1,721,636 research outputs found
Transparent Facade Constructions: A Comparison between Conventional Insulation Glass and Vacuum Glazing
No full text(no german version) In recent years, contemporary architectural design has been influenced by new technical opportunities offered by the glass industry. Large glass panels and even structurally active glass elements can be found in many recent building designs. Moreover, building envelopes in many cases include large glass panels. Needless to say, the use of glass as an envelope material comes with advantages and disadvantages, and a good architectural design has to consider these aspects. Advantages, amongst others, encompass the increased solar penetration and solar gains in the cold season, the increased daylight availability, and the "clean" appearance of buildings; Disadvantages include, amongst others, the overheating risk in summer, thermal discomfort as a result of radiant temperature asymmetries, and increased heat loss. The last two aspects are directly linked to the rather high heat flow through conventional glazing systems compared to well-insulated opaque building components. There are numerous examples of buildings, where prevailing performance problems can - in one way or the other - be linked to inadequate planning of the transparent building envelope. Generally speaking, the transparent parts of building envelopes can be distinguished in elements that are operable (windows, doors), and elements, which are fixed. The former are characterized by highly complex opening mechanisms and seals and thus rather high cost. The latter regularly are less complex, but their design needs to consider other aspects (durability, structural stability, etc.). This contribution illustrates the results of a number of numeric thermal bridge simulations focusing on transparent façade constructions with fixed glazing. Thereby, the key performance indicators of different construction scenarios are derived and compared. These indicators include thermal coupling coefficient, surface temperature, and condensation risk. The scenarios are based on typically applied transparent façade constructions, which are simulated with insulation glass and, alternatively, with vacuum glazing. As transparent constructions with fixed glazing regularly have higher life-time expectancies than openable windows (given the reduced complexity), such constructions might be promising in terms of vacuum glass application and a thus improved thermal building performance. Moreover, the reduced weight of vacuum glazing panels in comparison to highly-insulating double and triple glazing might allow for more efficient building construction (structural elements, etc). The present contribution illustrates the construction principle of different elements, the simulated scenarios, and the results of the simulation runs.In recent years, contemporary architectural design has been influenced by new technical opportunities offered by the glass industry. Large glass panels and even structurally active glass elements can be found in many recent building designs. Moreover, building envelopes in many cases include large glass panels. Needless to say, the use of glass as an envelope material comes with advantages and disadvantages, and a good architectural design has to consider these aspects. Advantages, amongst others, encompass the increased solar penetration and solar gains in the cold season, the increased daylight availability, and the "clean" appearance of buildings; Disadvantages include, amongst others, the overheating risk in summer, thermal discomfort as a result of radiant temperature asymmetries, and increased heat loss. The last two aspects are directly linked to the rather high heat flow through conventional glazing systems compared to well-insulated opaque building components. There are numerous examples of buildings, where prevailing performance problems can - in one way or the other - be linked to inadequate planning of the transparent building envelope. Generally speaking, the transparent parts of building envelopes can be distinguished in elements that are operable (windows, doors), and elements, which are fixed. The former are characterized by highly complex opening mechanisms and seals and thus rather high cost. The latter regularly are less complex, but their design needs to consider other aspects (durability, structural stability, etc.). This contribution illustrates the results of a number of numeric thermal bridge simulations focusing on transparent façade constructions with fixed glazing. Thereby, the key performance indicators of different construction scenarios are derived and compared. These indicators include thermal coupling coefficient, surface temperature, and condensation risk. The scenarios are based on typically applied transparent façade constructions, which are simulated with insulation glass and, alternatively, with vacuum glazing. As transparent constructions with fixed glazing regularly have higher life-time expectancies than openable windows (given the reduced complexity), such constructions might be promising in terms of vacuum glass application and a thus improved thermal building performance. Moreover, the reduced weight of vacuum glazing panels in comparison to highly-insulating double and triple glazing might allow for more efficient building construction (structural elements, etc). The present contribution illustrates the construction principle of different elements, the simulated scenarios, and the results of the simulation runs
Performance Enquiries Regarding Traditional and Contemporary Indonesian Architecture: A Holistic Approach
No full text(no german version) This contribution sheds light on recent research efforts that pertain to the built environment in Indonesia. Within the rich diversity of cultures in the Nusantara archipelago interesting examples can be found that illustrate the adaptation to the challenging environmental conditions. Through this research the possibilities for sophisticated solutions for future are investigated, focusing on the building performance. Architecture and planning tasks in Indonesia have to consider the following preconditions: (i) The prevailing hot and humid climate, which will be strongly influenced by the climate change in the future; (ii) the country´s geography, which consists of a number of wide-spread islands; (iii) the rich and diverse historical development, including a very diverse architectural heritage; (iv) the location within the "Pacific Ring of Fire", causing recurring natural disasters (e.g. volcano eruptions, earthquakes); (v) a currently ongoing rapid change in socioeconomic key data (economic growth rate, population growth, digitalization); (vi) a strong tendency to urbanization. Whereas these facts are known, as well as the need for energy efficient buildings, the level of knowledge about the performance of buildings in different regions of Indonesia is rather limited. Specifically, regional building traditions are often treated only in historical discourse. Thus, an interdisciplinary research effort that aims to examine Indonesian architecture in a comprehensive and holistic way has been undertaken in the past years, based on works dating back to 2005. In this paper we present parts of these efforts, namely (i) the assessment of a contemporary art museum in the city of Yogyakarta using monitored indoor conditions, and conception of potential future improvement; (ii) Further data collection efforts currently performed on a number of traditional residential buildings, (iii) a review of current, exemplary re-development efforts including the utilization and adaptation of traditional architectural concepts in Indonesia, and (iv) the details of the recently started incentive on interdisciplinary research on Indonesian architecture.This contribution sheds light on recent research efforts that pertain to the built environment in Indonesia. Within the rich diversity of cultures in the Nusantara archipelago interesting examples can be found that illustrate the adaptation to the challenging environmental conditions. Through this research the possibilities for sophisticated solutions for future are investigated, focusing on the building performance. Architecture and planning tasks in Indonesia have to consider the following preconditions: (i) The prevailing hot and humid climate, which will be strongly influenced by the climate change in the future; (ii) the country´s geography, which consists of a number of wide-spread islands; (iii) the rich and diverse historical development, including a very diverse architectural heritage; (iv) the location within the "Pacific Ring of Fire", causing recurring natural disasters (e.g. volcano eruptions, earthquakes); (v) a currently ongoing rapid change in socioeconomic key data (economic growth rate, population growth, digitalization); (vi) a strong tendency to urbanization. Whereas these facts are known, as well as the need for energy efficient buildings, the level of knowledge about the performance of buildings in different regions of Indonesia is rather limited. Specifically, regional building traditions are often treated only in historical discourse. Thus, an interdisciplinary research effort that aims to examine Indonesian architecture in a comprehensive and holistic way has been undertaken in the past years, based on works dating back to 2005. In this paper we present parts of these efforts, namely (i) the assessment of a contemporary art museum in the city of Yogyakarta using monitored indoor conditions, and conception of potential future improvement; (ii) Further data collection efforts currently performed on a number of traditional residential buildings, (iii) a review of current, exemplary re-development efforts including the utilization and adaptation of traditional architectural concepts in Indonesia, and (iv) the details of the recently started incentive on interdisciplinary research on Indonesian architecture
The Potential of Descriptive Building Specifications as an Alternative to Detailed Normative Calculations
No full text(no german version) Energy performance calculations are stipulated by law in most European countries. Thereby, different calculation schemes have been developed in the past years in different countries. The physical processes in buildings were simplified in terms of normative calculation routines in most of these schemes. A major idea behind these simplifications was to enable different stakeholders (practitioners, engineers, and architects) to issue energy certificates without being simulation experts. Moreover, the simplifications needed to be described thoroughly in corresponding guidelines to ensure and facilitate the comparability of the energy performance of different buildings. However, neither of these objectives can be considered to be fully met. Regarding the former, the normative calculation procedures increased in complexity in the past years, so that the issuing of energy certificates requires not only the stakeholder´s expertise but also a comprehensive knowledge of the standards that form the calculation method. Regarding the latter, recent research efforts revealed that many guidelines do not fully cover every aspect of the calculation procedures and the assumptions regarding required input data. Thus, the comparability of energy certificates has to be strongly questioned, as a number of relevant calculation parameters are dependent on the interpretation of the corresponding issuer.Given this background, alternative approaches to building performance evaluation would be of interest. Previous approaches by different researchers suggested so called prescriptive indicators, which can be derived by basic building data (for instance, geometry and thermal quality of the building envelope components). This contribution is based on this concept. In the framework of a master thesis, a number of prescriptive indicators were considered. These indicators were derived for a set of sample buildings. In a parallel effort, energy certificates (encompassing Key Performance Indicators KPIs) were calculated for the sample buildings. It is clear that the prescriptive indicators cannot act as a 1:1 replacement for KPIs in terms of a numeric value. However, their usefulness can be expressed by the relation of the prescriptive indicator and the corresponding KPIs of a building. Thus, the results of the described calculation efforts were ranked. Subsequently, the lists of buildings ranked by the different indicators were compared in order to identify prescriptive indicators, which result in the same or at least similar ranking as the normative key performance indicators. Within this contribution, the suggested prescriptive indicators, the sample buildings, and the results of the analysis are presented and discussed.Energy performance calculations are stipulated by law in most European countries. Thereby, different calculation schemes have been developed in the past years in different countries. The physical processes in buildings were simplified in terms of normative calculation routines in most of these schemes. A major idea behind these simplifications was to enable different stakeholders (practitioners, engineers, and architects) to issue energy certificates without being simulation experts. Moreover, the simplifications needed to be described thoroughly in corresponding guidelines to ensure and facilitate the comparability of the energy performance of different buildings. However, neither of these objectives can be considered to be fully met. Regarding the former, the normative calculation procedures increased in complexity in the past years, so that the issuing of energy certificates requires not only the stakeholder´s expertise but also a comprehensive knowledge of the standards that form the calculation method. Regarding the latter, recent research efforts revealed that many guidelines do not fully cover every aspect of the calculation procedures and the assumptions regarding required input data. Thus, the comparability of energy certificates has to be strongly questioned, as a number of relevant calculation parameters are dependent on the interpretation of the corresponding issuer.Given this background, alternative approaches to building performance evaluation would be of interest. Previous approaches by different researchers suggested so called prescriptive indicators, which can be derived by basic building data (for instance, geometry and thermal quality of the building envelope components). This contribution is based on this concept. In the framework of a master thesis, a number of prescriptive indicators were considered. These indicators were derived for a set of sample buildings. In a parallel effort, energy certificates (encompassing Key Performance Indicators KPIs) were calculated for the sample buildings. It is clear that the prescriptive indicators cannot act as a 1:1 replacement for KPIs in terms of a numeric value. However, their usefulness can be expressed by the relation of the prescriptive indicator and the corresponding KPIs of a building. Thus, the results of the described calculation efforts were ranked. Subsequently, the lists of buildings ranked by the different indicators were compared in order to identify prescriptive indicators, which result in the same or at least similar ranking as the normative key performance indicators. Within this contribution, the suggested prescriptive indicators, the sample buildings, and the results of the analysis are presented and discussed
Recent Progress in the EVA Project: Evaluation of Visionary Architectural Concepts
No full text(no german version) This contribution reports on the progress in the EVA project. This project was started in 2017 based on past experiences made in the framework of workshops and design studios at the University of Applied Arts in Vienna. Within these workshops different concepts toward energy-active and reactive architectural concepts was conceived and realized into scale models. The major design goal was to provide a built structure that is not only energy efficient, but also comfortable for occupants, and can display dynamic behavior in response to stimuli from the surroundings and the occupants. To construct the designs into scale models, different supportive tools and techniques were deployed, such as numeric thermal building simulation, parametric design programming, electronic control loops and mechatronic systems. Moreover, the different designs and concepts were inspired by a wide range of ressources, such as biology, bionics, natural phenomena, and traditional architectural concepts. Partly, these concepts (e.g. the photosynthesis of algae plants) were integrated in the scale models. As such, the workshops and design studios could be considered a success. New, challenging, and exciting designs were developed, and engineered in terms of scale models. However, the proof of concept in terms of real life implementation is missing. This gap will be bridged by the EVA project, which targets the evaluation of different concepts and the realization of the most promising project as a fully functional full scale mock-up. Needless to say, the level of complexity increases by the scale: Aspects of structural and dynamic stability have to be considered, mechatronic elements have to be constructed, and intelligent and reliable building control modi have to be implemented.This paper describes the first phase of this project, which is the collection, description, and structured evaluation of a number of design studies from the past years. Thereby, it was decided not only to assess projects that were designed in the framework of the University of Applied Arts, but to investigate similar design studies from professional and academic backgrounds worldwide The contribution concludes with an outlook of the project´s next steps.This contribution reports on the progress in the EVA project. This project was started in 2017 based on past experiences made in the framework of workshops and design studios at the University of Applied Arts in Vienna. Within these workshops different concepts toward energy-active and reactive architectural concepts was conceived and realized into scale models. The major design goal was to provide a built structure that is not only energy efficient, but also comfortable for occupants, and can display dynamic behavior in response to stimuli from the surroundings and the occupants. To construct the designs into scale models, different supportive tools and techniques were deployed, such as numeric thermal building simulation, parametric design programming, electronic control loops and mechatronic systems. Moreover, the different designs and concepts were inspired by a wide range of ressources, such as biology, bionics, natural phenomena, and traditional architectural concepts. Partly, these concepts (e.g. the photosynthesis of algae plants) were integrated in the scale models. As such, the workshops and design studios could be considered a success. New, challenging, and exciting designs were developed, and engineered in terms of scale models. However, the proof of concept in terms of real life implementation is missing. This gap will be bridged by the EVA project, which targets the evaluation of different concepts and the realization of the most promising project as a fully functional full scale mock-up. Needless to say, the level of complexity increases by the scale: Aspects of structural and dynamic stability have to be considered, mechatronic elements have to be constructed, and intelligent and reliable building control modi have to be implemented.This paper describes the first phase of this project, which is the collection, description, and structured evaluation of a number of design studies from the past years. Thereby, it was decided not only to assess projects that were designed in the framework of the University of Applied Arts, but to investigate similar design studies from professional and academic backgrounds worldwide The contribution concludes with an outlook of the project´s next steps
Analyzing the Relation between Input Data and Key Performance Indicators for Building Energy Certificates: An Approach Using Algorithmic Modeling
No full text(no german version) This contribution concerns the reproducibility of energy certificates. To examine the impact of different input data assumptions on the results of energy certificates, sensitivity analysis was performed. Conducting such sensitivity analysis manually is not only time consuming and error-prone, but is also typically limited in view of input-data/result combinations. This can be a problem, as a number of input data combinations can have contradictory influences on corresponding KPI (key performance indicator) results. For instance, transparent building components increase not only solar gains, but also transmittance losses. As an alternative to manual modification of input data, the parametric algorithm-editor, Grasshopper (an Add-on to the CAD/CAM-environment Rhino) was utilized. The calculation standards of the Austrian energy certificate procedure were implemented in this environment. Input data values can be modified via a graphical user interface (rulers), and the impact of the change is instantly generated by the environment. Past research regarding planners' usage of energy certificate tools identified usability and overall user acceptance of such calculation tools as a weak spot. Thus, the implementation of calculation routines within a widely used drafting/parametrization tool could result in increased acceptance by planners. In a first methodological approach, the impact of input assumptions regarding building typology and window properties on solar gains, transmittance losses, and heating demand were considered. The contribution illustrates the method and the results of a number of case studies, which show that the concept can be usefully deployed in energy evaluation of buildings. Thereby, the approach can accommodate two requirements: On the one hand, it can result in a tool to evaluate building concepts in early design stages. On the other hand, it can serve as a conceptual vehicle to explore and evaluate calculation methods, such as the standardized energy certification procedure.This contribution concerns the reproducibility of energy certificates. To examine the impact of different input data assumptions on the results of energy certificates, sensitivity analysis was performed. Conducting such sensitivity analysis manually is not only time consuming and error-prone, but is also typically limited in view of input-data/result combinations. This can be a problem, as a number of input data combinations can have contradictory influences on corresponding KPI (key performance indicator) results. For instance, transparent building components increase not only solar gains, but also transmittance losses. As an alternative to manual modification of input data, the parametric algorithm-editor, Grasshopper (an Add-on to the CAD/CAM-environment Rhino) was utilized. The calculation standards of the Austrian energy certificate procedure were implemented in this environment. Input data values can be modified via a graphical user interface (rulers), and the impact of the change is instantly generated by the environment. Past research regarding planners' usage of energy certificate tools identified usability and overall user acceptance of such calculation tools as a weak spot. Thus, the implementation of calculation routines within a widely used drafting/parametrization tool could result in increased acceptance by planners. In a first methodological approach, the impact of input assumptions regarding building typology and window properties on solar gains, transmittance losses, and heating demand were considered. The contribution illustrates the method and the results of a number of case studies, which show that the concept can be usefully deployed in energy evaluation of buildings. Thereby, the approach can accommodate two requirements: On the one hand, it can result in a tool to evaluate building concepts in early design stages. On the other hand, it can serve as a conceptual vehicle to explore and evaluate calculation methods, such as the standardized energy certification procedure
The Application Potential of Vacuum Glazing in Building's Thermal Retrofit: A Case Study
No full text(no german version) Vacuum glazing is considered as a viable alternative for improvement of transparent components of the building envelope in the course of thermal building retrofit. Research and development efforts in the past decades focused on the vacuum glazing itself. Thereby, research targeted the development of durable edge sealing and selecting suitable materials for spacers in the vacuum between the two glass panes. However, the availability of durable vacuum glass is only the first step toward energy-saving transparent building components. The next step is to think about window constructions that consider the specific requirements of vacuum glazing. While new windows can be constructed from scratch to meet these requirements, this does not apply to the windows of existing buildings. Thus, the impact of vacuum glazing in existing window constructions has to be thoroughly evaluated. This contribution describes the method and results of a case study that focused on the implementation of vacuum glass in a number of window frames typical to the building stock in Central Europe. To assess the thermal performance of such assemblies, numeric thermal bridge simulation was deployed. Based on the results of a number of implementation scenarios, key performance indicators for building details as well as for overall building energy performance were derived. Subsequently, the results were utilized in simple economic calculations to explore the overall sustainability of such window retrofit measures.Vacuum glazing is considered as a viable alternative for improvement of transparent components of the building envelope in the course of thermal building retrofit. Research and development efforts in the past decades focused on the vacuum glazing itself. Thereby, research targeted the development of durable edge sealing and selecting suitable materials for spacers in the vacuum between the two glass panes. However, the availability of durable vacuum glass is only the first step toward energy-saving transparent building components. The next step is to think about window constructions that consider the specific requirements of vacuum glazing. While new windows can be constructed from scratch to meet these requirements, this does not apply to the windows of existing buildings. Thus, the impact of vacuum glazing in existing window constructions has to be thoroughly evaluated. This contribution describes the method and results of a case study that focused on the implementation of vacuum glass in a number of window frames typical to the building stock in Central Europe. To assess the thermal performance of such assemblies, numeric thermal bridge simulation was deployed. Based on the results of a number of implementation scenarios, key performance indicators for building details as well as for overall building energy performance were derived. Subsequently, the results were utilized in simple economic calculations to explore the overall sustainability of such window retrofit measures
Numeric Thermal Bridge Simulation and Building Information Modelling: A Structured Coupling Approach
No full text(no german version) This contribution illustrates recent development efforts for a better data interlinking between Building Information Modelling tools and numeric thermal bridge simulation applications. As widely recognized within the professional and research communities working in the fields of building informatics and building physics, the desired seamless data interchange between modelling and assessment tools with regard to relevant data on buildings, building components, and details. Moreover, this attractive possibility is hampered from a multitude of obstacles, which are related to different modelling techniques, missing input data, uncertainties regarding the full understanding of data interchange formats by all involved tools, etc. Progress regarding such data interchange has to be made in small and well-documented steps, so that potential end-users (architects, engineers, consultants) can benefit from the developments. Toward this end, we present recent implementation work within a state-of-the-art commercially available numeric thermal bridge simulation tool. Building information models based on the IFC-format can now be read within this tool. The present contribution illustrates the workflow, the benefit, and the limitations of the recent implementation, and delivers a proof of concept for this approach.This contribution illustrates recent development efforts for a better data interlinking between Building Information Modelling tools and numeric thermal bridge simulation applications. As widely recognized within the professional and research communities working in the fields of building informatics and building physics, the desired seamless data interchange between modelling and assessment tools with regard to relevant data on buildings, building components, and details. Moreover, this attractive possibility is hampered from a multitude of obstacles, which are related to different modelling techniques, missing input data, uncertainties regarding the full understanding of data interchange formats by all involved tools, etc. Progress regarding such data interchange has to be made in small and well-documented steps, so that potential end-users (architects, engineers, consultants) can benefit from the developments. Toward this end, we present recent implementation work within a state-of-the-art commercially available numeric thermal bridge simulation tool. Building information models based on the IFC-format can now be read within this tool. The present contribution illustrates the workflow, the benefit, and the limitations of the recent implementation, and delivers a proof of concept for this approach
Investigation of Historical Villa Architecture under Combined Consideration of Cultural and Performance-Based Aspects
No full text(no german version) Recent discussions about building´s energy performance of the building stock often emphasize the poor thermal quality of existing buildings. At the same time, it is often forgotten that different historic building traditions since Roman Antiquity did address building performance based on low-energy design features. While such design features, which regularly were based on evolutionary climatic adaptation pressure, are frequently promoted for building traditions of hot-and-dry and hot-and-humid climates, relatively little attention is being paid to such design features in moderate climates, e.g. in central Europe. Moreover, the architectural discourse on historic objects that are considered as lighthouse projects does regularly neglect performance aspects. In this context, the present contribution focuses on a number of rural and sub-urban Villa projects of the past 2000 years. These projects were widely examined concerning their architectural meaningfulness in terms of the "Villa" concept. To further investigate their architectural quality, the projects are empirically evaluated regarding their utilization of different, "low-energy" measures for improving thermal performance and indoor climate, such as cross-ventilation and shading. Moreover, the designs are investigated with specific reference to their (micro-) climatic context, and a methodology for a future detailed examination is delineated.Recent discussions about building´s energy performance of the building stock often emphasize the poor thermal quality of existing buildings. At the same time, it is often forgotten that different historic building traditions since Roman Antiquity did address building performance based on low-energy design features. While such design features, which regularly were based on evolutionary climatic adaptation pressure, are frequently promoted for building traditions of hot-and-dry and hot-and-humid climates, relatively little attention is being paid to such design features in moderate climates, e.g. in central Europe. Moreover, the architectural discourse on historic objects that are considered as lighthouse projects does regularly neglect performance aspects. In this context, the present contribution focuses on a number of rural and sub-urban Villa projects of the past 2000 years. These projects were widely examined concerning their architectural meaningfulness in terms of the "Villa" concept. To further investigate their architectural quality, the projects are empirically evaluated regarding their utilization of different, "low-energy" measures for improving thermal performance and indoor climate, such as cross-ventilation and shading. Moreover, the designs are investigated with specific reference to their (micro-) climatic context, and a methodology for a future detailed examination is delineated
Thermal Performance of Konrad Frey's Prefabricated Low-cost Loft House - A Case Study of a pioneering instance of sustainable architecture
No full text(no german version) This contribution presents an ongoing research effort addressing the performance assessment of a number of buildings planned by the Austrian architect Konrad Frey, who is considered to be one of the pioneers of sustainable architecture in Austria. A number of his buildings, planned in the 1970s, consequently integrated principles of modern solar houses. Relevant key projects are subject of an on-going research project. Thereby numeric building simulation was deployed to assess the energy performance of the buildings. In this contribution, we present the intermediate results of a study that focused on one of his latest buildings, namely the prefabricated low-cost loft house. As opposed to architect´s rather complex early designs the loft house concept targeted inexpensive solutions and used simple and commonly available building components and systems. As part of the overall project, the thermal performance of this building was evaluated in terms of the effectiveness of passive cooling via various ventilation schemes (including night time ventilation).This contribution presents an ongoing research effort addressing the performance assessment of a number of buildings planned by the Austrian architect Konrad Frey, who is considered to be one of the pioneers of sustainable architecture in Austria. A number of his buildings, planned in the 1970s, consequently integrated principles of modern solar houses. Relevant key projects are subject of an on-going research project. Thereby numeric building simulation was deployed to assess the energy performance of the buildings. In this contribution, we present the intermediate results of a study that focused on one of his latest buildings, namely the prefabricated low-cost loft house. As opposed to architect´s rather complex early designs the loft house concept targeted inexpensive solutions and used simple and commonly available building components and systems. As part of the overall project, the thermal performance of this building was evaluated in terms of the effectiveness of passive cooling via various ventilation schemes (including night time ventilation)
Uncertainties in Building Energy Certification: Two case studies pertaining to zoning
No full text(no german version) Building energy certification is stipulated by law in the majority of the European countries. The intention of these regulations is to offer key performance indicators (KPIs) to relevant and interested stakeholders. Another motivation for implementing these calculation schemes was to compare the energy performance of different buildings. However, existing guidelines for building energy evaluation do not comprehensively outline the input data collection process and the derivation of substantial KPIs. Furthermore, practitioners do not share a common understanding of the approach to energy certificates, resulting in different practical methods and different interpretations of the calculation guidelines. As a result, the envisioned comparability between buildings is not ensured, as a number of studies illustrated in the past.This contribution focuses on a specific uncertainty in building energy evaluation input data, pertaining to zoning and usage assumptions. Toward this end, two case studies are presented. A number of existing buildings (typical Viennese building stock) were subjected to the Austrian normative energy certification calculation. Thereby, different scenarios regarding the zoning and usage profiles of the buildings were developed. On the one hand, the calculated performance of individual (residential) units was compared with the calculated performance of the whole building. On the other hand, calculations considering different usage assumptions in different zones within the building (detailed calculation) were compared to results based on generalized assumptions for the whole building. The evaluation of the case study buildings showed significant differences in KPIs, given different input data (depending on the case study, heating demand showed deviations up to 50%). The results emphasize the importance of a clear documentation of input data assumptions for building-related energy assessment.Building energy certification is stipulated by law in the majority of the European countries. The intention of these regulations is to offer key performance indicators (KPIs) to relevant and interested stakeholders. Another motivation for implementing these calculation schemes was to compare the energy performance of different buildings. However, existing guidelines for building energy evaluation do not comprehensively outline the input data collection process and the derivation of substantial KPIs. Furthermore, practitioners do not share a common understanding of the approach to energy certificates, resulting in different practical methods and different interpretations of the calculation guidelines. As a result, the envisioned comparability between buildings is not ensured, as a number of studies illustrated in the past.This contribution focuses on a specific uncertainty in building energy evaluation input data, pertaining to zoning and usage assumptions. Toward this end, two case studies are presented. A number of existing buildings (typical Viennese building stock) were subjected to the Austrian normative energy certification calculation. Thereby, different scenarios regarding the zoning and usage profiles of the buildings were developed. On the one hand, the calculated performance of individual (residential) units was compared with the calculated performance of the whole building. On the other hand, calculations considering different usage assumptions in different zones within the building (detailed calculation) were compared to results based on generalized assumptions for the whole building. The evaluation of the case study buildings showed significant differences in KPIs, given different input data (depending on the case study, heating demand showed deviations up to 50%). The results emphasize the importance of a clear documentation of input data assumptions for building-related energy assessment
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