Building energy efficiency assessments in Hong Kong and the way forward

The Hong Kong Government has issued five codes of practice on energy efficiency of buildings, including one on overall thermal transfer value (OTTV) of buildings and four on major services installations in buildings. Compliance with the OTTV code is now a legal requirement to new commercial and hotel buildings. Although the other four codes were also intended for mandatory implementation, they are being implemented under the voluntary Hong Kong Energy Efficiency Registration Scheme for Buildings (HKEERSB). The Hong Kong Building Environmental Assessment Method (HK-BEAM) is a private sector voluntary scheme, which assesses a wide range of environmental issues, including energy efficiency. The scope, methods and criteria of building energy performance assessment in the two schemes are largely different. Yet, the performance-based assessment method and the philosophy adopted for setting the zero credit levels in HK-BEAM make it a suitable alternative compliance route to the codes. The need for, and the benefits of, having such an alternative route to prescriptive controls in the codes are discussed and exemplified through a comparison of the assessment results of a building that has undergone both the HKEERSB and the HK-BEAM assessments. The study revealed that the minimum performance level that would pass the lighting and air-conditioning codes would lead to zero credits under the HK-BEAM assessment, which is a reflection that buildings obtaining some credits would have an energy performance standard above the minimum set by the codes, and that it would be important to allow trade-offs amongst the assessed issues in the codes.Department of Building Services Engineerin