Comparison of the Performance of “Unit Area Cost Method” (UACM) and “Unit Price Method” (UPM) Used in Estimating the Costs of the Reinforced Concrete Multi-Storey Housing Buildings

Unit Price Method (UPM) and Unit Area Cost Method (UACM) are widely used in the cost of reinforced concrete multi-storey housing buildings. In this study, it is aimed to determine the cost estimation method with high performance (its use will provide an advantage to the estimator over the other) by comparing the cost estimates in the modeling by making “Regression Analysis” (RA), with the data of such struction. In the literature review, studies of equivalent and different structures were evaluated. In modeling; Number of rooms, floor area, total area, number of floors, floor height, facade area, facade void area, Bathroom/wc areas, balcony areas, building height are parameters. UPM and UACM based costs which were created with the data of 2020 of 41 similar structures (38 for modelling, 3 for tests) were used as independent variables, and cost models were created with linear regression analysis. The results were randomly selected and compared with test groups that were not used in these models, and the error rates and performances of the methods were tested. According to the comparison, in the UACM analysis, there was a high R2 value in 6 data and a low error rate in 8 predictions; In the UPM analysis, it was determined that an equally high R2 value and a low error rate occured in 7 predictions. As a result, UACM reached a better performance in finding the estimated cost; It has been observed that using it in cost estimation gives better results. However, even if UACM performed better, the difference in error rates is very low, at 2.7%.