1. Ph.D. Fellowship Student, Dept. of Building and Real Estate, Hong Kong Polytechnic Univ., 181 Chatham Rd. South, Hung Hom, Kowloon, Hong Kong (corresponding author).
2. Chair Professor and Head, Dept. of Building and Real Estate, Hong Kong Polytechnic Univ., 181 Chatham Rd. South, Hung Hom, Kowloon, Hong Kong.