1. Associate Professor, Dept. of Building and Real Estate, The Hong Kong Polytechnic Univ., Hung Hom, Hong Kong (corresponding author). E-mail: bscmhui@polyu.edu.hk
2. Professor, Dept. of Building and Real Estate, The Hong Kong Polytechnic Univ., Hung Hom, Hong Kong. E-mail: bsbill@polyu.edu.hk
3. Research Assistant, Dept. of Building and Real Estate, The Hong Kong Polytechnic Univ., Hung Hom, Hong Kong. E-mail: gordonkcwong@yahoo.com