B. N. Liyanage1, B.A.K.S. Perera2 , D.M.G.A.N.M. Sumanarathna3 and L.D.I.P. Seneviratne4  
1Quantity Surveyor, P&C Professional Quantity Surveyors & Cost Consultants (Pvt) Ltd, Gampaha, Sri Lanka, alnishani@gmail.com 2Senior Lecturer, Department of Building Economics, University of Moratuwa, Sri Lanka, pererabaks@gmail.com 3 Lecturer, Department of Building Economics, University of Moratuwa, Sri Lanka, nipuni.sumanarathna@gmail.com  4Senior Lecturer, Department of Building Economics, University of Moratuwa, Sri Lanka, isenevi@gmail.com