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In the face of a changing climate, a growing number of construction firms are adopting carbon reduction targets on individual projects and across their portfolios. In the wake of the Paris Agreement, some firms are seeking a means of aligning their targets with sectoral, national and international mitigation commitments. There are numerous ways by which such an alignment can be achieved, each requiring different assumptions. Using data from the UK construction industry, this paper reviews current company commitments and progress in carbon mitigation; analyses the unique challenges in aligning construction targets, and presents a series of possible sectoral decarbonisation trajectories. The results highlight the disparity between current company targets and the range of possible trajectories. It is clear that a cross-industry dialogue is urgently required to establish an appropriate response that delivers both a widely-accepted target trajectory and a plan for its delivery. This paper is intended to stimulate and support this necessary debate by illustrating the impact of different methodological assumptions and highlighting the critical features of an appropriate response. [ABSTRACT FROM AUTHOR]

The paper presents an energy simulation-based study to investigate the impacts of climate change on energy consumptions of an office building located in five different cities, United States. Annual energy consumption of a medium-size office building was predicted by building energy simulation software—EnergyPlus using TMY3 weather data and future climate data. In this study, we have used two sets of further climate data with different climate models including (1) Hadley Centre Coupled Model, version 3 (HadCM3), and (2) NCAR Community Earth System Model version 1 (CESM1) with the Community Atmosphere Model version 5 (CAM5). A morphing method was applied to downscale the monthly weather forecast to hourly forecast for use in building energy simulation for the two General Circulation Models (GCMs): HadCM3 and CESM1. Using the generated future weather files, HVAC operation related mitigation measures including adjustment of thermostat setpoints, reduced HVAC operation hours, reduced VAV box minimum flow setting, and mixed-mode ventilation were simulated to compare with ASHRAE Standard 90.1 baseline simulated using TMY3 weather data. Simulation results on predicted whole building, heating and cooling energy consumptions were examined. The paper highlighted the importance of efficiently operating mechanical systems in buildings to ensure a more sustainable future. [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]

[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]

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]

• Halocarbon emissions in the building sector is increasing. • Non-Annex parties become bigger emitter instead of Annex parties. • Building sector accounts for more than half of global HFCs emissions. • Data sufficiency is key barrier for policy making. • Building cooling demand increase will push further halocarbon emissions. Estimates of the non-CO 2 greenhouse gas (GHG) emissions contributed by the buildings sector are necessary to evaluate this sector's potential for climate change mitigation. As data is lacking on fluorinated gases (F-gases) and hydrofluorocarbon (HFC) emissions from the buildings sector, this study aimed to estimate these emissions. First, the share of total global GHG emissions represented by buildings-sector emissions was estimated. Then, the HFC emissions of the buildings sectors in several countries (USA, EU, Japan, and China) are compiled. Next, based on necessary assumptions, global buildings-sector HFC emissions were estimated. Finally, this paper discusses implications for policy-makers. [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]