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Since the non-image-forming (NIF) effect of daylight on the human circadian system is widely accepted, adequate exposure to daylight is now considered one of the elements of a healthy life. In urban environment, one of the prerequisites for adequately lit indoor spaces is the amount and quality of daylight reaching the window, which is highly dependent on the characteristics of the urban environment. The aim of the study was to determine whether there are correlations between urban density (i.e., distance between buildings, building height), façade surface characteristics (i.e., colour and Window-to-Wall Ratios – WWR) and NIF potential of daylight. The study was conducted on a parametric geometric model of a street canyon covering a wide range of characteristics. Simulation results were interpreted using the Relative Melanopic Efficacy coefficient and Sky View Factor. The results indicate that the colour of the opposite façade can substantially impact the resulting NIF potential, especially for orange-red or blue hues. The results of the study show that this influence for building heights between 3 and 8 storeys becomes significant when the width of the urban canyon is less than 25 m and becomes substantially smaller at WWRs above 30 %. • Parametric evaluation of daylight spectral composition and urban canyon properties. • Façade colour effect becomes significant at urban canyon height-to-width ratios ≥1. • NIF daylight potential in urban canyons is directly correlated to urban density. • Increasing the WWR reduces the impact of façade colour on NIF daylight potential. • Results underscore the importance of façade colour in urban design decisions. [ABSTRACT FROM AUTHOR]

Off-site construction can represent a potential solution for worldwide mass housing demand and has gained a lot of attention during the refugee crisis in Europe. In particular, modular construction is one of the most cost-effective off-site methods for various types of buildings. Its characteristics are cost -effectiveness, quality control and quick on-site assembly. The design challenge is to join the stated advantages with operational sustainability, which is susceptible to climate-determined and energy efficient design. Therefore, the purpose of this paper was to systematically evaluate energy and visual (daylight) efficiency of singular prefabricated modular unit. In order to emphasise the relevance of local climate, modular unit model was analysed at five different locations, monitoring cooling, heating and lighting energy use. Results showed similarities and differences between the analysed locations and implemented design measures. The conducted analysis included variation of orientation, window to wall ratio, window distribution, envelope thermal transmittance and glazing characteristics. Surprisingly, the results indicate substantial impact of artificial lighting on the total energy use. Therefore, emphasising a direct connection to the Spatial Daylight Autonomy ( sDA ) values of the modular units. With sDA values below 50%, lighting can represent up to half of the total energy use. [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]

Bioclimatic potential analysis is one of the starting points for bioclimatic building design. However, as climate changes are being brought into the spotlight, bioclimatic potential is being put into question as well, because traditionally used passive strategies at a specific location may no longer represent properly balanced approach. Therefore, the purpose of this paper was to systematically evaluate bioclimatic potential of the selected five locations. At these locations, bioclimatic potential was observed separately for each of the last five decades. In the second part, present and future energy performance of one bioclimatic and one non-bioclimatic real residential building was simulated. The results show that yearly balance between heating and cooling passive strategies changed through time in all the locations. For example, the use of overheating prevention strategies is becoming more significant than it used to be in the past. Specifically, the period of year when shading is needed to achieve thermal comfort increased by 2–7% points, depending on location. Energy performance analysis of the selected buildings showed that by 2050 both analysed buildings will become cooling dominated and that by 2050 the current design solutions in bioclimatic buildings will become irrelevant or at least extremely inefficient. In general, in temperate climate zone the prevailing bioclimatic strategies integrated in architecture focus on heating season. Therefore, bioclimatic strategies in a particular location must be re-evaluated in order to design new and retrofit existing energy efficient contemporary buildings with comfortable indoor thermal conditions. [ABSTRACT FROM AUTHOR]

Abstract: Building-management systems (BMSs) are becoming increasingly important as they are an efficient means to having buildings that consume less energy as well as for improving the indoor working and living environments. On the other hand, implementing automated control and monitoring systems in buildings is still relatively new, and one of the obstacles for their wider implementation is the ease of setting up the appropriate parameters for the controllers. During our work on an experimental controller for an indoor environment that is installed in an occupied office in the building of the Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia, it has become evident that a computer simulator of the system would be a welcome aid for the optimization of its functioning. In this paper we present a simulator application developed in a combined Matlab/Simulink and Dymola/Modelica environment. The simulator mirrors the functioning of the control system and the dynamics of the indoor environment, where the thermal model of the simulator was developed in the Dymola/Modelica environment, while the illuminance model was developed and parameterized as a black-box model on the basis of measurements in the Matlab environment. The simulator can emulate the response of conventional ON/OFF controllers as well as fuzzy controllers. The paper presents the design of the simulator with all of the key elements described. The underlying models for the thermal and illuminance control are also separately described. Finally, the performance of the simulator is presented for a selected day. [Copyright &y& Elsevier]

• 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]

Abstract: In the era of informational and technological breakthrough, the automatically controlled living and working environment is expected to become a commonly used service. This paper deals with dynamically controlled thermal and illumination responses of built environment in real-time conditions. The aim is to harmonize thermal and optical behaviour of a building by coordinating energy flows that pass through the transparent part of the envelope. For this purpose, a test chamber with an opening on the southern side was built. Changeable geometry of the opening is achieved by the automated external roller blind. A fuzzy control system enables the positioning of the shading device according to the desired indoor set points and the outdoor conditions. Through the experiments, the fuzzy controllers were tuned and gradually improved. Some sets of the experiments are presented here to illustrate the process. [Copyright &y& Elsevier]

Daylight is ever more recognised as a major synchroniser of circadian rhythms, linking us to the 24 h solar day. However, the time that urbanised humans spend outdoors has decreased substantially during the last century, which highlights the importance of appropriate indoor daylighting. Quality and quantity of daylight in indoor environments are primarily modulated by the characteristics of the building envelope. In this context, a combined in-situ experimental (Ljubljana, Slovenia) and simulation study of a cellular office model was executed in order to evaluate the impact of different glazing types and internal wall colours on the non-visual potential of daylight. In particular, the impact of seven glazing types and six different wall cover hues at three reflectance levels was determined. Among these, three glazing types and three wall colours of equal reflectance were further evaluated through diurnal simulations of the indoor luminous environment. Low-e glazing with high visual transmittance and blue coloured wall were indicated as combinations with the highest non-visual entrainment, while the opposite is true for the combination of bronze tinted solar protective glazing and orange walls. In general, a better non-visual environment can be achieved using materials characterised by higher spectrally neutral transmissivity or reflectance than with those characterised by spectrally non-neutral properties and of lower transmissivity or reflectance. • Low-e glazing and blue coloured wall combination have highest non-visual potential. • Bronze tinted glazing and orange walls have lowest non-visual potential. • If possible, high transmitting glazing is recommended for typical cellular offices. • Similar impact of wall reflection & window transmissivity on non-visual potential. • The highest melanopic illuminance was more than twice the value of the lowest. [ABSTRACT FROM AUTHOR]

Due to the profound impact that building sector has on the environment and consequently the sustainability of our society, the evaluation of environmental impacts through life cycle assessment (LCA) should become part of building design. The number of published environmental product declarations (EPDs) is growing, which indicates that they can become valuable tools for building designers to evaluate the environmental performance of construction works. We identified that in the current EPD scheme an important part is missing – the results interpretation. In order to evaluate the environmental performance of buildings or their components and elements, the designer is "forced" to conduct a comparative assertion on a population of alternatives. The paper explores the results interpretation of LCA data in the context of the EPD scheme for building products and presents a comparative assertion method, which could guide designers through the results interpretation step of LCA. The proposed soft comparative assertion method was tested on a sample of external wall assembly alternatives and the results show that it significantly simplifies the LCA results interpretation and enables straightforward decision making. However, the method is not yet a fully functional tool and should be upgraded in order to make the decision process more robust and less subjective. With this paper we wish to encourage further research on the described topic, which is vital in order to add credibility to the EPD scheme as an instrument for lowering the environmental impact of the building sector. • Evaluation of environmental impacts by LCA should become part of building design. • Comparative assertions required in order to evaluate LCA data from EPDs. • No guidelines for building designers at the LCA results interpretation step. • Presentation of comparative assertion method framework for building designers. • Developed method significantly simplifies the decision making process. [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]

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]

• Adaptive thermal comfort field study was conducted for subjects at a high metabolic rate. • About 92% and 68% students were found comfortable during autumn and winter season, respectively. • Accepted mean airspeed for male was higher than female (AVSm = 0.29 m/s; AVSf = 0.17 m/s) • Seasonal comfort temperature varied by more than 5°C. • Subjects are found to be more sensitive towards outdoor temperature fluctuations. An adaptive thermal comfort study was carried for assessing the thermal comfort requirements of students working in naturally ventilated (NV) university workshop building in the composite climate of India over two seasons (Autumn and Winter). 1332 complete surveys, 516 and 816 from autumn and winter season, respectively were collected and analyzed. A maximum of 70% of subjects were found voting comfortable when indoor temperature varied from 28°C to 32°C. During the autumn season, the mean comfort temperature was about 5°C higher than the winter season. Also, female subjects had about 1.5°C higher comfort temperature compared to male subjects. Further, an attempt has been made to present an adaptive model for university students engaged in activity corresponding to machine work. The results were also compared with international thermal comfort standards. The results showed that students are more sensitive towards the fluctuations of outdoor conditions compared to the subjects in office and residential buildings. Moreover, subjects have shown better thermal adaptability towards prevailing mild cold climatic conditions through behavioural and clothing adjustments. [ABSTRACT FROM AUTHOR]