The purpose of this research is to study the effect of a safety system provided for wall tile external building activity on productivity. The safety system composed of (1) stable scaffolding system (2) providing clean and not slip walkways on the scaffold (3) installation of handrails not less than 0.90 meters in height along sides of the scaffold (4) installing safety nets around outside perimeters of the scaffolding (5) indicating working area (6) installing stairs (7) providing protection for people who works below (8) providing tools and equipments for transporting material which are safe and ready for using and (9) providing personal protective equipment for workers. Cost of the safety system is 79318 baht for a wall tile area of 385 m2 or approximately 206 baht/m2. Productivity rates for prior and after the used of safety system are 1.91 and 1.85 m2/person/day respectively. The productivity declines for approximately 3 %. In addition our study found an impact of work is a height of Building the wall tile external productivity could decrease for 6 %.

The purpose of this research is to study the construction safety system for working at height. The safety system for working at height in this research is predetermined by department of labour protection and welfare and safety and health at work promotion association (Thailand). The safety system composed of (1) safety policy (2) safety organization (3) prevention measure (4) risk analysis (5) training (6) safety inspection (7) accident report and (8) emergency planning. Since they had been used construction safety system for working at height in construction site. They have seen different number reduced from accident on site project. However the cost of construction project would have increases.For example building construction site project would taking more time to finished their project. Such as project A have costs increase 281385 baht Project B have costs increase 263648 baht and Project C have costs increase more 285413 bahtRespectively.

The purpose of this research is to study the construction safety system for working at height. The safety system for working at height in this research is predetermined by department of labour protection and welfare and safety and health at work promotion association (Thailand). The safety system composed of (1) safety policy (2) safety organization (3) prevention measure (4) risk analysis (5) training (6) safety inspection (7) accident report and (8) emergency planning.

The purpose of this research is to study the effect of a safety system provided for external wall plastering activity on productivity by studying a construction of commercial buildings. The safety system composed of (1) stable scaffolding system (2) providing clean and not slip walkways on the scaffold (3) installation of handrails not less than 0.90 meters in height along sides of the scaffold (4) installing safety nets around outside perimeters of the scaffolding (5) indicating working area (6) installing stairs (7) providing protection for people who works below (8) providing tools and equipments for transporting material which are safe and ready for using and (9) providing personal protective equipment for workers. Cost of the safety system is 79665 baht for a wall area of 1510 m2 or approximately 53 baht/m2. The prevention cost is quite high because it is an initial investment cost. However contractors could repeat theirs used on future projects. Productivity rates for prior and after the used of safety system are 1.16 and 1.13 m2/person/hr respectively. The productivity declines for approximately 3%. In addition our study found an impact of predecessor activity which is a brick laying activity. If brick walls are not well aligned and plumbed the working time for wall plastering could take longer for 8%. Meanwhile the wall plastering productivity could decrease for 11% and labor cost could increase for 12%.

The goal of this study is to study the cost of safety system in building construction by studying multipurpose building with durable goods project. The cost of safety system in building construction is divided into two categories are the safety measure cost and the safety program cost in construction. From the study it is found out that the value of safety measure cost is approximately 1.85 % of a project cost and the value of safety program cost is approximately 0.98 % of a project cost. To sum up the cost of safety system in building construction is approximately 2.83 % of a project cost .Moreover the study found out that the safety measure cost is higher than the safety program cost about 1.88 as much. From the data of this study it can be used as the guideline in estimating the cost of safety system in building construction for the future project.