Effects of Site Layout and Congestion on Masonry Works Labor Productivity

Construction labor productivity significantly influences project cost, schedule performance, and overall project success. However, the effects of site layout inefficiencies and workspace congestion on labor performance remain inadequately quantified, particularly in developing-country construction settings. This study examines the relationship between site layout, congestion, and labor productivity in a commercial warehouse development project in Old Sauyo, Quezon City, Philippines, focusing on concrete works, masonry works, and wall plastering activities. The study contributes empirical evidence on the productivity implications of construction site layout and presents a simulation-based framework for evaluating spatial planning strategies.

A mixed-method case study approach was employed using site observations, time tracking, workflow monitoring, and site mapping during active construction operations. Productivity was assessed through physical site observation and recording of task duration, hourly work output, worker density, and time losses associated with congestion and physical obstructions.

Lean Construction principles and Human Factors Theory provided the theoretical basis for evaluating the influence of spatial organization on worker efficiency. Furthermore, Discrete-Event Simulation (DES) was utilized to model alternative site configurations and quantify the impact of congestion on workflow performance.

Results indicate that poorly planned material storage, narrow access routes, overlapping work zones, and limited workspace significantly reduce labor productivity by increasing non-value-adding activities and workflow interruptions.  Congestion impact ranged only from 1.19% to 3.54% across different trades, however, compared to National productivity benchmarks, masonry and plastering showed significant productivity differences of 76.59% and 57.89%, respectively.

DES outcomes demonstrate a marked decline in productivity under high-congestion scenarios and confirm the benefits of optimized spatial arrangements. The findings provide practical guidance for project managers and site engineers in designing more efficient, safer, and productivity-oriented construction environments.