Water Transformed: Sustainable Water Solutions for Climate Change Adaptation

Module B:Adapting to Changes in Water Availability - Industry & Commercial Sectors

This online textbook provides free access to a comprehensive education and training package that brings together the knowledge of how countries, specifically Australia, can adapt to climate change. This resource has been developed formally as part of the Federal Government’s Department of Climate Change’s Climate Change Adaptation Professional Skills program.

Chapter 2: The Fundamentals of Measuring Water Usage, Identifying Water Savings, and Recycling & Water Collection/Storage Opportunities

Lecture 2.4: Identifying & Implementing Water Efficiency & Recycling Opportunities in the Built Environment Sector

© The Natural Edge Project (‘TNEP’), 2009

Copyright of this material (Work) is owned by the members of the research team from The Natural Edge Project, based at Griffith University and the Australian National University.The material contained in this document is released under a Creative Commons Attribution 3.0 License. According to the License, this document may be copied, distributed, transmitted and adapted by others, providing the work is properly attributed as: ‘Smith, M., Hargroves, K., Desha, C. and Stasinopoulos, P. (2009) Water Transformed - Australia: Sustainable Water Solutions for Climate Change Adaptation, The Natural Edge Project (TNEP), Australia.’

Document is available electronically at

Disclaimer: While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the parties involved in the development of this document do not accept responsibility for the accuracy or completeness of the contents. Information, recommendations and opinions expressed herein are not intended to address the specific circumstances of any particular individual or entity and should not be relied upon for personal, legal, financial or other decisions. The user must make its own assessment of the suitability of the information or material contained herein for its use. To the extent permitted by law, the parties involved in the development of this document exclude all liability to any other party for expenses, losses, damages and costs (whether losses were foreseen, foreseeable, known or otherwise) arising directly or indirectly from using this document. This document is produced for general information only and does not represent a statement of the policy of the Commonwealth of Australia. The Commonwealth of Australia and all persons acting for the Commonwealth preparing this report accept no liability for the accuracy of or inferences from the material contained in this publication, or for any action as a result of any person’s or group’s interpretations, deductions, conclusions or actions in relying on this material.

Acknowledgements

The Work was produced by The Natural Edge Project supported by funding from the Australian Government Department of Climate Change under its ‘Climate Change Adaptation Skills for Professionals Program’. The development of this publication has been supported by the contribution of non-salary on-costs and administrative support by the Griffith University Urban Research Program, under the supervision of Professor Brendan Gleeson, and the Australian National University Fenner School of Environment and Society and Engineering Department, under the supervision of Professor Stephen Dovers.

Chief Investigator and Project Manager: Karlson ‘Charlie’ Hargroves, Research Fellow, Griffith University.

Principle Researchers: Dr Michael Smith, Research Fellow, ANU; Cheryl Desha, Research Intensive Lecturer, Griffith University, and Peter Stasinopoulos, Research Officer Griffith University.

Research Support: Angie Reeves,Research Officer Griffith University, and Stacey Hargroves, Professional Editor, Griffith University.

Peer Review

This chapter was peer reviewed by Victoria Hart, Facilitator and Program Director, Sustainability Victoria;Anntonette Joseph, Director,Green Precincts Fund, Water Efficiency Opportunities,CommonwealthDepartment of Environment, Water, Heritage and The Arts.

Review for this program was also received from: Alex Fearnside, Leader of the Sustainability Team, Melbourne City Council; Alison Scotland, Sydney Water Corporation; Anna MacKenzie, ACT representative, Australian Association of Environmental Education and Deputy Principal Campbell Primary School;Anntonette Joseph, Director, Urban Water Efficiency Initiatives, Commonwealth Department of Environment, Water, Heritage and The Arts; Barry Coker and Jeffrey Briggs, St Andrews Hospital, Brisbane; Dr Barry Newell, ANU Fenner School of Environment and Society, Facilitator of ANU Fenner School of Environment and Society’s Climate and Water Integration Group; Caleb Furner, Sydney Water Corporation; Carl Binns, Sydney Water Corporation; Claire Hammond, Sydney Water Corporation; Cheryl Davis, International Water Association; David Dumaresq, ANU Fenner School for Environment and Society, Senior Lecturer Human Ecology, Agro-ecology, and Sustainable Systems; Dennis Lee, Sydney Water Corporation; Glenn MacMillan, Genesis Now Pty Ltd; Jill Grant, Director Sustainable Development, Commonwealth Department of Resources, Energy and Tourism;Karen Jacobson, Commonwealth Department of Resources, Energy and Tourism; Kevin Moon, Institute of Hospital Engineering Australia; Kieran Coupe, Manager, MeterMate, Water and Energy Managers; Nick Edgerton, AMP Capital Sustainable Share Fund (formerly the Institute for Sustainable Futures, University of Technology Sydney, Australia); Para K Parameshwaran, Sydney Water Corporation; Adj. Prof Paul Perkins, Australian National University, Chair, Environment Industry Action Agenda and Barton Group; Dr Marguerite Renouf, Director UNEP Working Group for Cleaner Production, University of Queensland; Phil Smith, President of the Australian Association of Environmental Education; Rob McKenna, Energy Saving Specialist, Water & Energy Programs, NSW Department of Environment and Climate Change; Sally Armstrong, Sydney Water Corporation; Stan Scahill, The Institution of Engineers Australia (Biomedical Engineering College); Stephen Fahey, Environment Officer (Energy & Water), ANU Green; Victoria Hart, Facilitator and Program Director, Sustainability Victoria; and Vivian Filling, Australia Industry Group.

Enquires should be directed to:Karlson ‘Charlie’ Hargroves (

Adapting To Changes in Water Availability - Industrial & Commercial Sectors

Lecture 2.4: Built EnvironmentSector – Water Savings in Retail, Commercial and Office Buildings

Educational Aim

This lecture provides an overview of the major areas of water usage and potential for water savings in retail, commercial and office buildings, highlighting supporting key resources. While there are many resources explaining how to achieve water savings in the home comparatively little assistance has been provided to other building types such as retail, office and commercial spaces, and this lecture focuses here.

Key Learning Points

  1. Commercial, retail and office buildings are large consumers of water. For example, according to the Department of Environment, Water Resources, Heritage and the Arts, ‘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’.[1] Further, office water use can account for 10 percent of capital city water consumption.[2]
  2. However, in the past water prices have been so low that many commercial, office and retail buildings have not invested in water saving measures. This hasresulted in the current situation where many water saving options exist in these parts of the built environment sector with payback periods of less than two years.[3]With the forecast rise in water prices over the coming years, a range of often-simple measures can realise substantial cost savings,[4] Further, water savingsin commercial andoffice buildings can also reduce associated sewage, chemical, energy and trade waste costs, in addition to attractingenvironmentally minded tenants.
  3. A key area to achievewater savings in commercial building and office space is to address leaks.Identifying and repairing water leaks is often the most cost effective of all water management measures, and is best done early on in order to ensure that any measure of baseline water consumption is accurate. According to Sydney Water, a building is likely to have water leaks if it has a cooling tower and consumes more than 1 kL/m2/year, or if it doesn’t have a cooling tower and consumes more than 0.65 kL/m2/year.[5] The main exception to these threshold values is large retail malls/shopping centres, which usually consume more water per unit floor area than other commercial buildings. A shopping centre is likely to have water leaks if it consumes more than 1.70 kL/m2/year. Locating where water leaks are occurring can be done by using sub-meters to measure and monitor water use around key component junctions in the building’s plumbing.
  4. Once leaks have been identified and addressed, awater audit is an essential tool in developing a strategic plan for reducing water consumption.Reviewing data frommain water meters and sub-water meters will provide a measure of the building’s baseline consumption. Subsequent water efficiency measures can then be compared against this baseline and, ultimately, the building can be benchmarked against other buildings in the same industry or against some rating system,for example ‘National Australian Built Environment Rating System’(NABERS).[6]The priority building components to sub-meter are the large water consumers that are typically the least water efficient, including the cold water supply, hot water supply, amenities, cooling towers, outdoor areas and water features, retail shops and sewer discharge.[7]Following the water audit and assessment of priorities, water saving measures can then be strategically undertaken – by the landlord, tenant or owner.

Key areas for water saving are highlighted in the following learning points, and example buildings are highlighted in the Brief Background Information;

  1. Installing Efficient Amenities as Part of a Building Retrofit: Toilets, taps and urinals are all common sources of water waste and maintenance costs in commercial buildings. There are significant opportunities to reduce water consumption in all these areas, which include installing low flow taps (70 percent less water),[8] 6/3 litre dual flush toilet systems (67 percent less water)[9] and waterless urinals.[10] For example, CB Richard Ellis upgraded its amenities in one of its managed properties on Pitt Street, Sydney, resulting in water savings of over 60 percent to 40 kL/day (0.6 kL/m2/year), electricity savings of over 5 percent due to asmaller demand to pump water and cost savings of over AUD$4,000 per month.[11]
  2. Replacing Evaporative Cooling Systems with Wet/Dry Hybrid Cooling Systems: One of the biggest areas of water usage in the building industry is in cooling towers. This can account for at least 15 to 30 per cent of a building’s water use. The main alternatives to water cooling systems are dry cooling systems, which do not use any water but use much more energy. There are also some opportunities to reduce water through smaller efficiency measures.[12]However, on the market now are wet/dry hybridcooling systems, developed by Muller Industries Australia and BAC, which enable a 4-5 fold reduction in water usage while consuming just 5percent more energy than water cooled systems.[13]
  3. Rainwater Harvesting: Demand, and hence cost, for mains water supply can be reduced by capturing rain water from rooftops then storing it in tanks for use throughout the building. Water for drinking, showers and hand basins are required to be tertiary treated, which usually includes being filtered, and disinfected with UV filters and perhaps chemicals. Water for toilet flushing, irrigation, vehicle washing and other approved uses may not require treatment.[14](This lecture provides several examples of organisations benefiting from rain water harvesting systems in their commercial buildings.)
  4. Grey Water Reuse: Demand for mains water supply can be further reduced by capturing grey water from basins, sinks and showers, as well as capturing used water from fire system tests, then settling it in basement tanks for use throughout the building. Also water can be extracted from municipal sewerage lines running under buildings, such as the Melbourne City Council building CH2, that are 90 – 95 per cent water. To use such water in toilets, urinals and irrigation it needs to be tertiary treated onsite, which usually includes being filtered with mechanical and biological filters, and disinfected with UV filters and chemicals.[15]
  5. Proactive Preventative Maintenance Program: Preventative maintenance can also lead to water and cost savings, with such a program involving preventative checks, component repairs, and component replacements, throughout the entire building system every 3-6 months, rather than repairing components once they become a problem, which is currently typical practise.Establishing a preventative maintenance program reduces the occurrence of leaks, blockages and component failure, and can enable a building to service its occupants more reliably and with lower maintenance and repair costs overall.
  6. Tenant Education and Behaviour: When changes are made to reduce the water consumption of buildings, or to institute water recycling and reuse, it is important that tenants and staff are aware of the changes, and how they may assist in their success. It is also important to ensure buy-in and support from tenants as it is often the tenant that reportsa leak and if not empowered to do so this can be left until the problem affects performance before reporting. In some cases, occupants have been known to remove badly installed, or poorly performing,aerators from taps because it reduced the utility of the tap, rather than report it. Further, there is a need to provide occupants and those working in the building with the appropriate information and briefings related to the water management plan. In particular cleaners and caterers need to be aware of issues related to floor cleaning (for example broom, mop and bucket over spraying, the cleaning of waterless urinals) and using spray nozzles for cleaning dishes.

Brief Background Information

The following text discusses options forwater savings in retail, commercial,and office buildings through addressing sources of leakage, using water more efficiently in amenities and saving water in cooling towers, all of which account for roughly 95 percent of water usage as shown in Figure 2.4.1. Before considering how to do this, it is important to review some of the issues and barriers to change in multi-tenanted buildings.

Figure 2.4.1Typical CommercialBuilding Office Water Usage Patterns

Source: Based on DEWHA, 2007[16] (Redrawn by TNEP, by R. Dennis)

The Szencorp building[17] and the City of Melbourne’s CH2 office building[18] are just two of many green buildingsthat have been developedin recent years, financed by governments, institutions and corporations. However, while there is a strong movement to greener practice for owner-occupied buildings, there is relatively little adoption of green design and water efficiency practices in multi-tenant office and retail spaces. The reason for this low adoption, according to Rocky Mountain Institute’s Built Environment Team,[19] is that typical leases create split incentives among owners and tenants – owners don’t pay the water bill and so have little incentive to improve water efficiency and tenants don’t control the buildings’ infrastructure so cannot set-up metering systems to monitor usage and act on the findings.Nonetheless, there is still a persuasive argument for multi-tenanted buildings to adopting these water saving measures, as discussed in a number of Sydney Water publications (see specific references below). This includes the following:

-Cost Savings:The true cost of water and wastewater processing and disposal is currently underestimated, and is rising.For example, in Australia water costs around AUD$1.34/kL, wastewater costs AUD$1.30/kL, trade waste process charge costs at least AUD$0.57/kL and hot water costs AUD$3.13/kL for energy.[20]Fixing leaks and improving the efficiency of amenities are some of the most cost effective ways to reduce water consumption in addition to savings from reducing the demand for heating and cooling by air-conditioning systems (which conventionally use water in cooling towers to provide air conditioning for buildings). Strategies for reducing the demand for active heating and cooling include:[21]

  • Avoiding undesirable heat generation inside the building:using energy efficient lamps, office equipment and other appliances, which emit less heat in the workplace.
  • Favouring passive heating and cooling:orienting the building, incorporating ventilation channels, and situating overhangs and windows to optimise natural ventilation, solar gain and natural daylighting.
  • Increasing the efficiency of the air-conditioning system:installing control systems that switch on and off certain outlet zones as required; favouring long, straight,smooth duct sections; andusing and maintaining right-sized,energy efficient motors, fans,HVAC units and other components.

-Attracting the Best Tenants:Many government departments and large corporations now have environmental policies that require them to reduce the environmental impact of their operations and this is leading to a preference for office space that offers optimised water and energy services. These include requirements for owners of office and retail space to commit to green leases that require a range of actions to reduce mains water and energy demand. As government tenants account for up to 30 per cent of the commercial office market in major cities such as Sydney,.[22]this forms a significant driver for owners, especially as governments are known for taking long leases and paying rent on time.

-Marketing:Most people are aware of the importance of saving water so it makes sense to let tenants, employees and visitors know what is being undertaken to save water and how they can help. As the environment it is an increasingly sensitive issue this type of commitment can boost staff morale, allowing them to feel proud to work in the building, and have a positive influence on the perceptions of building developers, owners and managing agents. Green building rating schemes now exist and are increasingly being used, such as NABERS and GreenStar in Australia, and property owners are using these to provide product differentiation in the marketplace. For example, Stockland Property Group’s headquarters in Sydney was one of the first large commercial properties to get a NABERS rating for its entire portfolio.[23]