issue 10, May 2006 Business Bulletin).

••

•

•

Craig Roussac, Head of Environment, Health & Safety (middle) with colleages of Investa Property Group.

Investa Property Group


references and links

References and links5.0

Web SitesAustralian Government, Department of the Environment and Heritage www.deh.gov.au/settlements/government/water-efficiency.html

Australian Government WELS site www.waterrating.gov.au

Australian Water Association www.awa.asn.au/

Cooling Tower Institute USA www.cti.org

Facilities Management Action Agenda www.fmactionagenda.org

Facility Management Association of Australia Ltd. www.fma.com.au

International Water Association www.iwahq.org.

National Australian Built Environment Rating System www.nabers.com.au

NSW Department of Energy, Utilities and Sustainability www.deus.nsw.gov.au/water/water.htm

South Australian Government www.environment.sa.gov.au/sustainability/water_resources/index.html

South East Water (Vic retailer) www.southeastwater.com.au

Sydney Water Corporation www.sydneywater.com.au/SavingWater

Victorian Government Water Efficiency www.savewater.com.au

Water Services Association of Aust www.wsaa.asn.au

Reference BooksMcKenzie-Mohr, Doug. Fostering Sustainable Behaviour. New Brunswick: New Society, 1999. Sturman, Jeffery, Goen Ho and Kuruvilla Mathew, Water Auditing and Conservation. London: IWA Publishing, 2004. Van Dok, Wendy. The Water Efficient Garden. Glen Waverley, Vic: Gardenscapes, 2000. Vickers, Amy. Handbook of Water Use and Conservation. Amherst, MA: Water Plow Press, 2001.

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••

••


Water Intensity Benchmarks for Offices and Public

Buildings

�� September 2005

Dr Paul Bannister, Michael Munzinger and Chris Bloomfield

Exergy Australia Pty LimitedABN 5� 0�� 33� ��Unit H, 5�-�� Lathlain Street Belconnen ACT 2��PO Box 54� Belconnen ACT 2��t +�� 02 �25� �0�� f +�� 02 �25� �0�3 www.xgl.com.au

Publication InformationTitle: Water Benchmarks for Offices and Public BuildingsAuthors: Dr Paul Bannister, Michael Munzinger and Chris BloomfieldReference: XA-CR-�32Edition: �.2


APPENDIX:

Water Intensity Benchmarks for Offices and Public Buildings

CONTENTS

Executive Summary�.0 INTRODUCTION Background 2.0 METHODOLOGY Data sample characteristics Characteristics of the office building sample Characteristics of the public building sample 3.0 BENCHMARKING ANALYSIS – OFFICE BUILDINGS Primary benchmark derivation Influence of technical factors Financial information Derivation of rating bands Comparison with overseas benchmarks Further work 4.0 BENCHMARKING ANALYSIS – PUBLIC BUILDINGS Primary benchmark Comparison with overseas benchmarks Further work 5.0 CONCLUSIONS �.0 DATA COLLECTION FORMS Office building data collection form Public building data collection form

404�4�4242434445454�4�505�5�5252525253545454


This report summarises findings of a study undertaken by Exergy on behalf of the Department of the Environment and Heritage into the water consumption of office building and public buildings in Australia. This project was jointly funded by the Australian Government and the governments of Western Australia, South Australia, Victoria, the ACT, New South Wales and Queensland.

Data on water consumption and water consumption features was gathered from 132 office buildings and 18 public buildings around Australia.

OFFICE BUILDING WATER CONSUMPTIONOffice building water consumption intensity (water consumed per m²) was shown to be approximately constant relative to identifiable technical and operational features of the buildings but subject to significant climate effects. To create a water consumption benchmark, the following process has been developed:

Water consumption intensity in kilolitres per m² W is normalised for climate via the following equation to become normalised water consumption intensity N:

Executive summary

Wcorr= 0.516158 - 0.001038CDD15wbN= W+Wcorr

Where CDD15wb refers to cooling degree days calculated to base 15ºC wet bulb. The normalised water consumption intensity can then be assessed on the following scale, which has been designed to follow the same scoring methodology as the National Australian Building Environment Rating system and the Australian Building Greenhouse rating scheme.

Assessment of the deviation of the raw water consumption data from the median climate corrected benchmarks indicated no statistically significant influence on water consumption from any of the following factors:

occupant density of buildingshours of use of buildingsuse of water cooled chillersexterior water features and irrigation systemswater management practices and systemswater pricing.

In most cases, there is also no discernable difference in median water consumption either. Only in the case of water cooled chillers does it appear likely that a larger data set would ultimately yield a statistically significant result.

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•

•

PUBLIC BUILDING WATER CONSUMPTIONThe small size of the public buildings sample dictated a simple benchmark approach. An average water consumption intensity of 3.34 kL/m² per annum and a best practice target of 2 kL/m² per annum have been identified based on the data. It would be desirable to supplement this benchmark with additional data to ensure its full validity.

FURTHER WORKIt has been recommended that, should further data collection be considered, it should focus on office building data in climates from Brisbane to the tropical regions, and on Western Australia. Any further data for public buildings would also be useful.


introduction

Introduction

This report summarises findings of a study undertaken by Exergy on behalf of the Department of the Environment and Heritage into the water consumption of office buildings and public buildings in Australia.

BACKGROUNDWater consumption has become a defining environmental issue for Australia in the first decade of the 21st century, with drought conditions causing near-universal restrictions in temperate areas and placing pressure upon infrastructure.

The built environment, although dwarfed by agricultural water consumption, represents a major consumer of the potable water that is managed through man-made infrastructure such as dams. As a result, there is significant pressure to reduce water consumption in the built environment to decrease the stress on the potable water infrastructure.

For commercial buildings, recent investigations have demonstrated that there is little knowledge as to what constitutes good or bad performance with respect to water consumption. This lack of knowledge is a barrier that inhibits the ability of the market to respond to poor performance with appropriate actions.

1.0

The purpose of this benchmarking project is to develop benchmarks for office buildings and public buildings in a manner that is compatible with the performance–based approach used in the Australian Building Greenhouse Rating scheme (ABGR) and the National Australian Built Environment Rating System (NABERS). Both ABGR and NABERS range from 1 star to 5 stars, with half stars, where 2.5 stars is average, 5 stars is exceptional and 1 star very poor. In both cases, the rating scale is based on the statistics of the building population, thereby ensuring its relevance to the market.

methodology


2.0

Methodology

The methodology used for this project is as follows:

The Department of the Environment and Heritage identified a number of public-sector stakeholders, mainly representatives of state governments.These stakeholders nominated a range of buildings for inclusion in the study. These were generally government owned buildings;

•

•

Table 7: geographic distribution of data.

State Office buildings Public buildings

ACT 22 12

NSW 43 1

VIC 21 3

QLD 16 0

WA 9 2

SA 22 0

Total 132 18

Table 8: data sources. Note that some buildings marked as being government portfolio are actually government leased rather than owned properties.

Jurisdiction contact Office buildings Public buildings

Australian Government, Department of the Environment and Heritage

Government portfolio – 5 Government portfolio – 6

Environment ACT Government portfolio – 6 Government portfolio – 6

NSW Department of Energy Utilities and Sustainability

Government portfolio – 7Mirvac – 22 Colonial First State – 26Investa – 23ING Real estate – 5

Government portfolio – 1

VIC Department of Environment and Sustainability

Government portfolio – 9 Government portfolio – 3

QLD Department of Public Works


WA Government Government portfolio – 1 Government portfolio – 2

SA Department of Environment and Heritage


however one jurisdiction provided contacts to private sector portfolios as their primary data source.A data collection form was developed covering all the key issues, plus some ancillary issues, associated with water consumption.The data form was sent out to the various sites or portfolio contacts nominated by the stakeholdersSite and portfolio contacts were

•

•

•

contacted regularly over an approximate 8 week data collection period.Data was assembled and processed.Through this process, data was gathered on a total of 132 office buildings and 18 public buildings nationwide.Copies of the data collection form are provided at the end of this appendix.

DATA SAMPLE CHARACTERISTICSThe geographic distribution of the data is as shown in Table 7. While the total sample size is good, there is inadequate data to formulate state-specific benchmarks with sufficient certainty. As a result, the analysis focuses on national benchmarks for performance.

The sources of data, cross linked to the stakeholder responsible for the initial contacts are as listed in Table 8. It can be seen that the data collection was aided considerably by the private sector, indicating a high level of market interest in water consumption issues.

•

•

•

methodolgy


CHARACTERISTICS OF THE OFFICE BUILDING SAMPLEThe office building sample covered a wide range of building sizes, as shown in Figure 9. The climate zones for the sample were divergent but heavily biased towards the main centres, as shown in Figure 10.

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Figure 9: office building data - area characteristics.

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Figure 10: office building sample – climate range.

methodology


CHARACTERISTICS OF THE PUBLIC BUILDING SAMPLEThe public building sample was as follows:

Table 9: public building sample.

Site Location Floor area [m2]

Belconnen Library ACT 1596

Canberra Theatre ACT 8350

Dickson Library ACT 1095

National Archives of Australia ACT 5486

National Gallery of Australia ACT 29 500

National Museum of Australia ACT 16 781

Questacon ACT 13 671

National Film and Sound Archive ACT 7876

The Street Theatre ACT 1300

Magistrates Court ACT 10 100

Canberra Museum and Gallery ACT 7677

Woden Library ACT 1954

Australian National Maritime Museum Sydney 14 721

Melbourne Museum Melbourne 17 450

Scienceworks Museum Melbourne 10 069

The Arts Centre Melbourne 41 150

Art Gallery of WA Perth 44 000

R2 = 0.6899

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0 20000 40000 60000 80000 100000

NLA [m2]

Wat

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[kl]

Figure 11: water consumption as a function of floor area.

Table 10: median water consumption intensity for major centres.


benchmarking analysis- office buildings

Benchmarking analysis - office buildingsPRIMARY BENCHMARK DERIVATIONThe office building sample was tested for correlation through the assessment of the coefficient of correlation, or “r²”. The r² value is a measure of the degree to which one variable appears to explain the behaviour of another variable. An r² of close to zero indicates that there appears to be no relationship between the two variables being assessed; an r² approach 1 indicates a strong relationship between the two variables. Note

3.0

however that a high r² is not a guarantee of a causal relationship between variables. However, r² analysis is a reasonable and simple methodology for the assessment of data relationships.

The relationship between annual water consumption and the following key variables was assessed in terms of r² values as listed below:

net lettable area - r² = 0.6899occupant density - r² = 0.0008hours of use - r² = 0.0010cooling degree days - r² = 0.2585

On this basis it was established that net lettable area and cooling degree days form the best basis for the benchmark. The relationship between water consumption and net lettable area is illustrated in Figure 11 below. The reasonably good correlation between the net lettable area and the total water consumption can be seen in Figure 11. On this basis it was considered the most appropriate basis for the benchmark would be water consumption per unit area, corrected for cooling degree days. This cooling degree day correction reflects the increased consumption of water due to heat rejection via cooling towers in warmer climates.

The median water consumption intensity across the entire data set was 0.91 kL/m² per annum. However, this varies from centre to centre as shown in Table 10. It can be seen that there is a general increase in water consumption by a factor of two from cool centres through to warmer centres, as illustrated in Figure 12. This supports the potential value of a climate normalisation.

••••

Centre Median water consumption intensity (kL/m² per annum)

Number of points

Melbourne 0.70 15

Adelaide 0.70 19

Sydney 1.13 39

Canberra 0.72 22

Brisbane 1.56 16

Perth 0.61 9

y = 0.001x + 0.6472R2 = 0.2585

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0 200 400 600 800 1000 1200Cooling Degree Days (base 15°C wb)

Wat

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(kl/m

²)


benchmarking analysis - office buildings

Figure 12: water consumption versus cooling degree days.

In Figure 12, it can be seen that the climate correlation does appear to be substantive. However, the possibility that the climate correction is non-causal has also been investigated by assessing the presence of key water efficiency features against cooling degree days. None of the factors assessed were found to have a significant relationship to cooling degree days, indicating that the climate correction is not caused, for instance, by an excess of air-cooled chillers in Melbourne relative to Brisbane. Given that a climate relationship is expected, due to the impact of cooling towers, it seems reasonable to conclude that the climate correction is causal rather than coincidental.Following the general practice adopted within ABGR, an empirical

climate normalisation has been developed that normalises water consumption effectively to the Sydney median. This means that buildings in Sydney experience no climate correction, buildings in Brisbane are normalised downwards and cold climate buildings are normalised upwards. The normalisation equation is:

Where W is the water consumption intensity in kL/m² per annum, Wcorr is the climate normalisation, CDD is the cooling degree days base 15°C wetbulb (as per ABGR climate correction) and N is the normalised water consumption intensity in kL/m² per annum. The normalised water

consumption figures (in kL per annum) for the sample data has an r² of 81% with floor area.

The distribution of normalised water consumption was tested for secondary correlations to other operational variables. However both hours of use and occupant density showed no correlation (r²<2%) with normalised water consumption intensity. As a result, it is proposed that normalised water intensity is used as the primary benchmark for assessment of water consumption intensity.

Since this research was completed, additional analysis and normalisation by the Department of Energy Utilities and Sustainability has produced the current NABERS rating scale.

Wcorr= 0.516158 - 0.001038CDD15wbN= W+Wcorr

Figure 13: distribution of office building water consumption after climate normalisation.

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INFLUENCE OF TECHNICAL FACTORSData was gathered on the technical factors, as listed in Table 11, that may underlie aspects of the performance of buildings in the sample. These were then subjected to statistical testing to determine the significance of apparent correlations. The results are summarised in Table 11. It can be seen that no factors recorded statistically significant differences, and that in most cases there was no discernable difference even disregarding statistical rigour.

The two factors that show discernable differences – water cooled chillers and exterior water features – may show statistically significant differences if the sample size is increased. At present the small sample size of sites without water cooled chillers (23) or with exterior water features (9) works against statistical significance.

Under the formulation philosophy of ABGR and NABERS, technical factors such as the presence or otherwise of cooling towers are not provided with credit or punishment. As a result, no further analysis of this issue is required.



Table 11: impact of technical factors on water consumption. No statistically significant differences were found.

The interpretation of the results in Table 11 provokes some interesting questions.

Of all the factors, only water cooled chillers show a substantial difference in median from the counter data set (the air cooled chiller buildings) – and yet this factor, which one would consider to be of great importance – does not achieve statistical significance. This lack of significance appears to be caused by the high diversity in the data, such that there are air-cooled chiller buildings with higher water consumption than water-cooled chiller building. In this instance, the presence of a reasonably large difference in medians suggests that, with a larger data set, a statistically significant difference would be likely to be found.

For the other factors the most surprising result is how little effect any appear to have on the median performance. Given the reality that in each case it is known that the individual measure would have an impact on the performance of an individual building, the lack of correlation is at first sight puzzling.

This does not mean, however that the application of water savings measures (for instance) has no impact on water consumption of an individual building. Rather, the impact achieved on such building has not yet been sufficient to differentiate such buildings as a group from the general population. To understand the average savings achieved by, for instance, waterless urinals, one would have to look at before and after performance for individual buildings and average the

change, thereby removing the general ‘noise’ of variability from building to building from the assessment.

FINANCIAL INFORMATIONSample water bills were received from 41 sites across Australia, illustrating a wide range of tariff structures and costs. These were analysed in terms of the incremental cost of water, in $/kL, and the total cost including fixed charges, in $/kL.

There was a large range of costs across the sites in both incremental and absolute terms, as shown in Figure 14. The data certainly indicate that there is little consistency of policy with respect to water charges nationally and that in most areas the fixed charges significantly outweigh the variable charges, providing limited motivation for behavioural change.

Item Median consumption with

item [kL/m2 per annum]

Median consumption

without item

[kL/m2 per annum]

Statistical

significance at 95%

confidence

Features expected to decrease water use

Waterless urinals 1.13 1.13 No

Sensor or manual urinals 1.14 1.11 No

Dual flush toilets 1.09 1.13 No

Submetering of water to major uses 1.13 1.12 No

Formal water management plan being

implemented

1.16 1.10 No

Water audit conducted in past 3 years 1.13 1.13 No

Water saving measures implemented in

past 3 years

1.16 1.07 No

Water savings in response to recent

restrictions

1.13 1.10 No

Features expected to increase water use

Water cooled chillers 1.13 0.95 No

Exterior water features 1.25 1.12 No

Irrigation system 1.13 1.11 No

Figure 14: distribution of the incremental and the total water costs; data points are for individual buildings within the sample for which bills were obtained.

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Figure 15: distribution of the fixed charges share in the total costs.



The possibility that the charging regime for water may have an impact upon the results of this study was investigated by evaluating the r-squared for a number of relationships as shown in Table 12.

It can be seen from Table 12 that there was no relationship between the financial factors and the water consumption or climate, thereby indicating that the impact of water cost on consumption is negligible. Inspection of the strongest relationship (total $/kL to cooling degree days) indicates almost no slope in the relationship, (ie there is little evidence of one variable changing the other).



Water consumption (kL/m² per annum)

Normalised water consumption (kL/m² per annum)

Cooling degree days

Incremental water cost ($/kL)

0.0075 0.0188 0.0019

Total water cost ($/kL) 0.0380 0.0061 0.2032

Table 12: relationships, assessed by r-squared values, between financial factors and water consumption factors.

DERIVATION OF RATING BANDSAs discussed in Section 1, the NABERS rating uses bands that are based on the position of the building within the building population in terms of efficiency. There are a number of rules used to determine the rating bands for a particular population, being:

1. The rating scale should encompass at least 80% of the population2. The mid point score should be based on the population median3. The full mark score should represent a level of efficiency essentially beyond normal

technological solutions, but attainable through innovation4. The rating bands should be linear.

In the inevitable event of conflict between these requirements, the midpoint and linearity rules dominate the setting of the scale.

The application of these rules to the sample can be depicted on the cumulative frequency diagram shown in Figure 16 and as listed in Table 13.

Table 13: proposed rating bands.

Figure 16: cumulative frequency diagram for the sample population, showing proposed rating thresholds.

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FURTHER WORKWhile the sample data size is of a reasonable size, there are some limitations within the data set that pose limitations on the validity of the benchmark. In particular, the lack of data from sub-tropical and tropical

climates means that the extension of the climate normalisation to areas warmer than Brisbane is a pure extrapolation and thus somewhat risk-prone. The first emphasis for additional data collection should therefore be on such climate zones, including Brisbane itself which remains a relatively small sample. Furthermore, it would be desirable to strengthen the data set from Western Australia, as this state is underrepresented in the overall data set.

Rating Water consumption (kL/m2 per annum)

% of sample rating at this level or better

1/5 1.5 80%

2/5 1.25 63%

2.5/5 1.125 50%

3/5 1.0 36%

4/5 0.75 17%

5/5 0.5 5%



Table 14: current NABERS water benchmarks (DEUS).


1 star 1.73 1.03 0.99 1.08 2.53 1.41

2 stars 1.39 0.86 0.83 0.9 1.99 1.14

2.5 stars 1.21 0.77 0.75 0.8 1.72 1.01

3 stars 1.04 0.69 0.67 0.71 1.44 0.88

3.5 stars 0.87 0.6 0.59 0.62 1.17 0.75

4 stars 0.7 0.53 0.51 0.53 0.9 0.61

4.5 stars 0.52 0.43 0.43 0.44 0.62 0.48

5 stars 0.35 0.35 0.35 0.35 0.35 0.35

COMPARISON WITH OVERSEAS BENCHMARKS

Comparatively little work appears to have been done internationally towards that actual characterisation of water consumption as an empirical benchmark. The best example appears to be encapsulated in the UK Watermark programme. This identifies a water consumption benchmark of 9.3 m³ per person per annum and a best practice target of 6.4 m³ per person per annum. Translated at an occupant density of 1 per 18 m² these figures become 0.52 kL/m² and 0.36 kL/m² respectively. Using a notional cooling degree day figure of zero

for the UK climate (by comparison it is noted that Invercargill in New Zealand has 26 cooling degree days to the same base as the benchmark), these figures normalise to 1.08 kL/m² and 0.92 kL/m² (2.7/5 and 3.3/5) respectively. This shows a high degree of comparability in the benchmarks.


benchmarking analysis - public buildings

4.0

Benchmarking analysis - public buildings

PRIMARY BENCHMARKThe benchmarking analysis for public buildings is necessarily simpler than for office buildings because of the small sample size and the diversity of the sample.

The data for public building shows a reasonable relationship between the water consumption and the total floor area, as shown in Figure 17.

On the basis of the regression shown in the figure, it is recommended that a general benchmark for average performance of public buildings is set at 3.34 kL/m² per annum. This benchmark fits the data with an r² of 86%, which is similar to that achieved for the office data set. However, given the smaller size of the data set, the physical diversity of the sites and the uneven distribution of the data points across the data range, the benchmark

is somewhat less well defined than for the offices.

To set a best practice benchmark, the average performance benchmark needs to be reduced until approximately 75% of site use more water than the benchmark. On this basis, the best practice benchmark is 2 kL/m² per annum.

COMPARISON WITH OVERSEAS BENCHMARKSAs with office buildings, there is a shortage of international precedents for water consumption benchmarks in this sector, and the UK Watermark programme provides the best comparison. The programme has two benchmarks relevant to the public buildings sector:

museum and art galleries benchmark 0.332 kL/m², best

•

y = 3.3362xR2 = 0.8627

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Figure 17: water consumption – public office buildings. Hollow data points are outliers that have been excluded from the regression.

practice 0.181 kL/m².library benchmark 0.203 kL/m², best practice 0.128 kL/m².

These figures are notable by the fact that they are lower by a factor of ten than those determined in this study. It is expected that climate has a significant role to play in this, but insufficient data is available to assess this empirically.

FURTHER WORKThe small size of the dataset indicates that there is a good deal of potential for further work in respect to the gathering of additional data, which may in turn yield more information and more detail in the benchmark than is currently apparent.

•

Table 15: NABERS benchmarks for office buildings (kL/m2/year).


conclusions

Conclusions

Data on water consumption for 132 offices and 17 public buildings around Australia has been gathered for the development of water consumption benchmarks.

The office building water consumption benchmark has been established on the basis of a normalised water consumption intensity figure that corrects for climatic impacts. The benchmark has been established in terms that are fully compatible with the NABERS methodology. The benchmark – expressed in terms of the NABERS rating scores, is summarised in the table below:

5.0


1 star 1.73 1.03 0.99 1.08 2.53 1.41

2 stars 1.39 0.86 0.83 0.9 1.99 1.14

2.5 stars 1.21 0.77 0.75 0.8 1.72 1.01

3 stars 1.04 0.69 0.67 0.71 1.44 0.88

3.5 stars 0.87 0.6 0.59 0.62 1.17 0.75

4 stars 0.7 0.53 0.51 0.53 0.9 0.61

4.5 stars 0.52 0.43 0.43 0.44 0.62 0.48

5 stars 0.35 0.35 0.35 0.35 0.35 0.35

For the public buildings, a simple benchmark based on water consumption per unit floor area has been established. The average performance benchmark is 3.34 kL/m² per annum and the best practice benchmark is 2 kL/m² per annum.


appendix

6.0

Data collection forms

Office building data collection form:

Water Benchmarks for Offices and Public Buildings 23Edition: 1.2

6. APPENDIX – DATA COLLECTION FORMS

6.1 Office building data collection form

Site IdentificationBuilding NameSite AddressPostcodeSite Contact NameSite Contact PositionSite Contact PhoneSite Contact Email

Enter Data in the yellow cells - Click in the cells for detailed instructions.Leave the cells blank if you don't have the correct data for a particular question.

Site DetailsYear of Construction / Refurbishment

Site AreasNLA of Office Space (m²)NLA of NON-Office Space (m²)Area of Irrigated Grounds (m²)

Occupancy Area (m²) Hrs/wk

Annual Water Use Note: 1kL = 1 m3Potable Water Use (kL/yr)Submetered Irrigation Water Use (kL/yr)Submetered NON-Office Potable Water Use (kL/yr)External Greywater & Borewater Use (kL/yr)Water Use in Exterior Water Features (kL/yr)

Water Supplier NameSample Bill AttachedTariff

Water Use Features On SiteWaterless UrinalsSensor or Manual UrinalsOther UrinalsDual Flush ToiletsRainwater Re-useGreywater RecyclingExterior Water FeaturesIrrigation SystemWater Cooled Chillers and Cooling TowersDirect Evaporative CoolingCooling Towers for Supplementary CoolingSubmetering of Water to Major UsesFormal Water Management Plan Being ImplementedWater Audit Conducted in Past 3 YearsWater Saving Measures Implemented in Past 3 Years.>>Percentage Savings Achieved by These MeasuresWater Savings in Response to Recent Restrictions>>Percentage Savings Achieved by These Measures

Additional Information

Exergy - April 2005

Water Use Data Collection SheetOffice Buildings

Space IDWeekly Hours of Occupancy / Open Hours (insert additional rows if required)

Total

Exergy Australia Pty Limited XA-CR-132

Public building data collection form:

Water Benchmarks for Offices and Public Buildings 24Edition: 1.2

6.2 Public building data collection form

Site IdentificationBuilding NameSite AddressPostcodeSite Contact NameSite Contact PositionSite Contact PhoneSite Contact Email

Enter Data in the yellow cells - Click in the cells for detailed instructions.Leave the cells blank if you don't have the correct data for a particular question.

Site DetailsType of Site

Year of Construction / Refurbishment

Site AreasTotal Public Space Floor Area (m²)Total Non-Public Space Floor Area (m²)Area of Irrigated Grounds (m²)

Occupancy Area (m²) Hrs/wk

Annual Water Use Note: 1kL = 1 m3Potable Water Use (kL/yr)Submetered Irrigation Water Use (kL/yr)External Greywater & Borewater Use (kL/yr)Water Use in Exterior Water Features (kL/yr)Water Costs Included in Building Budget

Water Supplier NameSample Bill AttachedTariff

Water Use Features On SiteWaterless UrinalsSensor or Manual UrinalsOther UrinalsDual Flush ToiletsRainwater Re-useGreywater RecyclingExterior Water FeaturesIrrigation SystemWater Cooled Chillers and Cooling TowersDirect Evaporative CoolingCooling Towers for Supplementary CoolingSubmetering of Water to Major UsesFormal Water Management Plan Being ImplementedWater Audit Conducted in Past 3 YearsWater Saving Measures Implemented in Past 3 Years.>>Percentage Savings Achieved by These MeasuresWater Savings in Response to Recent Restrictions>>Percentage Savings Achieved by These Measures

Additional Information

Exergy - April 2005

Total

Space IDWeekly Hours of Occupancy / Open Hours (insert additional rows if required)

Water Use Data Collection SheetPublic Buildings

Exergy Australia Pty Limited XA-CR-132

Printed on recycled paper using vegetable based inks by Focus Press, certified EMS ISO 14001.

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