Improving technical and economic solutions for the reconstruction of enterprises in the construction industry

The purpose of the study was to substantiate and improve technical and economic solutions for the reconstruction of enterprises in Ukraine’s construction industry, taking into account current trends in energy efficiency, the digitalisation of production processes, and the transition to the use of alternative fuels. The study had a theoretical and analytical nature and was conducted using computational-and-evaluative, structural system, analytical, and comparative methods. The methodological basis comprised the international standards ISO 50001:2018, 14044:2006, 15686-5:2017, and the DSTU EN 16247-3:2021. Computational-and-evaluative modelling of the heat-generation systems of a boiler house with a capacity of 10 t of steam/hour showed that, when switching from natural gas to biomass, specific energy costs decreased by 21.2%, and CO2 emissions – by 80.4%; when using pyrocarbon – by 17.3% and 58.9%, respectively. The technical efficiency coefficient was 81.7% for biomass, 84.2% for pyrocarbon, and 86.4% for natural gas. The integral efficiency indicator E(int) exceeded the baseline level of 1 – reaching 1.28 for biomass and 1.19 for pyrocarbon. The “costs – emissions” diagram with a coefficient of determination R2 > 0.9 demonstrated a stable negative correlation between economic costs and environmental emissions, outlining an optimality zone below 450 UAH/GJ and 0.025 t CO2 /GJ. The harmonisation of the provisions of the standards ensured methodological consistency between energy planning, life-cycle assessment, and cost management, which made it possible to form an integrated decision-making model for the reconstruction of industrial facilities. The proposed combination of digital energy management, environmental-economic balancing, and life-cycle costing confirmed the possibility of achieving energy efficiency ≥0.85 under conditions of minimising the cost of heat generation and decarbonising production processes. The practical significance lay in the possibility of applying the obtained results for the modernisation of construction enterprises and the adaptation of Ukrainian industry to the EU sustainable-development requirements