## 3 Methodology and Materials  
A methodology for identifying and assessing the impact of selected factors on the generation of defects during the construction of residential buildings was developed. This methodology consists of three stages:  
* The first stage included in situ tests carried out on construction sites, which consisted of:
* identifying defects in residential buildings during technical acceptance;
* identifying factors occurring at various stages of the construction process that affect the quality of a residential building.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**No. of Factor** & **Literature Item** & **Type of Factor** & **Description** \\ \hline
1 & [10,14,20,22,24,28] & Errors in the design documentation &
\begin{tabular}{c} design errors, faulty structural and architectural design, ambiguity of design details, omission to take into account the conditions of use (maintenance) at the design stage, defects in construction drawings \\ lack of design standards, incompatibility of the project with existing technology \\ \end{tabular} \\
2 & [4] & No legal basis for the design & lack of design standards, incompatibility of the project with existing technology \\
3 & [22,24] & Making changes to the structure & changes in structure during construction and use \\
4 & [10,16,22,23,25] & Qualifications and skills of workers & unskilled contractors, insufficient skills of workers, contractor errors \\
5 & [10,22,23,25,27] & Qualifications and skills of the management staff & qualifications, experience and knowledge of the manager, skills related to construction \\
6 & [10,24,25,29] & Quality management & lack of quality management during construction, lack of control during construction, poor supervision on site involvement of the supervisory team, involvement of other employees \\
7 & [27,33] & Engagement &
\begin{tabular}{c} requirement of the supervisory team, involvement of other employees \\ \end{tabular} \\
8 & [25,29,30] & Construction management skills & poor planning and scheduling, delays in decision making, planning/programming \\
9 & [24,25,30] & Team communication & lack of communication, level and quality of formal and informal communication, organizational culture, lack of communication between the designer and contractors \\
10 & [10,20] & Lack of work teams & lack or deficiency of resources \\
11 & [10,20,21,22,23] & Delivery of materials not in accordance with specifications & non-compliance with specifications, incorrect specifications, defects resulting from material specifications, use of unqualified trade subcontractors \\
12 & [10,20,21,22,23] & Poor materials management & poor material management, improper use of building materials, damage to materials during construction \\
13 & [27] & Climatic influences & difficult climatic conditions, bad weather conditions \\
14 & [14,25] & Financial difficulties, time & client’s financial uncertainty, cost pressure, time pressure \\
15 & [13] & End customer engagement & participation of the end customer in technical acceptance \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of research results on factors influencing quality in construction.  
In the second stage, in order to determine the strength of the influence of factors on the generation of defects, statistical analyses of the survey results and the results of analyzing defects were performed. An assessment of the impact of factors on quality was made in relation to the examined investments. Discriminant analysis was used in the calculations.
* In the third stage, conclusions from the research were formulated.