The article presents the results of research carried out in construction companies among employees involved in the organisation and management of construction projects. The research concerned factors and their impact on decisions regarding the planning of quantitative employment workforce at a construction site. Based on individual assessments of individual factors, average assessments were calculated and hierarchies of the factors examined were made. In the second part of the article, the dispersion coefficient of relative classification was used to assess the reliability of the opinions collected. The content presented is a continuation of the work of the authors on the subject of employment planning at the construction site.

The main goal of the studies was to collect information on the impact of the identified risk factors on the amount of costs incurred in the life cycle of buildings. The own studies were focused especially on residential and non-residential buildings. The studies consisted in obtaining expert opinions on the subject of the research involves in the non-random (arbitrary) selection of a sample of respondents from among specialists corresponding to the industry purpose of the studies and the research material. The research used the expert questionnaire method. The studies were divided into three stages. In the first stage, the identification and division of risk factors in the life cycle of buildings was performed. Then, experts assessed 45 selected risk factors that may affect the amount of costs incurred in the life cycle of buildings. In the last step, the research results were developed in the form of a checklist knowledge base, containing information about the potential impact of the identified risk factors in the life cycle of buildings on the amount of the corresponding components of life cycle costs.

Planning maintenance costs is not an easy task. The amount of costs depends on many factors, such as value, age, condition of the property, availability of necessary resources and adopted maintenance strategy. The paper presents a selection of models which allow to estimate the costs of building maintenance, which are then applied to an exemplary office building. The two of the models allow a quick estimation of the budget for the maintenance of the building, following only indicative values. Two other methods take into account the change in the value of money over time and allow to estimate, assuming the adopted strategy and assumed costs, the value of the current amount allocated to the maintenance of the building. The final model is based on the assumptions provided for in Polish legislation. Due to significant simplifications in the models, the obtained results are characterized by a considerable discrepancy. However, they may form the basis for the initial budget planning related to the maintenance of the building. The choice of the method is left to the decision makers, but it is important what input data the decision maker has and the purpose for which he performs the cost calculation.