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 purpose of this research is to study the Labor Productivity Rating of workers and the quality of work that has been done by studying dry process bored pile which is 0.50 x 24.00 meters in diameter 170 piles at the construction of a building in Bangkok. Researchers conducted a cycle closed system of dry process bored pile into the four activities are: (1) the movement of the drill into the bored pile position (2) the casing procedure (3) the reinforcement procedure and (4) the pouring of the concrete and casing removal. The results showed that yield of dry process bored pile have an averaged Labor Productivity Rating about 275.31 minutes/pile The Quality jf the research has been divided into two cases: (1) quality of bored pile by testing the integrity of the pile by the Seismic Integrity Testing method in the standards of ASTM o 5882-00 found that 95.30 percent of the piles were in perfect condition and a slightly defective of 4.70 percent and (2) the position of bored pile found to be in accordance with allowable error of 100 percent. The results of the study can be utilized in work planning estimating cost of Labor and monitoring and tracking the progress of the work.

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.