## 4 Methods
### The Classification of Defects  
Based on the analysis of the literature, as well as on the results of the research conducted during the warranty period, the authors propose a three-stage qualification of defects: low, medium, and high significance. The division into these groups corresponds to many publications [3]. In this paper, the following definitions are adopted:  
* Defects of high significance--defects causing the appearance of a fault that prevents proper operation of the premises, which may cause a threat to the health or life of people using the property. Removal of very important defects usually requires the elimination of the causes and their effects. Repair works are associated with large financial and material outlays and are time-consuming. Examples of very important defects include flooding of the property, cracking of a structural element, short-circuit of the electrical system, causing fire, or leakage of the roof sheathing.
* Significant defects--faults causing limitations in the proper operation of the premises. This formulation identifies a number of defects that reduce the possibility of unrestricted use.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Building**} & \multirow{2}{*}{**Number of Defects**} & \multicolumn{2}{c}{**Valid**} & \multicolumn{2}{c}{**Unfounded**} \\ \cline{3-6}  & & **No.** & **\%** & **No.** & **\%** \\ \hline A & 153 & 96 & 62.75 & 57 & 37.25 \\ B & 135 & 79 & 58.51 & 56 & 41.48 \\ C & 46 & 27 & 58.70 & 19 & 41.30 \\ Total & 334 & 202 & 60.48 & 132 & 39.52 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Defect statistics after 12 months from acceptance.  
Figure 2: Percentage of valid claims under warranty, presented cumulatively.  
However, they do not force the cessation of use because they do not constitute a direct threat to the health and life of the users. Due to the large dispersion of the types of these defects, it is not possible to clearly determine the degree of technical and technological complexity of their removal. Examples include the following: intercom failure, decaying tiles on the balcony, unsealing of window and balcony joinery, or slow main door locks.
* Defects of low significance--a minor defect that does not hinder the operation of the premises. This term is used by the authors to describe a defect that has a visual or cosmetic effect, which does not influence the functional properties of the premises. The removal of these defects does not generate the necessity of using any advanced technology, while the time of their removal may vary. They can be illustrated by the following examples: wall scratches, paint chips, spontaneous scratching of the glass, or loosening the silicone next to balcony tiles.  
Taking into account the indicated classification, this paper also analyzes the significance of the defects occurring. The results of the significance tests are presented in Table 6.  
As can be seen, the largest percentage, both globally and for individual buildings, was significant defects. It should be noted here that the class of these defects includes issues related to the regulation of woodwork, not the operation of the intercom system or improper connection of the electrical system. The defects of high significance, on the other hand, constitute a state of emergency, therefore in their case, a large discrepancy in frequency can be observed. For Building B, as much as 19.05% were highly significant defects, while Building C had only 4.88% of such reports. The results of the preliminary research also revealed that about 1/3 of the valid reports concerned minor defects, mainly of a cosmetic nature.