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[Display omitted] • A total of 95 papers systematically reviewed cool material as a mitigation strategy for urban heat island (UHI). • Based on the type of reflection and the spectral range, the analysis found 7 material technologies (UV–Vis-NIR). • Optical properties such as reflectance (ρ), absorptance (α), and emittance (ε) are key factors in cool materials design. • Technological setbacks constitute a key limitation to scale cool material technologies and low-cost alternatives. • DRC and super cool materials represent the most efficient innovations amongst current technologies. The challenging urban expansion represents a pressing need to implement climate mitigation strategies for the urban heat island (UHI) effects and significant threats to the environmental quality, energy consumption, and human health. Thus, this manuscript systematically evaluates 95 relevant studies through a robust evidence-based analysis centered on the latest advances in cool materials, their potential, technological innovation, and global trends. The results showed studies in 21 countries, 81 cities, and 16 climate zones, of which the majority belong to Humid subtropical climates (Csa) including 29 % of studies, Oceanic climates (Cfb) with 15 %, and Mediterranean climates (Cfa) with 13 %. Spectrophotometry analysis is used in 48 % of the studies, while the most studied technologies are the Daytime Radiative Cooling (DRC); 22 %, followed by Thermochromics (TC); 19 %, Cool-Colored (CC); 17 %, Phase Change Materials (PCM); 17 %, Retroreflectives (RR); 11 %, Light-colored (LC); 5 % and Fluorescents (FL); 5 %. Finally, DRC reported the highest cooling power of up to 136 W/m2, however, the latest developments advocate for climate-dependent dynamic modulation techniques of Super Cool Materials (SCM) with Passive Daytime Radiative Cooling (PDRC) attributes and engineered spectral properties to dissipate urban heat to outer space in different meteorological conditions and wavelengths levels of the atmospheric window (8–13 μm). [ABSTRACT FROM AUTHOR]

As the global population becomes more concentrated in urban environments, higher numbers of people will be exposed to urban air pollution. The environmental and human health benefits of green roofs are widely recognized. The aim of this paper is to promote green roofs as an effective passive technique for pollution mitigation and adaptation to climate change. During the heating season, the ambient concentrations of PM1, PM2.5, and PM10 were measured above a green roof and a reference roof on a school building, located in New Belgrade, the second-most populous municipality and business center of Serbia's largest city. The percent reduction of PM10, PM2.5 and PM1, in January 2020, above the green roof compared to the reference roof was 7%, 16.6%, and 17.6%, respectively. The results show that lightweight green roof improve air quality in terms of PM concentrations for all months considered. In this paper, correlation analysis and the use of Pearson's coefficient were used in the process of analysis to determine the relationship between PM10, PM2.5, PM1, and ambient parameters: relative humidity, ambient temperature, and wind speed. It was found that the statistical correlation expressed by the Pearson coefficient between all PM particles and wind speed was statistically significant in all observed months except September. Also, the degree of significance of the correlation between PM particles and humidity and temperature of ambient air varies by month. [ABSTRACT FROM AUTHOR]

• Design criteria for active solar technologies integration in the historic built environment to favor energy transition, cleaner energy production, and climate mitigation. • Comparison of international guidelines' recommendations, design and assessment criteria. • Common glossary for the integration of active solar technologies in cultural heritage. • Definition of clear and updated design criteria valid for traditional and innovative active solar systems. • Support to solar innovation for the development of ad hoc products that considered correct design criteria. The paper focuses on architectural integration of active solar technologies (photovoltaic and solar thermal systems) in the historic built environment. Interpreted and used as a building material in the envelope, they are able to positively support energy transition and to contribute to climate change mitigation without compromising the original typological-functional characteristics. Their integration is fostered by innovative architectural design, aesthetical appeal, flexibility, multi-functionality, cost reduction, and technological development. Moreover, they can enhance economic value, functionality, and human comfort of buildings. Despite these advantages, there is a social diffidence on their acceptability due to policy, design, technical, economic and information barriers. To overcome these issues, the paper aims at identifying shared design criteria for their integration in the historic built environment, through a detailed assessment of 44 international guidelines. The study develops a taxonomy of international recommendations on energy efficiency, microgeneration, and solar integration, missing in literature so far, by analysing and comparing recurring criteria and recommendations. Also, a glossary of the most important terms according to the aesthetic, technical, and energy integration levels is created. Thus, the research defines an innovative framework of reliable design criteria, and a shared vocabulary to promote active solar technologies integration in the historic built environment. [ABSTRACT FROM AUTHOR]

Strict energy performance requirements have reduced the building's operational energy use and related environmental impact in the past decades. Consequently, the embodied impacts of buildings gained importance, and hence focussing on the life cycle impacts has become essential to further reduce the environmental impact of buildings. Life cycle assessment (LCA) is an internationally accepted method used for this purpose. Current LCA studies of buildings typically look at their whole life cycle but ignore potential changes in operational energy use due to climate change. However, the latter is expected to influence the operational energy use of buildings to a significant extent. This paper aims to improve the assessment of the operational phase by including variations in the yearly operational energy use caused by climate change and expected changes in the electricity mix as a strategy for climate change mitigation. This adapted dynamic assessment method is used to assess a Belgian office building. The results indicate that a Representative Concentration Pathway (RCP) 8.5 climate change scenario causes a decrease of 18 % for the end use of gas for heating and an increase of 32.4 % for the electricity use for cooling and ventilation. For the case study, the reduction of the environmental impact due to the decrease in gas use compensates the impact increase due to the higher electricity use. An increase in environmental impact in future would however occur if both heating and cooling are provided by electricity. Furthermore, depending on the changes that will occur in the electricity mix, the global warming potential of the office building will change by −13 % for an electricity mix dominated by renewables and by + 10 % for one with mainly production by gas compared to the situation with the current mix. However, the inclusion of a more extended list of environmental indicators shows that the overall environmental impact will only reduce by 4 % or even increase by 7 % compared to the situation with the current mix. [ABSTRACT FROM AUTHOR]

• We attained significant energy reduction potentials by energy-efficient renovations. • Large-scale implementation of heat pumps decreased the total delivered energy. • Energy savings ranged from 2 to 9% in 2030, 2–14% in 2040, and 2–19% in 2050. • Energy efficient building stocks alleviated the need for increased energy capacity. • New constructions should follow low-energy-use standards. A geo-referenced building stock model was used to analyse the energy and climate performance of the Knowledge Axis in Trondheim, Norway, by 2050. Strategies for energy upgrades, construction of more energy-efficient new constructions, changes in heating technologies, and their implications in terms of energy savings and greenhouse gas (GHG) emissions associated with energy and materials are assessed through various scenarios. Thematic maps were used to display the development of the total floor area and energy use. Compared to the baseline scenario for the same year, the energy savings range from 2 to 9%, 2–14%, and 2–19% in 2030, 2040, and 2050, respectively. New passive house constructions combined with energy upgrades in renovation projects and the maximum use of heat pumps have the greatest energy-saving potential. Our results displayed a large variation in the total net GHG emissions as a result of the alternative emission factors. The total net GHG emissions are primarily affected by the energy savings (amplified by assuming fossil fuel as the marginal mix), electricity mix (Norwegian or European), and allocation chosen for the incinerated waste to feed the district heating system. [ABSTRACT FROM AUTHOR]

• Relative and absolute home retrofit targets are reviewed and discussed. • Retrofit depth is determined by policy targets or practical cost-effectiveness. • Research studies find feasible energy savings of around 60% maximum. • Neighbourhood is optimal spatial scale to large-scale deliver home energy retrofit. • Future retrofits to be phased instead of one-off, and less primacy of fabric first. Home energy retrofit has been a publicly-funded policy in many countries since the 1990s. Government motivations have spanned from combating energy poverty to climate action and sustainability. Given the ambition of public policy, this paper reviews the targets, spatial scales and metrics used to deliver and evaluate home energy retrofit. Large-scale retrofit projects do differ: by spatial area, by retrofit depth and in evaluation metrics (if used). This review surveys first, the quantities of homes and inhabitants in intermediate spatial scales used to plan retrofit programmes. Second, the optimal spatial scale and retrofit depth to deliver large-scale home retrofit. Third, the quantitative metrics to evaluate retrofits, and future trends in occupant-based metrics. Neighbourhood is found to be the optimal spatial scale for home energy retrofit. Deep retrofit is described as 60% energy savings that, in synergy with energy supply decarbonisation, promises to deliver 80% or higher emission reductions. Recent evidence shows a shifting primacy from fabric-first retrofit to decarbonisation of heat generation and occupant health and well-being. [ABSTRACT FROM AUTHOR]

• A new methodology for energy use and peak load forecasting is developed. • Forecast of total energy use show a decrease between 2 and 11 TWh towards 2050. • Indicators for evaluating the difference between energy forecasts and statistics. • Large differences in how well forecasts predicted energy use towards 2020. • Calibration of energy use models on multiple years may improve energy forecasts. Projections of future energy use in buildings are a crucial tool in the tracking and attainment of political targets for energy efficiency and climate gas mitigation. In this article, a new methodology for projecting both the final energy use and the peak power demand for the Norwegian building stock is presented. The novelty of the methodology is to combine a set of existing, previously documented models in a novel way that integrates building stock models, hourly energy demand load profiles, and energy system modelling. The result is a coherent long-term projection of both annual and hourly energy use for different energy carriers, presented here with four scenarios of final energy use. The results show an expected decrease in total energy use for the Norwegian building stock between −2 and −12 TWh towards 2050, corresponding to a −3% to −14% of the energy use in 2020. Models for projecting future energy use are helpful both to evaluate the potential effects of current policies and to help reveal the need for new or updated policies. However, to have the desired effect, the projections must be as realistic as possible and reflect the actual development in energy use in the building stock. This necessitates a methodology for evaluating historical long-term annual energy use projections to understand why some models succeed in predicting energy use development while others fail. In this article, a set of indicators for evaluating the calibration of different models are presented. The indicators evaluate the initial difference and the divergence in the annualised trend for energy use projection models, compared to statistical data. The indicators are used to compare selected historical energy use projections for the Norwegian building stock against energy use from statistics from 2000 to 2020. The comparison shows large differences between the different projections, where calibrated scenarios show energy savings that tend to be more optimistic in the reference projection but more conservative in the best case potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • High resolution data from a Dutch net zero energy neighborhood is analysed. • Most buildings are positive energy, emit less carbon than they offset. • Large occupant differences in energy demand are visible across the households. • Occupant preferences and weather conditions greatly influence thermal energy demand. • Due to the high thermal efficiency, there is a high risk for summer overheating. Decarbonizing the building stock is a central component of global climate change mitigation efforts. In practice, this decarbonization can be achieved by a variety of different measures, including improvements in building energy efficiency, electrification of energy demand to reduce reliance on fossil fuels, and installation of distributed (renewable) generation in conjunction with flexible storage. However, these large-scale, often disruptive changes to the built environment also raise a number of concerns, such as loss of occupant comfort exacerbated by climate change, and introduction of additional stressors on the distribution grid. In this paper, we demonstrate several conclusions using detailed sub-hourly data of two years (2019–2020) collected from 40 homes in a recently refurbished net-zero energy neighborhood in the Netherlands. This paper shows that, in renovation projects like the case study, net-zero energy balances should be considered on a neighborhood, rather than building level to minimize worst case planning by accounting for occupant influences and seasonal effects. Furthermore, the energy flexibility and climate resilience in the buildings seems to be rather limited, as a result of energy efficiency improvements. While helpful in climate change mitigation efforts, the large seasonal differences in energy demand and generation imply that this evolution is perhaps sub-optimal from the grid perspective. The results illustrate that all homes in the study were net-zero energy over the two year period, sometimes net positive by up to a factor of three. This led to considerable excess generation especially during the summer months. In addition, it was found that indoor air temperature sensors in a number of buildings showed overheating beyond guideline thermal comfort temperature of 25°C, showing potential thermal comfort and heat stress for vulnerable occupants. These results motivate energy storage or modifications of the installed heat pumps to leverage summer excess generation while reducing the impact of summer heat waves. These findings should enable the Netherlands and other countries aiming to fully decarbonize the building stock formulate better, future-proof policies. [ABSTRACT FROM AUTHOR]

[Display omitted] Sustainable Development Goal #7 calls for "access to affordable, reliable, sustainable and modern energy for all." Scientific evidence is growing that greenhouse-gas emissions have a noticeable effect on the earth's climate. Many purpose-built post-war social housing estates in Europe that form high-density residential-tower blocks, however, do not meet current stringent energy-efficiency standards. As a result, many of these structures are under threat of overheating and require careful planning to implement holistic energy subsidisation schemes. This article presents a setup of building energy performance framework that was developed according to the in-situ measurements of building-fabric thermal structure to asset robust energy performance evaluation and certification schemes in the residential sector. This empirical study examines social householders' electricity reliability in accordance with assessing overheating risk of housing stock in South-eastern Europe where the weather is subtropical (Csa) and partly semi-arid (Bsh). It also investigates the gap between as-designed and as-built energy performances. The findings for thermal anomalies resulted from air infiltration through the building fabric, and a lack of natural ventilation through living spaces and excessive heat gains through sizeable and glazed areas. On a typical hot summer day, the internal temperatures of the simulated condominiums remained high throughout the day and night, ranging from a minimum 28.5 °C to a maximum 36.5 °C. Insights from this empirical study improve the national energy network and subsidisation schemes in Europe. The energy policy and regulations would benefit from conceptual level analysis and planning prioritisation in accordance with the climate characteristics of each EU-27-member state. [ABSTRACT FROM AUTHOR]

In view of advancing global warming, climate change adaptation and mitigation measures for buildings are becoming increasingly important. The following article discusses the question of whether current urban planning principles still provide a suitable framework for this purpose. Therefore, the aim of this paper is to identify and quantify the main parameters of the urban planning framework regarding energy demand and energy generation of buildings. In a novel, holistic approach, passive design measures were evaluated in a joint analysis based on a case study in the city of Vienna (Austria) with respect to their impact on heating and cooling energy demand, overheating potential, daylight availability, and solar potential of new buildings. The results show that by improving the thermal insulation of the building envelope, the importance of a high compactness of the buildings to lower the heating energy demand is decreased. In addition, moderate compactness can help reduce the energy demand for space cooling and artificial lighting and increase the solar potential of the buildings. Accordingly, the results question the dogma of a high degree of compactness that still exists to some extent and indicate that changing climatic conditions also require new approaches in the urban planning process. [ABSTRACT FROM AUTHOR]