Climate change has become a pressing concern around the world. In order to combat climate change, concerted efforts are crucial to reducing greenhouse gas emission to limit global warming in the 21st century to below 2ºC, preferably below 1.5ºC, compared to pre-industrial levels. In Hong Kong, the Government is committed to achieving carbon neutrality before 2050. As buildings account for 90% of the electricity used in Hong Kong and generate over 60% of Hong Kong’s carbon emissions, “energy saving and green building initiatives” is one of the main decarbonisation strategies in Hong Kong.