Clean Energy and Smart Technology
Vol. 5 No. 1 (2026): October

COST AND ON-SITE DURATION COMPARISON OF CONVENTIONAL AND PRECAST FLOOR SLAB METHODS: A TWO-STORY BOARDING HOUSE CASE STUDY IN YOGYAKARTA

Yohanis Kresna Nahak (institut teknologi nasional yogyakarta)
Rizal Maulana (institut teknologi nasional yogyakarta)
Oggi Heicqal Ardian (institut teknologi nasional yogyakarta)
Sely Novita Sari (Institut Teknologi Nasional Yogyakarta)



Article Info

Publish Date
31 Oct 2026

Abstract

Floor slab construction strongly affects both the cost and the on-site duration of low-rise buildings, yet transparent project-level comparisons for small boarding houses remain scarce. This study compares the direct cost and on-site construction duration of conventional cast-in-place and precast floor slab methods for the 50.36 m² second-floor slab of a two-story type-135 boarding house in Pugeran, Yogyakarta. A quantitative comparative case study was applied using project drawings, an itemized quantity take-off, the Indonesian Unit Price Analysis (AHSP), documented local price bases, a supplier quotation, and labor-based duration calculations. The conventional alternative cost IDR 35,746,962.53 and the supplier-inclusive precast alternative IDR 30,216,000.00, a project-specific saving of IDR 5,530,962.53 (15.47%), while the calculated on-site duration fell from 11 days to 2 days, a reduction of 9 days (81.82%). A sensitivity analysis shows that the cost advantage reverses once the precast price rises by about 18%, identifying the condition under which the conventional method becomes cheaper. The reported savings apply only to the prices, crew composition, and work scope adopted in this case study; they exclude factory lead time and curing, and they do not constitute structural verification of the precast system.

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Journal Info

Abbrev

cest

Publisher

Subject

Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Mechanical Engineering

Description

The Clean Energy and Smart Technology (CEST) journal aims to provide a platform for researchers, academicians, and professionals to publish high-quality articles that explore innovative ideas and solutions in the field of energy and technology. It focuses on fostering interdisciplinary research and ...