The relevance of the study is driven by the growing need to enhance the energy efficiency of buildings through thermomodernization and the demand for accurate forecasting tools to ensure effective energy management. In the context of climate change and rising energy prices, the selection of optimal forecasting models has become a critical task for housing and communal services as well as urban infrastructure. The aim of the study is to substantiate contemporary approaches to forecasting building energy consumption considering thermomodernization measures, based on the analysis of regression, neural, and hybrid models, in order to identify their advantages, limitations, and practical effectiveness. Methodology. A comparative analysis of recent studies was conducted, covering statistical, neural network, and hybrid forecasting models. The accuracy, scalability, flexibility, and adaptability of models to post-retrofit conditions were assessed. Particular attention was paid to deep learning architectures (LSTM, GRU), hybrid combinations (ARIMA+LSTM, CNN+ELM), and digital twin technologies. Results. It was established that the highest forecasting accuracy is achieved by neural network models, particularly deep architectures and ensembles, with average errors not exceeding 3–5%. Although regression methods are less accurate, they remain useful for baselineestimates and evaluating the impact of climatic variables. The effectiveness of hybrid approaches that combine trend modeling with neural network-based residual learning was demonstrated. The potential of digital twins as a tool for predictive and adaptive energy management was identified. Scientific novelty. For the first time, forecasting models were systematized in the context of building thermomodernization, with the identification of optimal approaches for different types of tasks. The relevance of applying intelligent forecasting systems integrated with digital twins as a new paradigm in building energy management was substantiated. Conclusions. It was proven that accurate forecasting of energy consumption is only possible when accounting for changes caused by thermomodernization and applying flexible models capable of adapting to new building operation conditions. It was determined that the integration of artificial intelligence methods with physical modeling and digital twinsenhances the accuracy and applicability of forecasts for practical energy management. Prospects for further research. It is advisable to develop combined modeling methods that consider behavioral factors in consumption, and to expand the empirical base for assessing the effectiveness of digital twins in retrofittedbuildings of various types.

Abstract. The relevance of this study is driven by increasing energy efficiency requirements for the existing building stock alongside the necessity to preserve historic and architectural heritage. Historic buildings are typically characterized by massive masonry envelopes with high thermal inertia and moisture buffering capacity, which limits the applicability of conventional insulation solutions developed for modern lightweight constructions. Consequently, internal wall insulation of historic buildings requires scientifically substantiated approaches based on comprehensive thermal and hygrothermal assessment of envelope performance and material compatibility.Objective. The objective of this study is to substantiate approaches to the selection and application of insulation materials for internal insulation of historic masonry walls based on a combined thermal and hygrothermal analysis, with particular emphasis on energy efficiency and long-term hygrothermal stability of the building envelope.Methods. The study is based on methods of building physics, normative thermal resistance calculation, and hygrothermal analysis of building envelopes in accordance with the current regulatory framework. Comparative thermal and moisture calculations were performed for internal insulation systems using mineral wool, hemp-based insulation, and cellular foam glass under identical climatic and operating conditions. Material properties were adopted in accordance with national standards, and specialized engineering software was used to ensure consistency and reproducibility of the calculation results.Results. The influence of internal insulation on the thermal and hygrothermal behavior of massive masonry walls typical of historic buildings was analyzed. The results show that insulation materials with comparable thermal resistance values may exhibit fundamentally different hygrothermal performance. Insulation systems with limited moisture-regulating capacity were found to be associated with seasonal moisture accumulation and the formation of an unbalanced annual moisture regime, whereas bio-based insulation materials demonstrated lower moisture accumulation and a more balanced hygrothermal behavior of the envelope. Furthermore, the application of cellular foam glass demonstrated a complete absence of interstitial condensation and zero seasonal moisture accumulation due to its closed-cell structure and high vapor diffusion resistance.Conclusions. The findings indicate that the effectiveness of internal insulation in historic buildings is determined not only by thermal resistance but primarily by the compatibility of insulation materials with the hygrothermal characteristics of traditional masonry. A comprehensive approach to internal thermal retrofitting is substantiated, combining energy efficiency requirements with hygrothermal reliability to ensure durability and long-term preservation of historic building structures.

The study's objective is to conduct a parametric analysis of the components of the building's heat balance, and a parametric analysis of heat flows in buildings with different thermal and physical properties. To this end, a non-stationary multi-zone energy model of a multi-story building was developed, which was then utilized to ascertain the components of the energy balance of a pilot room under various temperature control regimes of the heating system, the massiveness of internal and exterior walls, the insulation of the exterior wall, and contingent on the purpose of the room. Two distinct types of building premises are distinguished: residential and commercial. The analysis revealed that representative rooms oriented towards the north exhibited a 34.8% higher energy consumption for heating needs when compared to rooms oriented towards the south for walls comprising a single brick and a 38.3% higher energy consumption for walls composed of three bricks. Implementing intermittent heating modes has been shown to reduce heat energy consumption by 13.8% and 14.6% for a one-brick exterior wall and 18.2% and 19.9% for a three-brick exterior wall, respectively, for residential and public buildings. The impact of altering the massiveness of internal walls on overall energy consumption is negligible. In contrast, the insulation of exterior walls and replacing windows with more energy-efficient ones exhibit a greater potential for reducing energy consumption in a building. A south-facing model with a constant heating mode in January demonstrated a 39.2% reduction in energy consumption for heating compared to a model lacking exterior wall insulation. Implementing additional intermittent heating modes can achieve energy savings of up to 22.3% for south-facing rooms and up to 21.4% for north-facing rooms. The findings of this study offer valuable insights into the regulation of heating modes in buildings with distinct characteristics in terms of exterior and internal wall composition.

Метою статті є аналіз даних температури зовнішнього середовища з кліматичних баз даних України та Meteonorm з використанням історичних, поточних та прогнозованих даних для оцінки потенціалу використання відновлювальних джерел енергії. Методика включає використання методів синтезу та аналізу кліматичних даних. Результати включають аналіз температур зовнішнього середовища, як кліматичних данних, що мають найбільший вплив на енергоефективність будівель та забезпечення комфортності. Особлива увага приділена аналізу екстримальних погодних умов, таким як: хвилі спеки, тропічні ночі, морозні дні та холодні дні. В статті проведено порівняння нормативних та кліматичних даних за історичний та поточний періоди, а також майбутніх сценаріїв розвитку зміни температури зовнішнього середовища під впливом антропогенних факторів. Встановлено, що з кожним наступним сценарієм RCP 2.6, RCP 4.5, RCP 8.5 відбуватиметься швидше зростання середньорічної температура зовнішнього середовища. У Києві до 2100 року температура зовнішнього середовища згідно RCP 2.6, RCP 4.5, RCP 8.5 зросте на 1,2°C, 3,1°C, 5,8°C відповідно. У Одесі ріс температури до 2100 року відповідно RCP 2.6 стоновитиме 1,1°C, за RCP 4.5 – 2,9°C, за RCP 8.5 – 5,3°C. Результати також збільшення кількості теплових хвиль і тропічних ночей, та скорочення кількості морозних та холодних днів. Наукова новизна полягає у обґрунтуванні використання міжнародних кліматичних баз даних для проектування систем енергозабезпечення будівель з використанням відновлювальних джерел енергії в контексті змін клімату та діючої нормативної кліматології України. Практична значимість результаттів дослідження дозволяє оцінити відмінність кліматичних різних регіонів України, їх зміни в контексті історичного, поточного та майбутніх змін клімату. Також, в статті проведенно аналіз екстремальних погодних даних, що є актуальним в контексті проектування інженерних ситем та джерел будівель.

Considering the military impacts in Ukraine and the global push toward decarbonization, we evaluate opportunities for achieving a low-carbon transformation in the construction sector. In particular, we analyze the effects of enhancing the building's thermal insulation and supplying heat via renewable energy sources during the modernization of an existing administrative building in Ukraine to meet European Union requirements. This analysis considered economic, technical, and environmental factors. Thus, we present the results of dynamic modeling of the building's energy consumption at different levels of building insulation using the DesignBuilder software and provide an integrated forecast of the payback period for investments in improving the building's thermal insulation and using heat supply options such as heat pumps and pellet boilers). To assess emissions reduction of the proposed building modernization options, an analysis of the existing national methods of calculating carbon dioxide emissions was carried out. The use of photovoltaic panels for electricity supply was considered in the PV*SOL software as an option to reduce carbon dioxide emissions, which can be taken into account through the Net Billing mechanism, including when using a heat pump for heating.

The purpose of this work is to analyze the current state of implementation of energy efficiency projects for the housing and communal sector in Ukraine, identify the main obstacles and promising ways to overcome them. The article analyzes the main barriers that complicate the implementation of energy efficiency measures in the energy sector of Ukraine in the period from February 24, 2022 to the beginning of 2025. The review covers the following key groups of barriers: economic, technical and organizational, regulatory and social. Particular attention is paid to the impact of martial law, destruction of infrastructure and lack of investment on the dynamics of the implementation of energy efficiency policy. Various limitations in the formation of the cumulative impact on the energy sector are assessed, a comparative assessment of the significance of the barriers is carried out and strategic directions for overcoming them are proposed in the context of post-war energy recovery. The post-war period opens a window of opportunity for Ukraine on the principles of sustainability and climate neutrality, which will allow Ukraine to become an energy-independent state. The results of the study can serve as an analytical basis for the development of effective state policy in the energy sector, in particular in terms of strategic energy efficiency planning, adaptation of national legislation to EU requirements and implementation of sustainable development goals. The results of the study will be useful for the formation of regional development programs, attracting donor and technical assistance within the framework of projects to rebuild the energy system of Ukraine on the basis of energy independence, in particular in terms of risk assessment.

During the pandemic and periods of martial law, educational institutions in Ukraine implemented various forms of organising the educational process, combining in-person and remote classes. As a result, there has been a decrease in the level of use of building premises. The analysis of the characteristics of energy consumption in these conditions requires additional attention. In this study, a dynamic energy model of the building was created using the educational building of Igor Sikorsky Kyiv Polytechnic Institute as an example. Energy consumption for heating needs was determined for normal operating conditions and quarantine conditions in Ukraine (only a specific part of the premises is being operated, ensuring that the standard temperature value is maintained while people are present). Based on the results of the study, the features of the energy consumption of the building during quarantine/martial law restrictions, subject to the partial use of the building, were analysed, and the main disadvantages of such a mode were identified. For the educational building of the university, the total energy consumption for heating needs depends on the number of rooms that are actively used, and the modes of regulation of heating and ventilation; the consumption can decrease depending on the chosen scenario by 61 %, 56 %, and 34 % in quarantine mode. The findings indicate that the efficiency of regulation modes can decrease by more than four times when compared to normal mode due to internal heat exchange with unoccupied rooms.

Energy efficiency is one of the key topics that have become very relevant in recent years. In buildings, as the final consumers of energy, the greatest potential for energy saving is concentrated. And at the same time, an important component of energy efficiency is the optimal use of energy resources, where the lion's share falls on the consumption of thermal energy. In this context, heating schedules become an important tool for achieving this goal. In this article, the authors investigate the energy efficiency of different heating and ventilation modes for a school located in two climatic zones of Ukraine: I (Kyiv) and II (Odesa). Using the Design-Builder software, which is based on the EnergyPlus model, the authors model five intermittent modes for the heating and ventilation system. The authors also compare the energy efficiency of different heat sources: a boiler on biofuel, a heat pump and a solar panel. It was found that the introduction of heating modes according to the schedules allows to reduce energy consumption for heating by 10 % to 20 % depending on the mode and climatic zone, and the use of renewable energy sources based on the introduction of intermittent heating and ventilation modes for the school shows efficiency at 79 %-80 %. The authors also analyze the impact of thermomodernization of enclosing structures on the energy efficiency of buildings. The conclusion on the introduction of intermittent heating modes for non-insulated buildings is an extremely effective measure for energy saving, and the impact of the measure on energy saving of the building will be noticeable even after thermal insulation. The implementation of all improvements allows reducing energy consumption for heating by 90 %.

Мета. Дослідження спрямоване на аналіз динамічного енергетичного моделювання будівель з використанням програмного забезпечення EnergyPlus та DesignBuilder. Основна мета полягає в оцінці енергетичної ефективності, повітряної якості та енергетичного балансу будівель з врахуванням різноманітних аспектів, таких як повітрообмін та динамічні зміни в температурі та вологості. Методика. В роботі використовувались програми EnergyPlus та DesignBuilder для створення детальних динамічних моделей будівель. Основна увага приділялась моделюванню повітрообміну та вивченню енергетичного балансу. Різні алгоритми моделювання повітрообміну порівнювались для визначення їх впливу на енергетичну ефективність. Результати. Досліджено енергетичні потоки в будівлях на основі динамічних енергетичних балансів для періоду опалення. Проведено поглиблений аналіз впливу повітрообміну в динамічних енергетичних балансах досліджуваної кімнати житлової будівлі. Наукова новизна. Це дослідження пропонує новий погляд на динамічне енергетичне моделювання будівель, розширюючи знання в цій галузі через спрямовану увагу на аспекти повітрообміну та енергетичного балансу. Результати внесуть важливий вклад у розвиток підходів до підвищення енергоефективності, створюючи нові можливості для практичного застосування в інженерному проектуванні та будівельній експлуатації. Практична значимість. Отримані результати є важливим внеском для інженерів та проектувальників, розробляючи стратегії зменшення енергоспоживання та оптимізації енергетичного споживання будівель. Дослідження може слугувати вказівником для практичного впровадження динамічного моделювання в плануванні та експлуатації будівель для досягнення оптимальної енергоефективності.

Condensing boilers can achieve significantly higher efficiency than conventional ones due to possibility to recover latent heat of vaporization from the flue gas. But it can be achieved when return temperature of heating system is sufficiently low (below the dew temperature of the flue gas), which directly depends on thermal modes of the heat consumer. The work evaluates ways of increasing performance of a condensing boiler by implementing energy efficient solutions in buildings. It has been found that the biggest increase in boiler efficiency (by 6.6 %) can be achieved by switching to low-temperature heating systems. Applying intermittent heating is in second place in terms of the possibility of increasing boiler efficiency (up to 3.5 %). Insulation of the house also increases boiler efficiency, but less than the previous two solutions (up to 2.7%). Complex analysis has shown that reducing return temperature of the heating system by increasing heating area or using more efficient radiators, switching to intermittent heating and improving building insulation can increase the average seasonal efficiency of the condensing boiler by 8.8%. Seasonal natural gas consumption can be reduced by 69%.

This article presents the primary analysis of data from the distribution accounting system of an apartment building, displays of individual groups of distributors, made a comparison between groups of consumers to identify factors affecting the accuracy of distribution, and formulated the main theses of further research. As part of the analysis, data from the distribution devices of the thermal energy distribution accounting system for heating an apartment building in Bila Tserkva were used. The distributed consumption of apartments and the indirect effect of the full-scale invasion of the Russian Federation on the behavior of heating consumers regarding the individual regulation of heat energy consumption for heating were analyzed. The possible influence of the location of the premises in relation to the number of floors on the level of heating consumption was also analyzed. For the analysis, the collected readings from the distributors were used in the primary form, and interpreted in the distributed form as the distributed energy consumption for space heating, as well as the specific distributed consumption for comparison between apartments without the influence of the difference in area. The grouping of premises was carried out by apartment, by floor, by apartment risers, and the general household energy consumption for heating. During the analysis of the process of interpretation of the displays, it was found that the consumption of apartments with individual heating systems was not taken into account, as a result of which it is impossible to sufficiently draw conclusions about the behavior of consumers regarding heating regulation. Further research is needed to clarify the values ​​of the correction coefficients when interpreting the readings, in general, to identify the feasibility of using some correction coefficients, to develop changes to the method of distribution accounting of heat energy for heating, to study the behavior of consumers at a given level of individual control of energy consumption.

Improving the energy efficiency of buildings is an important component on the way to energy efficiency of the country as a whole. The article investigates the impact of implementing various combinations of energy saving measures and their impact on the energy efficiency class of buildings, using the example of the educational building of the Igor Sikorsky Kyiv Polytechnic Institute (Kyiv). The existing state of the building corresponds to the energy efficiency class "G". A complete thermal modernization of the building in accordance with the current requirements for thermal protection can reduce energy consumption by the building by up to 44 % and reaches the energy efficiency class "E". It was found that the introduction of intermittent heating modes can save 12 % for an un-insulated building and 7 % for an insulated building. Heat recovery in ventilation systems can save 23 % and 48 % of energy for non-insulated and insulated buildings, respectively. Implementation of a comprehensive thermal modernization of the building envelope in combination with heat recovery in ventilation systems in combination with intermittent operating modes allows to move to energy efficiency class "B". When replacing heat supply sources after a complete thermal modernization of a building, it can move to energy efficiency class "A" when using heat pumps.

The aim of this study is to apply dynamic exergy and energy analysis to the building envelope. The peculiarity of the analysis is that it considers the dynamic energy and exergy model of the room of the apartment with a one-second time step, taking into account the accumulation of energy and exergy in external and internal enclosures, as well as heat fluxes between them and solar radiation also. It is shown how the structure of the exergy balances of the room changes if the reference point is the temperature in the room, ambient temperature, and 0(degrees)C. The proposed analysis approach is to use different reference points for different applications of exergy analysis, where the oscillations of exergy will be smaller. The study demonstrates that the accumulation of exergy by internal partitions accounts for 2% depending on the exergy reference point.

Мета. Аналіз фактичного стану прихистків для тимчасового проживання внутрішньо переміщених та малозахищених верств населення, а також визначення шляхів підвищення рівня комфортності та енергоефективності шелтерів. Методика. Первинне обстеження шелтерів, розміщених в різних областях України, для аналізу їх поточного стану з точки зору забезпечення умов комфортності та енергоефективності, проводилось на місцях, методами спостереження та опитування. Більшість прихистків входять до складу будівель та не є самостійними об’єктами будівництва. Тож для них визачалися приведені опори теплопередачі огороджувальних конструкцій за ДСТУ 9191:2022 [1] та енергоефективність інженерних систем згідно з ДСТУ EN 15232-1:2017 [2]. Результати. За результатами обстеження сформовано пропозиції для забезпечення та підвищення комфортних та енергоефективних умов у шелтерах. У роботі також висвітлено аспекти, які потребують спільних зусиль влади, громадських організацій та міжнародних донорів для покращення умов проживання в прихистках. Наукова новизна. Враховуючи не достатню кількість досліджень стану шелтерів у Європі, та актуалізацію цих питань для України в останні два роки, проведений аналіз є новим та своєчасним тому що рівень теплового комфорту в житлових приміщеннях має значний вплив на емоційний та фізичний стан мешканців. Практична значимість. В опалювальний період та в умовах масових ворожих атак на енергетичну інфраструктуру України важливими є питання забезпечення комфортного та енергоефективного мікроклімату в прихистках для внутрішньопереміщених та малозахищених верств населення. Проведене дослідження засвідчило актуальність проблеми енергоефективності шелтерів в Україні.

У зв'язку з ростом вимог до сталого розвитку та раціонального використання ресурсів, особливо в контексті директив Європейського Союзу щодо енергоефективності будівель, зростає увага до розробки рішень, спрямованих на забезпечення практично нульового енергоспоживання у нових громадських спорудах. У роботі розглядається актуальність впровадження енергоефективних технологій у громадській споруді, відповідно до європейських стандартів енергоефективності, так як використання затінення в літній період, коли інтенсивне сонячне випромінювання може призводити до перегріву приміщень, збільшення витрат на кондиціонування та негативного впливу на здоров'я та комфорт. Зокрема, обговорюється необхідність використання пасивних методів, таких як затінення вікон, для зниження енергоспоживання та підвищення комфорту у літні місяці. Об'єктом дослідження є дошкільний навчальний заклад у м. Київ. У дослідженні враховуються наступні фактори: теплові надходження від обладнання, освітлення, та від людей. Використовуючи програмне моделювання DesignBuilder, було оцінено енергопотребу на охолодження та енерговитрати освітлення для варіанту з та без затінення, включаючи статичне затінення та, рулонні жалюзі. Результати вказують на те, що статичне затінення от найбільш ефективним, і для репрезентативної знижує енергопотребу на охолодження на 74,98 кВт∙год порівняно з варіантом без затінення, але при цьому призводить до збільшення енерговитрат на освітлення на 4,63 кВт∙год. Зауважено, що встановлення рулонних жалюзів з внутрішньої сторони може бути найменш ефективним рішенням через збільшення витрат на освітлення та незначне зменшення енергопотреби для охолодження. Оцінено вплив орієнтації вікон та розташування затінення на ефективність. Крім того, аналіз впливу затінення на радіаційну температуру показує, що статичне затінення сприяє зниженню температури в приміщенні, поліпшуючи тепловий комфорт у літній період

Studying the frequency of air exchange in residential buildings is important from the point of view of ensuring microclimate conditions in the room for residents, as well as ensuring an appropriate level of energy efficiency. The purpose of this study is to experimentally study the concentration of CO2 in a typical apartment using stationary CO2 sensors and determine air exchange based on mass balances. The object of the study is a one-room apartment in a family-type dormitory in the city of Kyiv. The dormitory has ducted natural ventilation. As part of the study, actual and experimental measurements of the concentration of carbon dioxide were carried out in the premises of the living room, kitchen, corridor of the apartment and in the ventilation duct leading to the kitchen. Experimental research conditions were created by artificial injection of carbon dioxide. According to the research results, the air exchange rate in the apartment was at the level of 0.74 h-1 for the living room, 0.66-0.81 h-1 for the corridor, 3.4 h-1 for the kitchen, under conditions when the supply air enters through windows and entrance doors. The results of the research can be used to develop energy-efficient strategies for improving air quality in residential premises.

In this paper, a critical analysis of technical literature, methodological guidelines and rules, scientific work of Ukrainian and foreign experts on aspects of the organization of distribution accounting of thermal energy for heating in multi-apartment buildings with vertical heating systems is carried out. An important stage of the strategy for improving the building's energy performance is to organize individual control of energy consumption. For the organization of individual consumption control for heat energy in buildings with vertical heating systems, distribution accounting systems for thermal energy are becoming widespread. Within the framework of this study, a number of aspects and shortcomings in technical standards and legal acts regulating the rules for the organization of distributive accounting would be revealed. Three groups of aspects are defined: technical - related to the justification of using the method of distribution of heating costs according to the types of accounting, temperature measurement, rules for the place of installation of devices, and the presence of a significant number of correction coefficients; methodical - rules for organizing and conducting screenings, interpretation and consideration of correction coefficients, significant simplifications in determining important correction coefficients, lack of methodical provision to prevent abuse by consumers with individual heating systems in buildings; behavioral - the ability to monitor one's own savings, motivation for individual regulation, the presence of individual control over heating consumption without proper control of the temperature regime and flows between apartments causes the possibility of uncontrolled parasitic consumption of thermal energy at the expense of neighbors. Formulated aspects and shortcomings of the existing distribution accounting system require in-depth study in order to avoid unreasonable simplifications, improve the accuracy of the system, and increase the fair distribution of payment for consumed thermal energy among consumers.

Most multi-apartment residential buildings built in the 20th century in Central and Eastern Europe do not meet modern energy efficiency requirements. The main part of the thermal energy consumed by buildings is used to heat the supply air from outside, which is the largest share in the energy balance of buildings. The purpose of this research is a parametric analysis of influencing factors on the frequency of air exchange in the room and an experimental study of the concentration of CO2 in a typical apartment. The object of the study is a one-room apartment in a family-type dormitory in the city of Kyiv. The dormitory has ducted natural ventilation. In the work, experimental measurements of the concentration of carbon dioxide were carried out in the premises of the living room, kitchen, corridor of the apartment and in the ventilation channel in the summer period. The indicator gas method was used to measure the air exchange rate. During air infiltration, the average rate of air exchange in the absence of people in the apartment in the living room was 2.41 h-1, in the corridor - 2.34 h-1, in the kitchen - 0.57 h-1. Under exfiltration conditions, the average values were lower: living room – 0.24 h-1, corridor – 0.94 h-1, kitchen – 0.52 h-1. The dependence between wind directions and the phenomena of infiltration and exfiltration in the premises of the apartment was recorded. As a result of the research, it was established that the most influential parameter of the change in the concentration of CO2 in the room is the release from people's breath. It follows from the simulation results that to ensure the regulatory level of CO2 concentration is not higher 1500 ppm, it is necessary to observe the air exchange in the considered room not lower than the level of 1.51 h-1 for conditions when 2 people are constantly in the room That is, the mass balance of CO2, which takes into account the number of inhabitants, can be an attractive alternative method for predicting the intensity of ventilation of a building.

The concept of implementation of the state policy in the field of ensuring the energy efficiency of buildings in terms of increasing the number of buildings with close to zero energy consumption and the National Plan for the increase in the number of buildings with close to zero energy consumption are aimed at achieving the goals set out in the Energy Performance of Building Directive, which indicates significant steps towards improving the energy efficiency of the Ukrainian construction sector. According to the above regulations, a prerequisite for new construction and renovation of existing buildings is to ensure a high level of thermal insulation of the building and the use of renewable sources to cover energy consumption. The work carried out a feasibility study of the modernization of an office building in the city of Kyiv to the level of a highly energy-efficient building using a heat pump to provide the necessary heat supply. Estimation of generation of required heat supply of the building by the heat pump and used electrical energy by the heat pump is based on the simulation results in the GeoTSOL software environment. In order to assess the economic attractiveness of the project for upgrading an existing building to the level of a highly energy-efficient building using renewable sources for heat supply, the calculation of the energy demand for heating in the Design Builder software environment and the integral costs for heating the building using renewable and traditional energy sources at different levels of thermal protection was made. The results obtained indicate attractive, both from an economic and environmental point of view, the possibilities of implementing the construction of a highly energy-efficient building that uses renewable energy sources for heat supply.