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The EU has set clear targets regarding energy conservation of buildings and heavily supports activities towards achieving these targets on a European scale. The Green Deal, renovation wave, Energy Performance of Buildings Directive (EPBD) and Energy Efficiency Directive (EED) are some examples of EU's actions. For more than a decade, Energy Performance Certificates provide detailed data about the current energy needs of a building/building unit as well as information about the building construction and systems. A Building Renovation Passport (BRP) has, on a European level lately, been conceived as a tool that can stimulate cost-effective renovation in the form of a long-term basis, step-by-step deep renovation roadmap following defined quality criteria, and outline energy renovation measures that will improve the energy performance of the building. A Digital Building Logbook (DBL) is another tool that can serve as an archive where all building information can be stored and continuously updated. In this way, a full record of the building history will be electronically available with data regarding construction plans and permits, maintenance and system replacement activities, energy and heat consumption and production, etc. Building Renovation Passports and the Digital Building Logbook are tools that can help in achieving energy efficiency in existing buildings and contribute to reaching the EU renovation wave goals. The objective of this report is to investigate how the current EPC schemes best make the link towards the BRP and the DBL to further incentivise and stimulate cost-effective deep energy renovations of buildings across Europe. Three surveys were carried out to collect relevant information about the current status of the EPC data records and to identify stakeholders' potential needs, perceptions, thoughts and expectations, regarding a future connection between the EPC and the BRP or DBL. These surveys were prepared in two forms: using an excel file format circulated via email, and through an online questionnaire. Their completion was carried out by 16 countries. Regarding the EPCs, the state or regional energy agencies are the owner of the EPC data records and make full use of them. Their current main usage is for statistical reasons in the majority of the countries and their access is publicly available in half of the responding countries. Many common data is stored in the EPC database which can be linked with other tools (half of the EPC databases are already linked with another source). Regarding the BRP, a review of existing European schemes showed that successful BRPs have combined the renovation advice with financial support, legal requirements and/or communication campaigns. An important factor of the BRP is that it should be issued by a qualified expert and should provide customised measures for the specific building together with the investment costs per renovation measure(s). The DBL analysis showed that it should provide access to building information and contribute to better decision-making for future interventions as well as operation, use and maintenance records. The building owner/user is proposed to have full access to the logbook and provide/input about energy bills and building plans/construction materials info. An important aspect is that every time the building undergoes intervention works, the DBL should be updated accordingly. The most important barrier is the lack of motivation to update the DBL contents followed by the absence of synergies and consistency with other tools. Another interesting finding is that both BRP and DBL should be fed automatically by EPC data without any user interference. There is a clear possible interconnection between EPC data and BRP and DBL future contents. In addition, BRP can be an instrument to increase the renovation rates and DBLs are necessary for the management of buildings' information. The linkage of EPC data and BRP and DBL can be strengthened by introducing BRP and DBL as voluntary schemes under national incentives and should be fully implemented once they have demonstrated acceptance by the stakeholders.

Electrically powered buses reduce CO$_{2}$ and noise emissions in urban areas and thus promote the trend towards more livable cities. Upon this reason, more and more cities are introducing their first electrified lines as pilot projects. However, no standardized technology has yet emerged, which is why statements on interactions between vehicle, operation and infrastructure in public transport are proving to be difficult to make. In order to be able to make statistically significant statements in this respect, a simulation model was developed that depicts the three subsystems vehicle, operation and infrastructure. On the basis of measurement data from the PRIMOVE research project in Mannheim, in which an urban bus line is operated with two electrically powered buses, the simulation model was validated and a data basis was laid for further investigations. As a result, simulation studies with more than 700 simulated operating days could be carried out, the results of which represent the input for the following statistical analysis. Based on this analysis, the interactions described above will be demonstrated in the design of the main technical parameters, the battery lifespan and the energy demand of electrical bus lines. Through the findings of these simulations, an optimized version of the already electrified bus line in Mannheim will then be presented. Finally, a novel design methodology for electrification based on a multi-objective optimization is introduced. All parameters of the system are variable in order to apply the presented methodology to other projects and thus underline the general validity of the work.

Spain has a high level of energy consumption and CO2 emissions in detached houses, being the lack of an adequate insulation level and efficient energy systems the main causes. The Spanish Government has been performing modifications on its Building Technical Code (BTC) to address this issue, following European Directives. An assessment of the development of the Spanish BTC from its first 2006 version has been conducted in this work. A standard Spanish detached house was placed in the different Spanish climatic zones, designed with the minimum requirements of the 2006 and 2013 BTCs, and was then analyzed using the software Cerma. The results show that energy demand is reduced and the energy rating is improved with the stricter requirements introduced in the 2013 BTC. Although energy demand and CO2 emissions vary significantly among the 13 different climatic zones studied, the BTC modifications allow to reach a minimum energy rating independently of the climatic zone where the house is located. Opaque enclosures and internal loads were found to be the main contributors to building-related emissions. Additionally, possible actions to improve energy rating in detached houses are evaluated, finding that a moderate insulation thickness increase and the installation of heat pumps allow to reach the highest energy rating, being the improvement more apparent in northern and central regions. The results of this work may be extrapolated to other countries with similar climatic conditions to the studied zones, providing guidelines to fulfill energy saving regulations, evaluate emission sources and improve building energy efficiency.

The hot summer of 2018 posed many challenges with regard to water shortages and yield losses, especially for agricultural production. These agricultural impacts might further pose consequent threats for the environment. In this paper, we deduce the impact of droughts on agricultural land management and on water quality owing to nitrate pollution. Using national statistics, we calculate a Germany-wide soil surface nitrogen budget for 2018 and deduce the additional N surplus owing to the dry weather conditions. Using a model farm approach, we compare fertilization practices and legal restrictions for arable and pig breeding farms. The results show that, nationwide, at least 464 kt of nitrogen were not transferred to plant biomass in 2018, which equals an additional average nitrogen surplus of 30 kg/ha. The surplus would even have amounted to 43 kg/ha, if farmers had continued their fertilization practice from preceding years, but German farmers applied 161 kt less nitrogen in 2018 than in the year before, presumably as a result of the new implications of the Nitrates Directive, and, especially on grassland, owing to the drought. As nitrogen surplus is regarded as an “agri-drinking water indicator” (ADWI), an increase of the surplus entails water pollution with nitrates. The examples of the model farms show that fertilization regimes with high shares of organic fertilizers produce higher nitrogen surpluses. Owing to the elevated concentrations on residual nitrogen in soils, the fertilization needs of crops in spring 2019 were less pronounced than in preceding years. Thus, the quantity of the continuously produced manure in livestock farms puts additional pressure on existing storage capacities. This may particularly be the case in the hot-spot regions of animal breeding in the north-west of Germany, where manure production, biogas plants, and manure imports are accumulating. The paper concludes that water shortages under climate change not only impact agricultural production and yields, but also place further challenges and threats to nutrient management and the environment. The paper discusses preventive and emergency management options for agriculture to support farmers in extremely dry and hot conditions.

Abstract. This study presents the development of tools for the sustainable thermal management of a shallow unconsolidated urban groundwater body in the city of Basel (Switzerland). The concept of the investigations is based on (1) a characterization of the present thermal state of the urban groundwater body, and (2) the evaluation of potential mitigation measures for the future thermal management of specific regions within the groundwater body. The investigations focus on thermal processes down-gradient of thermal groundwater use, effects of heated buildings in the subsurface as well as the thermal influence of river–groundwater interaction. Investigation methods include (1) short- and long-term data analysis, (2) high-resolution multilevel groundwater temperature monitoring, as well as (3) 3-D numerical groundwater flow and heat transport modeling and scenario development. The combination of these methods allows for the quantifying of the thermal influences on the investigated urban groundwater body, including the influences of thermal groundwater use and heated subsurface constructions. Subsequently, first implications for management strategies are discussed, including minimizing further groundwater temperature increase, targeting "potential natural" groundwater temperatures for specific aquifer regions and exploiting the thermal potential.

The united nations educational, scientific and cultural organization (UNESCO) considers the historic urban landscapes as the world heritages. Managing historic city centers and maintaining historic cores are the emerging challenges for sustainable urban planning. Today, the historic cores form an important part of the economic, social, environmental, and physical assets and capacities of contemporary cities, and play a strategic role in their development. One of the most important approaches to the development of central textures, especially in historical and cultural cities, is the sustainable urban regeneration approach, which encompasses all aspects of sustainability, such as the economic, social, cultural and environmental aspects. To maintain sustainability and regeneration of historic cores of cities, it is necessary to provide insight into the underlying characteristics of the local urbanization. Furthermore, the fundamental assets are to be investigated as indicators of sustainable regeneration and drivers of urban development. In the meantime, a variety of research and experience has taken place around the world, all of which has provided different criteria and indicators for the development of strategies for the historic cores of cities. The present study, through a meta-analytic and survey method, analyzing the experience and research reported in 139 theoretical and empirical papers in the last twenty years, seeks to provide a comprehensive conceptual model taking into account the criteria and indices of sustainable regeneration in historic cores of cities. The quality of the survey has been ensured using the preferred reporting items for systematic reviews and meta-analysis (PRISMA).

Nature-based solutions may actively reduce hydro-meteorological risks in urban areas as a part of climate change adaptation. However, the main reason for the increasing uptake of this type of solution is their many benefits for the local inhabitants, including recreational value. Previous studies on recreational value focus on studies of existing nature sites that are often much larger than what is considered as new NBS for flood adaptation studies in urban areas. We thus prioritized studies with smaller areas and nature types suitable for urban flood adaptation and divided them into four common nature types for urban flood adaptation: sustainable urban drainage systems, city parks, nature areas and rivers. We identified 23 primary valuation studies, including both stated and revealed preference studies, and derived two value transfer functions based on meta-regression analysis on existing areas. We investigated trends between values and variables and found that for the purpose of planning of new NBS the size of NBS and population density were determining factors of recreational value. For existing NBS the maximum travelling distance may be included as well. We find that existing state-of-the-art studies overestimate the recreational with more than a factor of 4 for NBS sizes below 5 ha. Our results are valid in a European context for nature-based solutions below 250 ha and can be applied across different NBS types and sizes.