Search

• 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]

• 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]

The paper provides an overview of a part of research related to the analysis of information technologies and measures for improving the energy efficiency in urban planning that can contribute to mitigating the impact of climate change. The first part of the paper deals with problems supported by the numerous data on negative effects of climate change on the cities, such as urban heat islands, energy and ecological crisis. The second part of the paper proposes solutions that rely on information technologies which facilitate process of urban planning. Two projects related to the implementation of measures for improving the energy efficiency in urban planning were conducted within this research. The first one is considering the design of a spa centre in an undeveloped mountain landscape and the second one is dealing with reconstruction of a residential block in urban built environment. In the first case study, the proposed solutions rely on the information technologies, while in the second case study they rely on the implementation of measures for improving the energy efficiency in urban planning. The results show that the application of different measures in urban planning depends on the level of the built environment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Presents time series of embodied emissions in UK construction from 1997 to 2011. [•] Contends that mitigation requires greater focus on material efficiency. [•] Identifies barriers to uptake of alternative materials, technologies and practices. [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]

Abstract: One of the cheapest ways to reduce CO2 emissions is thermal renovation of existing homes. Germany is a world leader in this project, with a strict building code, generous state subsidies, and an advanced renovation infrastructure. The effects of its policies are here explored in the light of progressive tightening of the building code, and the strict criteria for subsidies. Data on costs and outcomes of residential building renovations are presented from published reports on renovation projects, and cross-checked with projects investigated directly. Comparisons are made in terms of euros invested for every kilowatt hour of heating energy saved over the lifetime of the renovations, for standards ranging from 150kWh (the lowest standard) to 15kWh (the highest) of primary energy use per square metre of floor area per year. It is found that the lowest standard is an order of magnitude more cost-effective than the highest, in terms of both energy saved per euro invested, and return on investment over the lifetime of the renovations, regardless of fuel prices. It is argued that this throws into question Germany''s policy of progressively regulating for higher renovation standards, and offering subsidies only for projects that go beyond the minimum standard. [Copyright &y& Elsevier]

Abstract: In this study the life cycle primary energy use and carbon dioxide (CO2) emission of an eight-storey wood-framed apartment building are analyzed. All life cycle phases are included, including acquisition and processing of materials, on-site construction, building operation, demolition and materials disposal. The calculated primary energy use includes the entire energy system chains, and carbon flows are tracked including fossil fuel emissions, process emissions, carbon stocks in building materials, and avoided fossil emissions due to biofuel substitution. The results show that building operation uses the largest share of life cycle energy use, becoming increasingly dominant as the life span of the building increases. The type of heating system strongly influences the primary energy use and CO2 emission; a biomass-based system with cogeneration of district heat and electricity achieves low primary energy use and very low CO2 emissions. Using biomass residues from the wood products chain to substitute for fossil fuels significantly reduces net CO2 emission. Excluding household tap water and electricity, a negative life cycle net CO2 emission can be achieved due to the wood-based construction materials and biomass-based energy supply system. This study shows the importance of using a life cycle perspective when evaluating primary energy and climatic impacts of buildings. [Copyright &y& Elsevier]

• A trans -scalar analysis of architectural issues relating to passive solar heating through glazing. • A global estimation of the potential for passive solar heating in Europe. • A multi-criteria comparative analysis of the efficiency of different types of glazing. • An investigation of the carbon and energy payback times according to the properties of glazing. • An economic analysis using a novel method based on the levelized cost of energy. Glazing transparency provides buildings with valuable solar energy during periods of colder weather, thus contributing to the mitigation of climate change. However, this same transparency also leads to heat loss which can offset heat gains. Although the use of insulated glazing addresses this challenge by multiplying the number of glass panes, at the same time it reduces the solar factor and thus the heating potential. This article aims to estimate the potential for passive solar heating in Europe according to the energy performance of glazing. This potential is undoubtedly a valuable resource for sustainable architecture. However, an analysis based on regional weather conditions shows a wide disparity in the energy savings that can be expected from a south-facing facade. These savings are most often well below a building's average energy consumption and so a balance has to be found between the thermal resistance and the solar factor of glazing. In addition, the carbon footprint and cost of the most efficient glazing can considerably extend the environmental and economic payback time of a retrofit. This research shows that the potential for passive solar heating is significant but only as long as each architectural situation is analysed according to its specific context and function. This potential would be even greater if windows were designed and used as adjustable facade elements to suit variations in weather and use. [ABSTRACT FROM AUTHOR]

• A retrofit selection strategy employing economic and environmental decision criteria was proposed. • Building energy retrofits were evaluated through a life cycle thinking approach. • Retrofits with operational emissions savings may not be beneficial when considering life cycle impacts. • Energy mix and the heating system of the house greatly impact the effectiveness. • Retrofit selection changes with stakeholder priorities on environment and economics. Improving the energy performance of buildings has been a much-discussed topic over the past few decades. With the current focus on climate change mitigation, emissions reduction has also come to the forefront of this discussion. Retrofitting is an option to improve the energy and emissions performance of buildings. However, in the residential building stock, retrofit planning for existing buildings faces many complexities due to variations in climatic conditions and macro-environment as well as the presence of multiple stakeholder groups. Thus, in identifying solutions, it is necessary to take a holistic perspective that covers these different dimensions. In this paper, commonly used building energy retrofits were evaluated through a life cycle thinking approach. The performance of various retrofit options applicable for single family detached housing were evaluated using the HOT2000 energy simulation software package under the varying climatic conditions and energy supply scenarios across Canada. The retrofits were evaluated in terms of the additional investment, energy use and cost reduction achieved over the life cycle, and life cycle emissions reduction. The findings indicate that the provincial energy mix and the heating system of the house (i.e. electric or natural gas) play a major role in determining the effectiveness of a retrofit, and this "effectiveness" changes at different stakeholder levels. However, not all retrofits that reduce emissions make economic sense and vice versa when life cycle thinking comes into play. The findings will be useful for building owners and occupants as well as for policy developers and other decision makers interested in demand side management. [ABSTRACT FROM AUTHOR]

• Energy renovation has a central role in the Croatian plan of climate change mitigation. • Almost 600 buildings with 16,400 apartments were renovated in Croatia in four years. • Renovations induce 32 jobs in Croatian economy per 1 million EUR of investments. • Total economic effects are 3 times higher than initial direct effects of investments. • Energy renovation reduces energy import dependency of the Croatian economy. The aim of this paper is to gain new knowledge on contributions of energy renovation of multi apartment buildings to economy and climate changes. The research methodology is based on applying the input–output model, which enables the analysis of direct, indirect and induced effects. The analysis was conducted on the sample of the Republic of Croatia. The reference research period is from 2017 to 2020. The results obtained confirm the existence of indirect socioeconomic effects of energy recovery projects which were justified by being co-funded from national budgets or EU structural funds. The growth induced by gross value added and employment positively effects the revenue from taxes and contributions, and by co-financing energy renovations they do not disturb the stability of public finances. The energy renovation of multi apartment buildings increases the energy sufficiency of the domestic economy due to the fact that the need for imported energy decreases throughout the entire life of the investment. A decrease in import dependency decreases the sensitivity of the economy from possible negative effects of the disorder on the world market of energy products. The obtained results show positive effects of energy renovation of multi apartment buildings on climate changes, primarily through the decrease of the amount of energy consumption in an energy renovated area and the decrease of harmful particle emission (CO 2). [ABSTRACT FROM AUTHOR]

Urban overheating affects the energy, health, power, survivability and environmental quality of cities. We calculated the magnitude of overheating in Sydney, Australia, at close to 9 °C, which causes a cooling penalty of up to 16% and an increase in the indoor overheating levels of up to 56%. We developed and evaluated eight heat mitigation scenarios based on the use of reflective surfaces, additional greenery, an increase in the evapotranspiration rate and several combinations of these factors. We estimated that mitigation can decrease the peak ambient temperature by up to 2.9 °C, reduce the maximum annual cooling consumption by up to 1.5 TWh, decrease the CO2 emissions by as much as 1.21 MT CO 2 , reduce indoor overheating by up to 80%, decrease the heat-related morbidity by 1.07–1.49, and decrease the heat-related mortality anomaly by as much as 1.39 per 100,000 citizens. We estimated the associated water penalty range to be between 80 and 100 Gl/year or between 13 and 16.7% of the water consumption in Sydney. [ABSTRACT FROM AUTHOR]