The article explores the potential of Digital Twin (DT) technology in the design and dynamic assessment of the energy performance of multi-family buildings. Traditional approaches to building energy assessment provide static data that do not account for changing operational conditions and lack continuous energy consumption-monitoring capabilities. The use of Digital Twin enables monitoring and analyzing of the building’s energy parameters at every stage of its life cycle. The article presents the application of DT technology for assessing energy performance at the conceptual stage and in the early phases of design. These parameters must meet legal requirements. Validation conducted on four multi-family buildings demonstrated high accuracy, with the average difference between predicted and actual energy performance (EP) values below 3.5%. Thanks to the DT model, it is possible to determine energy parameters already at the conceptual stage, which helps avoid costly changes in later project phases. Early determination of these parameters also allows for accurate estimation of design and investment costs. Tests of the proposed solution were conducted on several multi-family buildings, comparing preliminary data with final results. The research results show that DT technology allows for precise planning of energy performance at the conceptual and preliminary design stages. This reduces operational costs, increases energy efficiency, and better adapts buildings to changing technological and legal conditions.

This article addresses issues related to the quality of design and subsequent management of multi-family residential buildings in the context of their energy supply. The framework of the analysis carried out here are pro-environmental legal regulations currently in force in Poland. This article describes the impact of these regulations on the design process and the role of the designer. The requirements have been defined and the constraints have been identified. A number of factors directly related to the nature and parameters of the designed buildings and their location have been taken into consideration. On the basis of this study, the impact of legal regulations both on the method of energy supply in the buildings and on their later use and management have been presented. Positive and negative aspects of the analyzed regulations have been indicated and directions for their evaluation and optimization have been proposed. The research was carried out using real buildings, both completed and in the design phase. This article is based on the authors’ extensive experience in designing multi-family residential buildings in Poland.

While trying to understand the current need for continuity of thoughts and ideas derived directly from the modernist trend with regard to multi-family housing, it is doubtlessly necessary that we need to make a synthetic assessment of the quality of Polish architecture over the last several decades. This period was characterized by an extremely diverse, multi-directional and multifaceted way of a building's creation. In the face of a generally noticeable regression, the past several years, recognized so far as indisputable paradigms of culture, brought an inconsistent mix of independently consecutive different tendencies and aesthetic needs. The specific state of permutation, peculiar intellectual vacuum created by rejection of the existing rules and shortage of new ones, must have led to anarchy in architecture manifesting in the omnipresent "all-ism". Against this background, it is difficult but possible, to find a clearly defined style, direction or the need to continue modernist thought on the example of modern housing. Dating back to the seventies of the twentieth century, we can observe activity of the generation of architects, where we can find the attempts to think about architecture on the basis of patterns of contemporary avant-garde world's architecture. So-called "modernism", which was in fashion at that time, resulted in frequent borrowings of formal and functional ideas, yet it brought a number of successful realizations of timeless architectural values, expressed in a clear idea and clearly defined form. The second half of the seventies was dominated by the omnipresent classification and prefabrication based on "the systems of industrialized buildings", which defined the character of the housing architecture. This gave rise to a gradual limitation of individual creativity for the benefit of use and reproduction of typical projects adapted to the needs of particular locations. The economic crisis of the 1980s, as a result of decline of the socialist economy, also resulted in the stagnation of construction activity. An example of the existence of any design process remained the urban design of large housing estates based on the consistently simplified and limited construction systems of multi-family buildings. Thus, monotony and repetition became a ubiquitous standard and the only aesthetic criterion that defined the architectural space of cities at that time. The political and economic transformations that took place after 1989 as well as a strong feeling of freedom, regained after years, triggered off revolutionary changes in thinking that resulted in a multitude of events taking place in architecture, and consequently in the diversity and variability of aesthetic tendencies. Therefore, it is difficult to believe that the buildings constructed at that time were a direct indicator of a post-modernism idea, which, locally, were a sort of specific alibi, resulting from the momentary, deep need to rebuild the times of modernism, unfairly reduced in our reality only down to the criticism and negation of a ubiquitous residential large-panel housing. Luckily, the end of the nineties brought a noticeable reassurance of these tendencies. Uncertainty and indecisiveness, and hence the multitude of ideas and stylistic themes that provoked safe passivity and aesthetic borrowings, have been replaced by escapism from "eclectic postmodernism" towards "neo-modernism" as a more sophisticated form of convention. As a consequence, there appeared objects with a balanced form, not giving in the need to draw directly from classical patterns and not succumbing to the intrusive and chaotic need to recover from the past. Despite the fact that the possibilities of a designer's creative expressions have become apparently expanded in new, modern economic realities, the designer's creation has at the same time been very limited. His freedom and free expression were additionally determined by the investor, whose opinion on the social and economic expectations, and thus on the architecture and purely aesthetic issues, has in many cases become superior. However, numerous examples of contemporary multi-family buildings, which are also the result of their own professional experience, offer prospects that the stage of total abandonment of the idea of modernism turned out to be apparent and was provoked by rather temporary emergence of various aesthetic tendencies, which are the result of views denying the architecture, commonly regarded as impersonal.