The key issues to the development of a performance-based building energy code for Hong Kong

The Hong Kong Government is intending to develop a performance-based building energy code based on the total energy budget approach to provide an alternative compliance route to the five existing building energy codes. This is an essential add-on to the codes if the codes are to be made legislative requirements. In the paper, the key issues that need to be addressed in the development of a performance-based building energy code for Hong Kong are identified and discussed. First, the new performance-based code should be limited in application to new buildings of those types that are subject to the control of all the existing codes. Second, the items put under the control of the existing codes should be categorised into basic, prescriptive and performance-based requirements. For the performance-based requirements, rather than a set of explicitly defined compliance criteria, the methods for determining performance that would be equivalent to the prescriptive requirements should be defined. This applies also to the total energy budget method that is meant to provide the greatest flexibility for demonstrating compliance. Furthermore, an intermediate level of performance-based compliance path should be introduced between the prescriptive requirements and the total energy budget method. Third, while the development of simplified calculation methods would be essential, the methods and tools for assessment should include the use of building energy simulation software to provide the required flexibility to deal with varied situations. Fourth, standardised building occupation conditions and patterns should be defined as the basis for determining realistic trade-offs.