Energy Effects of Retrofitting the Educational Facilities Located in South-Eastern Poland

Building Energy Audits—Diagnosis and Retrofitting towards Decarbonization and Sustainable Cities

A collection of twelve papers published in Energies, in a Special Issue on “Building Energy Audits-Diagnosis and Retrofitting”, was bound together and published in 2021, focusing on the built environment. The aim was to systematically collect and analyze relevant data for obtaining adequate knowledge on the energy use profile of buildings, and was extended for the sustainability assessment of the built environment. To date, all papers have been very well received, attaining a total of 97 citations and over 15,300 views. The papers addressed historic and various building types, baselines for non-residential buildings from energy performance audits and from in-situ measurements, monitoring and data analysis, assessment of indoor environmental quality, model calibration and verification of energy savings, along with an urban audit and rating method for assessing the sustainability of the built environment. Following on from the success of this Special Issue, the decision was made to reopen and extend it to include papers related to decarbonization and sustainability, at building, city, region, and national scales. This Editorial reviews the performance of the first Special Issue and outlines the second volume on Building Energy Audits-Diagnosis and Retrofitting Towards Decarbonization and Sustainable Cities, as a Special Issue in Energies.

Old and Modern Wooden Buildings in the Context of Sustainable Development

Construction is a powerful industry that is not indifferent to the environment. Neither the maintenance of buildings in a proper technical condition nor their eventual demolition is indifferent to the environment. The main threats to the environment are still the inefficient use of construction materials and energy needed for their production and installation, as well as the emission of harmful substances to the environment at the stage of operation of buildings and their demolition. This article discusses the importance of wood as a renewable material in terms of its physical and mechanical properties. The restoration of forest areas is of great importance to the global ecosystem and the sustainable development system, reducing the threat of global warming and the greenhouse effect by reducing CO2 levels. In addition, demolition wood can be reused in construction, can be safely recycled as it quickly decomposes, or can be used as a source of renewable energy. The preservation of existing timber-framed buildings in good condition contributes to a lower consumption of this raw material for repair, which already significantly reduces the energy required for their manufacture, transport, and assembly. This also reduces the amount of waste that would have to be disposed of in various ways. Both at the stage of design, execution, and then exploitation, one forgets about the physical processes taking place inside the partitions and about the external climatic influences of the environment (precipitation, water vapor, and temperature) on which the type, intensity, and extent of chemical and biological corrosion depend to a very high degree. This paper presents examples of the influence of such impacts on the operational safety of three selected objects: a feed storehouse and an officer casino building from the second half of the nineteenth century and an 18th century rural homestead building. The research carried out on wooden structures of the above-mentioned objects “in situ” was verified by means of simulation models, which presented their initial and current technical conditions in relation to the type and amount of impact they should safely absorb. Moreover, within the framework of this paper, artificial intelligence methods have been implemented to predict the biological corrosion of the structures studied. The aim of the paper was to draw attention to the timber already built into buildings, which may constitute waste even after several years of operation, requiring disposal and at the same time the production of a substitute. The purpose of the research carried out by the authors of the article was to examine the older and newer buildings in use, the structures of which, in whole or in part, were made of wood. On a global scale, there will be considerable demand for the energy required to thermally dispose of this waste or to deposit it in landfills with very limited capacity until its complete biological decomposition. These energy demands and greenhouse gas emissions can be prevented by effective diagnostics of such structures and the predictability of their behaviour over time, with respect to the conditions under which they are operated. The authors of the article, during each assessment of the technical condition of a building containing wooden elements, analysed the condition of their protection each time and predicted the period of their safe life without the need for additional reinforcements or replacement by others. As the later reality shows, it is a very effective method of saving money and energy.

Energy Effectiveness or Economic Profitability? A Case Study of Thermal Modernization of a School Building

Thermal refurbishment of buildings results in certain energy, financial, and environmental effects. Such investments are financially supported in Poland after meeting the legally defined conditions of thermal protection and energy consumption. This paper presents a complex thermal modernization of a school building, performed by following Polish regulations. A detailed description of the studied object was given, and the calculation procedure was described. Then an optimal variant of an investment and an ex-post analysis were described. Simple payback time (SPBT) of modernization measures was from 15.8 years (insulation of the ceiling under the unheated attic) to 87 years for insulation of the wooden external wall, with 35.6 years for the whole project, which is shorter than the predicted lifespan of the whole building (50–70 years). Annual calculated heating demand decreased from 464.78 to 168.73 GJ, resulting in the primary energy consumption indicator (EP) of 484.44 and 129.46 kWh/m2, respectively. Thermal refurbishment with the replacement of an old boiler into a new wood-pellet one resulted in a significant reduction of SO2 and dust emissions from 451 to 27.5 kg and from 399 to 13 kg, respectively.

Improving the Energy Performance of Public Buildings Equipped with Individual Gas Boilers Due to Thermal Retrofitting

The article assesses an impact of thermal retrofitting on an improvement of the energy quality of public buildings in terms of their heating. The analysis covered a group of 14 buildings, including schools, kindergartens or offices, while energy audits were carried out for 12 of them. The indications of individual gas meters were the source of actual data for the assessment of changes in energy consumption indexes in operating conditions. The analysis showed a clear improvement in the energy quality of buildings; however, the actual effects were much lower than forecasted. The average forecasted decrease in energy consumption was supposed to be 64.3%, but the measured data showed only 37.1%. The investigation confirmed that the most complex refurbishing provided the most satisfactory decrease in energy consumption (51.4% of real decrease in energy consumption), while objects with partial thermal refurbishing reached an efficiency of only 21.8%. It was stated that in operating conditions, special attention should be paid to the manner of energy use, since different indicators of energy consumption can be obtained with the same parameters of building’s balance cover. The results obtained can be further utilized in thermal-refurbishment implementation procedures. Follow-up investigations on the impact of selected parameters on energy consumption are planned.

How Pro-Environmental Legal Regulations Affect the Design Process and Management of Multi-Family Residential Buildings in Poland

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.

Influence of Thermal Retrofitting on Annual Energy Demand for Heating in Multi-Family Buildings

The paper presented the analysis of heat consumption for heating in multi-family residential buildings before and after thermal retrofitting. The analysis involved four groups of buildings, i.e., 43 buildings in total, located in various localities, belonging to one weather station. The predicted level of energy savings resulting from thermal retrofitting was achieved from the energy audits. The actual heat consumption, following the calculation into so-called external standard conditions, was obtained based on the readouts from heat-meters. For each building, the values of heat consumption over the periods of 6–10 years were read. The performance measurements involved the periods before, during, and after thermal retrofitting. The following statistical tests were used for data analysis: Wilcoxon–Mann–Whitney, Shapiro–Wilk, Bartlett, ANOVA, Kruskal–Wallis, Dunn and Holm post-hoc. The performed analyses showed that the mean value of energy savings predicted by audits reached 38.5% when the real mean value of savings, achieved from heat-meters, equaled 30.3%. The annual energy demand factors for heating were calculated for final energy and non-renewable primary energy factors. It was established that most of the analyzed objects fulfilled the primary energy factor requirements found in the Polish technical and construction regulations, which were valid at the time of investment.