Although the life cycle assessment of multi-apartment residential buildings has been used in the construction industry since 1990, there is not yet an internationally recognized methodology for the assessment and organization of life cycle inventory data for buildings. Building life cycle assessment is particularly complex because buildings are more complex than most other products. The service life of buildings is long, which in turn makes it difficult to predict the entire life cycle of a building or structure. Buildings can also undergo changes throughout their life cycle, potentially leading to a significant structural difference between a building that is demolished at the end of its life and a building that was originally built. In addition, although most other products do not have a significant impact throughout the life cycle, the life cycle of buildings is often a major factor in the overall life cycle impact. Also, there are many stakeholders in the construction industry, including designers, builders and users. Real estate managers, when performing the management process in a certain or specific multi-apartment residential house, should be guided by the following main principles: the aspect of possibilities of technological improvements; aspect of the operational activities to be performed; economic aspect and mutual communication aspect. Knowing the life cycle of an apartment house, which can be tentatively expressed in years and divided into life cycle phases, and after dividing the technological processes into priority phases, the apartment house manager can strategically plan the management functions to be performed. The life cycle of a multi-apartment residential house allows the building manager to develop a long-term plan for the use of financial resources, which in turn would generate possible additional income. Thus, it is permissible that a house savings fund will be established for a certain period of time, which will be able to be used when capital investments are needed to renovate the property. In building life cycle assessment, the boundaries of the system for creating life cycle assessments differ significantly depending on which elements, life cycle phases and environmental loads are included. A common life cycle assessment system for buildings is needed to increase the comparability and relevance of case studies.