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• Thermal discomfort in a log house was assessed using a calibrated model. • Effective passive overheating prevention actions were identified for future climate. • Natural ventilation was the best-performing measure in reducing future overheating. • Building-related measures are of secondary importance under free-run operation. • Possibilities for future-proofing log houses are presented. This study aimed to identify the most effective passive design measures to prevent overheating in a log house in a temperate climate. The study was conducted with a calibrated thermal model under a future climate projection (SRES A2 scenario) utilising an EN 16798–1 adaptive comfort model for the building operated under free-run mode during summer. The effects of six building-related and three organisational measures on the projected future thermal comfort in the studied log house were evaluated. During 2011–2040 and 2041–2070, thermal insulation and thermal mass paired with natural ventilation with or without shading were among the best-performing combinations. During 2071–2100, three of the six best-performing combinations were thermal insulation and thermal mass paired with natural ventilation with or without shading. Comparing the first and the last periods, the most effective organisational measure reduced the operative temperature by an average of 0.35 or 0.34 °C in the first two periods and by 0.36 or 0.33 °C in the third period. By outlining the potential effectiveness of specific measures in preventing overheating discomfort under climate change conditions, the findings significantly contribute to climate change adaptation of log houses and buildings in general. These findings can be used as design guidelines for future buildings and to formulate future building regulations as well as a decision-making support for policy-makers. [ABSTRACT FROM AUTHOR]

Highlights • Thermal response of roof/wall was analysed by altering U value and solar properties. • Solar absorptivity has significant effect on total energy use, especially at U > 0.3. • Optimal total energy use in Hamburg and Granada was always achieved by cool coating. • Coating's solar properties affect indoor thermal comfort in summer and winter. Abstract In recent decades, high level of urbanization, air pollution and climate change have caused a frequent occurrence of urban heat islands, resulting in thermal discomfort and increased energy use of buildings. As a response, a lot of attention has been paid to building envelope characteristics, with an increasing number of studies investigating building envelope solar properties as one of the important factors affecting thermal performance. However, different climate characteristics are the reason why solar properties may have different efficiency at various locations, also because in cold or temperate climates building envelope has to be more thermally insulated, namely having lower thermal transmittance. Therefore, within this study, building energy use and indoor thermal conditions were analysed for an office cell using different types of solar absorptivity (e.g. white, dark grey, collector or cool coating) and thermal transmittance, on either external wall or roof. The analysis was conducted for hot-arid and temperate climate locations. The results showed that solar absorptivity can have a significant effect on total energy use, especially in cases with higher envelope thermal transmittance. It also showed that the application of cool coatings is more reasonable if the external building envelope is not intensively thermally insulated (e.g. in hot-arid climate). In general, the optimal total energy use in both analysed climates was always achieved by implementing cool coatings. Furthermore, the results showed that white and cool coatings have comparable external (20–30 K above T air in summer) and internal surface temperature responses, while dark grey coatings cause the surface to heat up significantly (external surface 60 K above T air in summer). [ABSTRACT FROM AUTHOR]

In recent years the use of wood based products in building industry has expanded. Although lightweight timber constructions essentially decrease environmental impact of a building, their consequential low thermal mass can lead to overheating during summer. Therefore, the purpose of this paper was to investigate various examples of enhanced lightweight constructions from the thermal response point of view. Several improvements were investigated (e.g. clay boards, wood wool thermal insulation, Phase Change Materials, etc.) and compared with the performance of a conventional thermally insulated high mass wall. Finite element model was created and dynamic thermal performance of enhanced lightweight external walls was analysed in three different European locations: Helsinki (Finland), Vienna (Austria) and Madrid (Spain). Certain enhancements resulted in lower internal surface temperature of constructions up to 1 °C, depending on location. In addition, it was shown that in order to further improve thermal performance, application of high intensity ventilation is necessary, which additionally lowered the internal surface temperature up to 8 °C. It was shown that enhanced and naturally cooled lightweight constructions are more suitable for locations with milder summer temperatures (Northern, Central Europe), rather than for hot climates (Mediterranean). It was concluded that the application of lightweight constructions should be thoughtful in order to achieve adequate thermal response of buildings. However, in lightweight buildings the integration of materials characterised by high thermal mass, high thermal effusivity and low environmental impact should be encouraged. [ABSTRACT FROM AUTHOR]

In recent years, the construction industry has been comprehensively focusing on energy performance of buildings and on achieving higher standards of living comfort. One of the most sophisticated ways to attain both at the same time is (re)achieving building’s climate balance by using bioclimatic design. Therefore, the main goal of this paper was to present a bioclimatic potential prognosis and to show its application on an example of the Alpine-Adriatic region. The bioclimatic potential prognosis was made for 21 characteristic locations. For this purpose, bioclimatic chart plots were made using elementary weather data and additionally, the actually received solar irradiance was precisely considered at every location. The latter was shown to have a large influence on the analysis results. Furthermore, an evaluation of performed bioclimatic potential prognosis was made with simulations of a generic building model using Energy Plus. The generic building model was tested in five selected locations and the heating and cooling demand results were compared with the bioclimatic potential analysis. The results showed that the application of the presented method can indicate which passive solutions should be applied in building design at a specific location in order to facilitate smaller energy usage and consequential higher indoor comfort. In addition, the presented approach can be used in order to incorporate the latest or predicted climate data into bioclimatic potential analysis. The latter has a significant influence on the design of buildings of the future. [ABSTRACT FROM AUTHOR]

Quality of indoor environment as well as energy consumption in buildings are a growing concern in the context of overheating of buildings, as the EU legislation is primarily focused on heating season. The statistical data of EU have shown that there is already a large amount of buildings not comfortably cool during summer and the trend is increasing. Therefore, the main goal of this paper is to evaluate the influence of high intensity passive cooling as one of the passive solutions for overheating of buildings on the overall thermal response of building envelope systems. Specifically, a variety of multi-layer external walls during realistic summer time conditions of Central European climate were considered. For this purpose, a finite element method was used to simulate the non-stationary thermal response of several heavy weight and light weight external wall constructions. The results have shown that indoor air change intensity as well as internal heat gains have a significant impact on heat flow through the building envelope. Clear difference in thermal behaviour was detected between light weight and heavy weight envelope systems, as a consequence of different thermal mass and thermal insulation position. While the results of the conducted study represent guidelines to architects, designers, investors and other stakeholders in building industry, the growing popularity of light weight constructions, especially in residential buildings, dictates further research of building envelope configurations and passive cooling system impact on the thermal response of constructions. [ABSTRACT FROM AUTHOR]

• The impact of passive measures on heating and cooling was assessed using MLR. • A bioclimatic potential analysis is helpful for future-proofing of single-family homes. • The opaque envelope U-value was the most relevant for the total and heating energy use. • The window area was the most relevant for the cooling energy use in present and future. • The relevance diagrams of passive parameters for the energy use were introduced. In the early phases of building design, it is essential to quantify the relevance of passive design measures in order to assure the desired thermal performance of buildings throughout their lifespan. In the present research work, the authors investigated the relevance of the selected passive design measures for heating and cooling energy use of single-family detached buildings at five European locations. To this end, a multiple linear regression analysis was performed, and least-squares estimates were used to identify the most relevant passive design measures under current and three future periods. The statistical analysis showed that the importance of passive design measures would change under the projected global warming effects. In general, the most relevant for the heating energy use of the analysed building models is the opaque envelope U value. Besides effective shading, the most relevant parameter affecting the cooling energy use is the window-to-floor ratio. Furthermore, relevance diagrams for the influence of passive design parameters on the resulting energy use under the climate change scenario and specific U values of the opaque envelope were defined. Building designers and policymakers can use them as design-support tool to find appropriate ways of converting the number of unknowns in future climate into information for designers and decision-makers to assure low vulnerability of the built environment to global warming. [ABSTRACT FROM AUTHOR]

• Low energy use of single-family buildings can be assured solely by passive design. • Passive adaptation only partly counterbalances climate change effects on energy use. • Total energy use will decrease in cold and temperate and increase in warm climates. • The most effective long-term climate adaptation measure is applying smaller windows. • New buildings should be designed according to mid-term optima (2020/2050 period). The presented study aims to clarify the implications of passive design measures on heating and cooling energy use of single-family residential buildings under European representative climates. In order to address this matter, different values of thermal transmittance (opaque and transparent), window to floor ratio, window distribution, shape factor, diurnal heat storage capacity, external opaque surface solar absorptivity and natural ventilation cooling rates were combined in 496,800 building energy models, which were simulated at eight locations. Because buildings are in use for many decades, the energy use simulations were made considering the projected climate change up to the end of the 21st century. The results delivered a set of the most effective passive design measures for achieving low energy use in buildings regarding climate type and period. A lower window to floor ratio was identified as the most universally applicable design measure to counterbalance the projected effect of a warming climate. In contrast, other measures vary according to climate type and studied period. Furthermore, it was concluded that it is difficult to neutralise the projected climate change effects on buildings' energy use, even when applying the best performing combination of passive design measures. However, reasonably low energy use can still be assured solely by passive building design, especially in oceanic, warm, and some temperate climate locations. Therefore, the identified trends in energy use and passive design measures represent the foundation for strategies and guidelines aimed at future-proof energy-efficient buildings. [ABSTRACT FROM AUTHOR]

Most children in early childhood spend approximately one third of the day in kindergartens. Therefore, it is essential that their stay in an educational institution is comfortable and without adverse health effects. Statistical data over the last decade show that the amount of enrolled children in kindergartens has increased. The problem of overcrowded kindergartens is usually solved by changing the existing norms for class sizes, or with alternative spaces that do not serve the original purpose. According to EU Directives, kindergartens are among building facilities that have to be renovated. The purpose of the paper was to analyse sanitary-technical and hygienic conditions of the selected playrooms of kindergartens and to define measures. Real-state conditions were evaluated in 35 playrooms of 16 kindergartens in the Central Slovenian region. The main emphasis was on the used materials, their cleaning capability, room acoustics, natural daylight, safety and comfort issues, as well on their possible adverse health effects. The combination of observation, measurements and calculations of reverberation time, and comparison with regulation demands was carried out. In many playrooms sanitary-technical and hygienic conditions did not fulfil regulation demands. Irregularities are mainly related to improper installation of final coverings, to low parapet heights and total opening area of windows, poor hygienic conditions, and selection of materials that may present health risks. Calculated and measured reverberation times deviated from optimal values. [ABSTRACT FROM AUTHOR]