Eygen Rapendes, Buyung Mantap
The selection of a structural system is an important factor in determining the success of construction projects, particularly in terms of cost efficiency and implementation time. Reinforced concrete remains a widely used conventional method due to its high structural durability, while lightweight steel has emerged as an alternative construction system with practical characteristics and faster installation processes. This study aims to compare the construction costs and implementation time between reinforced concrete and lightweight steel systems for a two-story residential building in Bengkulu. The research employed an empirical comparative study through identical building modeling, work volume calculations, unit price analysis based on SNI standards, and construction duration estimation. The results indicate that lightweight steel provides lower construction costs and shorter implementation time compared with reinforced concrete. Lightweight steel is recommended for projects prioritizing time and resource efficiency, while reinforced concrete remains a suitable option for buildings requiring higher structural durability.