sia has, in general, taken little interest in matters of environmental sustainability; neither has the region directed much attention to energy management. However, recent increased instability in the Middle East has reminded the world that a real possibility exists of a repetition of the global oil crisis of the 1970s. The spectre of serious energy-cost hikes has reawakened concern about future energy consumption and availability.

In 1994, the Asia-Pacific Economic Cooperation (APEC)commissioned a study for the development of an energy-benchmark system for Asia-Pacific member nations, using a database involving a number of buildings. However, this database proved next to worthless because the targeted building designers and owners paid little attention to it, seeing it as lacking relevance for them.

Perhaps peer benchmarking would be a more effective way to apply pressure and accelerate the pace of energy management. If building owners could be shown that their buildings carry a higher energy price tag than their competitors' down the street, they are more likely to take corrective measures.

A research team at the Centre for Total Building Performance (CTBP), a joint venture of the National University of Singapore and the Building and Construction Authority of Singapore (BCA), has conducted a study to look into ways to implement a plan for Singapore. The researchers collected energy consumption data for representative office buildings on the island by selecting 104 buildings with different gross floor areas, heights and ages, in accordance with the Urban Redevelopment Authority's classification of the term "office building."

The investigators subjected the gathered data to tests to ensure an accurate and representative sample reflecting the overall behaviour of an entire cohort of office buildings. Both the data sets for total building energy consumption (Figure 1) and the landlord's portion of energy consumption (Figure 2) achieved a high level of accuracy.

The energy performance of a building can be assessed using an efficiency index, such that regardless of building's size, height or age, a single parameter of energy efficiency suffices to differentiate energy-efficient buildings from the more wasteful ones. Test results showed that energy-efficiency indices of buildings with various gross floor areas were highly correlated.

Building owners can determine the energy-performance-efficiency level of their buildings and compare it to the entire group of office buildings (Figure 3) with the help of a chart available on an interactive website put up by the research team (www.bdg.nus.edu.sg/buildingenergy). The site contains results for office buildings, covering both total energy efficiency and landlord energy efficiency. Linked to the Government Directory, it offers Web-based energy-performance benchmarking.

This information base is useful for a number of reasons:

• Building owners and managers can easily obtain quick, accurate and objective information, free of any commercial interest, on the energy performance of their buildings.
• Building managers can target building improvement and, with a good estimate of the amount of savings achievable, move up the percentile curve.
• If the building-performance standard falls, there will be more pressure to improve.
• Energy-service suppliers find the information valuable as it provides an independent resource supporting their efforts to convince building management to embark on energy performance improvement schemes.

The office building benchmarking information system has made a significant contribution to, and has had a major impact on the industry and can therefore be considered a success. Furthermore, the study and its results are unique, and the database represents the first in Asia. Among developed nations, even though databases are commonplace, properly tested and Web-based benchmarking is not available. In addition, databases developed with a reliance on building information obtained from temperate climates have little applicability for tropical Singapore and its neighbours.

The Energy Efficiency and Conservation Network, via the Association of Southeast Asian Nations (ASEAN) Centre for Energy, has launched a project to develop a similar benchmarking system for various ASEAN members. Associate Professor Lee Siew Eang, the coordinator for the ASEAN-wide project, also serves as the chair of the Board of Judges for the ASEAN Energy Efficient Building Best Practices Awards.

Although this study gives a holistic, nationwide benchmarking curve for Singapore, the same methodology has application to other cities in the region. Local energy conservationists can conduct studies at their city's level, using the methodology established by the research team; benchmarking countrywide would be meaningless owing to the significant gap in economic development between cities and surrounding areas.

The project team is now looking into profiling energy consumption characteristics of buildings belonging to different classes of energy performance, giving valuable information to designers as well as building owners. First, the team examines the specific functions of buildings. For example, data centres, major facilities and tenants of many high-tech buildings consume a lot of energy because computing equipment and storage facilities need to be kept cool on a 24-hour basis.

Once the regional study on benchmarking inter-city energy use is complete, the team will create a larger information base for the whole region.

For more information contact Assoc Prof Lee Siew Eang at bdgleese@nus.edu.sg.