ABSTRACT

The construction of Phase 1 of Airlangga Edupreneur Center at Campus B in Surabaya, specifically Guest House 1 and 2, involves significant structural costs, making it vulnerable to overruns from construction waste. This study aims to identify materials that could become dominant sources of waste, estimate their financial impact, and formulate Green Building mitigation strategies. The study utilized secondary data, specifically the Cost Estimate (RAB), Structural Drawings, and S-curve, analyzed via the ABC/Pareto Method to identify critical materials; theoretical waste volumes were estimated using standard literature coefficients (SNI AHSP PUPR) as a substitute in the absence of direct field observations. Results show three critical materials: rebar (39.44%), pile foundations (19.22%), and formwork (18.98%), collectively account for 77.65% of total structural costs for both buildings. The estimated financial loss from the theoretical waste of these materials was Rp 621,741,434, which remained well below the 10% threshold across all comparison bases. However, formwork was identified as the critical point with the highest waste rate (9.09%), which was heavily concentrated between the 8th and 19th weeks, based on S-curve integration. Formulated mitigation strategies include applying Modular Design to formwork, developing a Waste Management Plan, and reusing leftover materials in accordance with the GBCI’s Material Resources and Cycle (MRC) criteria. Simulations indicate that these steps could generate cost savings of up to Rp 167,906,864, or 68% of the existing formwork loss. This study demonstrates that a literature-based approach using secondary data efficiently produces measurable estimates of over-budget risk, providing an effective basis for crucial mitigation decisions during the pre-construction phase.