The data came from secondary sources such as from EPRC limited and governmental publications, which is a usual practice. The information of unit orientation was also collected from Centaline and Midland Realty web sites. In the study, the transaction records of all selected green and non-green buildings in the period of 1 July 2003 and 1 September 2008 were obtained from the EPRC. This particular transaction period was specifically chosen in order to avoid the SARS outbreak in 2003 and global financial crisis in 2008. The data of transaction price, building age, floor level, floor area, orientation and view were obtained from the EPRC. The information of the HK-BEAM certification and HK-GBC awards was obtained from their web sites. As the properties were transacted in different times, the price index issued the Rating and Valuation Department was used to deflate the property price.