To date, energy consumption in buildings accounts for a significant part of the total amount of energy consumed worldwide. The effect of ageing and degradation of various building components is one of the least studied reasons for the possible increase in energy consumed in buildings over time. In addition, there is a clear lack of practical guidelines that would help specialists take this factor into account. In this paper, an attempt is made to assess a possible change in the energy performance of buildings due to the degradation of their various components (insulated glass units, thermal insulation, airtightness, solar reflectivity of the building envelope, and photovoltaic modules). Detached and apartment buildings in hot-humid climates with reference to the United Arab Emirates (UAE) were considered. The study was based on simulation research using EnergyPlus, in which the initially collected data on the possible deterioration of the properties of various building components was used for dynamic thermal simulation of selected buildings. The results showed an increase in energy consumption for cooling in detached houses might reach up to 9.53–38.4% over 25 years for more airtight and insulated buildings and 12.28–34.93% for less airtight and insulated buildings. As a result, certain patterns of changes in energy consumption for cooling buildings were established, based on which a set of guidelines was developed. These guidelines can help specialists in various fields better understand the trends in the energy performance of buildings under the influence of degradation processes and take appropriate measures.

Oxalic acid is an important separation agent in the technology of lanthanides, actinides, and transition metals. Thanks to the low solubility of the oxalate salts, the metal ions can be easily precipitated into crystalline material, which is a convenient precursor for oxide preparation. However, it is difficult to obtain oxalate monocrystals due to the fast precipitation. We have developed a synthetic route for homogeneous precipitation of oxalates based on the thermal decomposition of oxamic acid. This work primarily concerns lanthanide oxalates; however, since no information was found about oxamic acid, a brief characterization was included. The precipitation method was tested on selected elements (Ce, Pr, Gd, Er, and Yb), for which the kinetics was determined at 100 °C. Several scoping tests at 90 °C or using different starting concentrations were performed on Ce and Gd. The reaction products were studied by means of solid-state analysis with focus on the structure and morphology. Well-developed microcrystals were successfully synthesized with the largest size for gadolinium oxalate.

The issues of reducing energy consumption in buildings and their decarbonisation are currently among the most pressing. However, such an important aspect of the problem under discussion as the impact of unavoidable degradation processes on energy demand in buildings remains poorly understood. In addition, there are only a limited number of practical guidelines that can be used to take this factor into account at the design stage and during the further operation of buildings. The aim of this work was to assess the potential impact of component degradation and ageing on heating energy consumption in buildings, including insulated glass units, thermal insulation, airtightness, heat recovery of mechanical ventilation systems, and photovoltaic modules. The detached and apartment buildings were considered to be in a cold climate in the context of the Republic of Belarus. The study was based on simulation research using EnergyPlus. As a result, it was found that a possible increase in heating energy consumption might reach 17.6–61.2% over 25 years in detached houses and up to 23.6–89.8% in apartment buildings. These indicators turned out to be higher than the previously identified values for cooling energy consumption in a hot–humid climate. Based on the findings, recommendations for considering the degradation factor in cold climates in practice were developed, which were compared and integrated into the author’s existing guidelines.