Volume 19, No. 04, Month DECEMBER, Year 2019, Pages 213 - 232

Effects of sorting schemes on the most cost-effective number of energy conservation measures

Thosapon Katejanekarn, Narong Promsorn

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When several energy conservation measures (ECMs) are to be implemented to earn points from a building energy rating system, it is essential to decide upon the order of their implementation. To answer the question about what sorting scheme should be employed, this study aimed to investigate the effects of different sorting schemes on the most cost-effective point and the corresponding number of ECMs to be implemented. Six sorting schemes comprising energy saving, investment, points, payback period (PB), net present value (NPV), and internal rate of return (IRR) were applied to 10 common ECMs that were to be implemented on four sample buildings. The chosen rating systems were ASHRAE’s Building EQ, and the energy topic in LEED v4, BEAM Plus v1.2, and TREES v1.1. The study’s findings showed that each sorting scheme led to literally the same cost-effective point. If the ECMs were sorted by energy saving or points, a significantly lower number of ECMs would be required. However, this needed a trade-off with high investment in ECMs from the beginning. Conversely, the other four sorting schemes required a gradual increase in investment in ECMs, as well as almost all, or all, ECMs needing to be implemented. Moreover, the more stringent rating systems, such as Building EQ and LEED, tended to have a higher investment cost in ECMs per unit area per %credit. The implementation of expensive ECMs was found to be more economic in larger buildings.


building energy rating systems, energy conservation measures (ECMs), most cost-effective point, sorting scheme.


Published by : Asian Institute of Technology
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