# Updating Financial Contingency in Execution of Typologically Diverse Construction Projects
## 4 Summary and Discussion  
The selection of the research sample resulted from the specificity of measuring the implementation parameters and processing the research data, which made it impossible to freely choose construction projects. The presence of these projects in the research sample is the result of commercially obtained orders. The collected data formed a closed set, including 41 construction projects, which consisted of a total of 547 measurements. The typological division into residential buildings, office buildings, hotels, shopping centres and logistics centres, due to their affiliation to specific typological groups, resulted in a differentiated number of objects, and thus the number of measurements, in individual groups. The consequence of this division, despite random selection, was the loss of full representativeness in the research sample due to its small size. Other requirements, such as population structure mapping, random selection and no bias of selection, ensured that the sample maintained high data quality. The resulting quality of the data is acceptable and sufficient to support the conduct and conclusion. Analysis of the variability of the CPI cost overrun rate for a variety of construction projects was performed using a box plot tool, both within separate groups and between individual projects. This is evidenced by the shape of the box charts, characterised by high variability, and their positioning relative to the horizontal axis, indicating the magnitude of exceedances. The benchmark for the developed graphs of cost overspending represented by the CPI is the financial contingency, considered as an acceptable cost overrun. The size of this reserve is set by the banks and is 3% of the cost of the entire investment. Therefore, in this analysis, it should be interpreted as a range of excess values [0.97, 1]. Table 2 shows the aggregate results obtained from the analysis of the final CPI values in each group of facilities, indicating the extreme values of deviations and the values obtained in the first and third quartiles. In the four groups of projects studied, residential buildings (M), office buildings (O), hotel buildings (H) and shopping centres (G), there were cases in which cost overruns were greater than the financial contingency set by the banks. The exception is the group of logistics centres (G), where the total cost of projects was maintained at an overrun of less than 3%. A high irregularity in the cost overspending of individual investments was observed in all the groups studied and is evident in the different shape of the graphs representing them. This is evidenced by the height of the boxes, which represent CPI values just from the Q1-Q3 range. Even in cases of investments where the cost was kept in financial contingency, a varying spread of CPI values is observed. This fact leaves uncertainty in forecasting the cumulative cost of investments. Also, when analyzing the final values of the indicator, a wide variation in the width of the value ranges was observed in each group of projects, resulting in a variable size of deviations from the planned cost and the financial contingency. Given the magnitude of the excess of the financial contingency, occurring in the group of residential buildings (M), amounting to 0.96, and the presence of outliers, it is recommended to increase the financial contingency to 5% of the investment cost. This will allow financially secure completion of the project, taking into account the possibility of cost overruns, falling within the updated financial contingency. Increasing the financial contingency to the level of 5% of the project value is also recommended for the group of office buildings (O). Despite exceeding the financial contingency and obtaining a CPI value of 0.95 (5% deviation from the planned cost), it was assumed that in the analyzed group of projects, given the width of the range and the absence of CPI outliers, major overspending would not occur.