• Energy Research

Abstract With the rise of awareness of health and well-being in cities, urban environmental analysis should expand from energy performance to new environmental quality-based considerations. The limited potential to annually evaluate outdoor thermal comfort, predominant among these considerations, has restricted the exploration of the interrelations between urban morphology and annual energy performance. This study aims to bridge this gap by capitalizing on the new capabilities of Eddy3D – a Grasshopper plugin which enables effective calculations of hourly microclimatic wind factors via OpenFOAM which in turn are used to generate annual outdoor thermal comfort plots. Using this method, a parametric study was conducted for different typology and density scenarios in three different hot climatic contexts in Israel. The automated analytical workflow evaluated a total of 60 design iterations for their energy balance, outdoor thermal comfort autonomy (OTCA) and self-shading levels using the shade index. The high correlation found here between the annual shade index and the OTCA, across all climatic contexts, shows the potential of the shade index to serve as an effective indicator, in these contexts, for comparative or optimization outdoor comfort studies. Further results are both the superiority of the courtyard typology in both energy and outdoor comfort studies, and the contrasting impact of higher density on the annual energy balance (lower performance) and outdoor thermal comfort (higher performance) in hot climates. The annual plots of both the energy balance and OTCA reveal various seasonal and monthly trends in the three different climatic zones which can lead to localized and seasonal urban design strategies.

Abstract With the rise of awareness of health and well-being in cities, urban environmental analysis should expand from energy performance to new environmental quality-based considerations. The limited potential to annually evaluate outdoor thermal comfort, predominant among these considerations, has restricted the exploration of the interrelations between urban morphology and annual energy performance. This study aims to bridge this gap by capitalizing on the new capabilities of Eddy3D – a Grasshopper plugin which enables effective calculations of hourly microclimatic wind factors via OpenFOAM which in turn are used to generate annual outdoor thermal comfort plots. Using this method, a parametric study was conducted for different typology and density scenarios in three different hot climatic contexts in Israel. The automated analytical workflow evaluated a total of 60 design iterations for their energy balance, outdoor thermal comfort autonomy (OTCA) and self-shading levels using the shade index. The high correlation found here between the annual shade index and the OTCA, across all climatic contexts, shows the potential of the shade index to serve as an effective indicator, in these contexts, for comparative or optimization outdoor comfort studies. Further results are both the superiority of the courtyard typology in both energy and outdoor comfort studies, and the contrasting impact of higher density on the annual energy balance (lower performance) and outdoor thermal comfort (higher performance) in hot climates. The annual plots of both the energy balance and OTCA reveal various seasonal and monthly trends in the three different climatic zones which can lead to localized and seasonal urban design strategies.

Abstract The regenerative approach to design goes beyond limiting the environmental impact of the built environment and towards the enrichment of the ecosystem, adaptation to climate change, and the improvement of human health. This concept is being applied to buildings through new standards such as the Living Building Challenge, yet examples of implementation of regenerative design at the urban scale are rare. While this is a promising direction for sustainable design, in theory new metrics, design tools and workflows need to be developed to translate regenerative design concepts into practice effectively. Among other factors, barriers to implementation remain rooted in the shortcomings of existing urban simulation tools to evaluate a wide range of performance metrics simultaneously. This paper thus proposes a prototype workflow to evaluate regenerative performance using existing evaluation tools in a single digital workflow. A series of existing and customised plugins, most of which are already in use and open source, were integrated into a multi-parametric workflow based on the Grasshopper visual programming tool. The workflow was tested on Malaga as a case study and incorporated key performance indicators related to outdoor human thermal comfort, biophilia, daylight performance, and energy use and production, based on data exchange and synergies across the different tools. These indicators were evaluated for present and future climate scenarios obtained from a weather generator. This paper demonstrates the potential of this workflow to receive visual feedback on various aspects of regenerative urban design, thus enabling designers to more effectively pursue an evidence-based urban design process.

Abstract The regenerative approach to design goes beyond limiting the environmental impact of the built environment and towards the enrichment of the ecosystem, adaptation to climate change, and the improvement of human health. This concept is being applied to buildings through new standards such as the Living Building Challenge, yet examples of implementation of regenerative design at the urban scale are rare. While this is a promising direction for sustainable design, in theory new metrics, design tools and workflows need to be developed to translate regenerative design concepts into practice effectively. Among other factors, barriers to implementation remain rooted in the shortcomings of existing urban simulation tools to evaluate a wide range of performance metrics simultaneously. This paper thus proposes a prototype workflow to evaluate regenerative performance using existing evaluation tools in a single digital workflow. A series of existing and customised plugins, most of which are already in use and open source, were integrated into a multi-parametric workflow based on the Grasshopper visual programming tool. The workflow was tested on Malaga as a case study and incorporated key performance indicators related to outdoor human thermal comfort, biophilia, daylight performance, and energy use and production, based on data exchange and synergies across the different tools. These indicators were evaluated for present and future climate scenarios obtained from a weather generator. This paper demonstrates the potential of this workflow to receive visual feedback on various aspects of regenerative urban design, thus enabling designers to more effectively pursue an evidence-based urban design process.

Abstract As research on the correlation between urban design and environmental performance is still lacking, the following long-standing question still stands – How far can we densify urban districts without sacrificing their energy balance and indoor environmental quality? This question served as the starting point for a parametric typological study conducted at the block scale in the context of Tel Aviv, with the overall aim of promoting performance driven design of Mediterranean urban environments. Dynamic input parameters included fenestration ratio, aspect ratios and floor area ratios of 5 different building typologies in both office and residential land uses. Environmental outputs included energy cooling loads, spatial daylight autonomy and the monthly average load match between energy demand and photovoltaic energy supply. The courtyard typology was found to achieve the best performance in terms of monthly Load Match, however mostly in residential uses of lower density. Although the high-rise typology offered the best daylight conditions, it recorded the worse performance in terms of energy balance and energy cooling demand. Results demonstrate the potential of a parametric typological workflow to effectively indicate the tradeoffs between single building and urban scale design considerations. This potential could be harnessed to assess the environmental feasibility of net zero energy typologies in Mediterranean climates and will be used for district energy studies as part of future work.

Abstract As research on the correlation between urban design and environmental performance is still lacking, the following long-standing question still stands – How far can we densify urban districts without sacrificing their energy balance and indoor environmental quality? This question served as the starting point for a parametric typological study conducted at the block scale in the context of Tel Aviv, with the overall aim of promoting performance driven design of Mediterranean urban environments. Dynamic input parameters included fenestration ratio, aspect ratios and floor area ratios of 5 different building typologies in both office and residential land uses. Environmental outputs included energy cooling loads, spatial daylight autonomy and the monthly average load match between energy demand and photovoltaic energy supply. The courtyard typology was found to achieve the best performance in terms of monthly Load Match, however mostly in residential uses of lower density. Although the high-rise typology offered the best daylight conditions, it recorded the worse performance in terms of energy balance and energy cooling demand. Results demonstrate the potential of a parametric typological workflow to effectively indicate the tradeoffs between single building and urban scale design considerations. This potential could be harnessed to assess the environmental feasibility of net zero energy typologies in Mediterranean climates and will be used for district energy studies as part of future work.

Abstract Despite the urgent global call for an energy transition and the promotion of health and well-being in cities, a holistic approach to evaluating the trade-offs between an urban energy balance and environmental quality considerations is lacking. This paper bridges this gap by introducing a Grasshopper digital workflow through which the impacts of a wide range of building and urban design parameters on both energy performance and environmental quality can be effectively evaluated. This workflow is tested here for both theoretical and site-specific urban test cases in the context of Tel Aviv. For these test cases, the performance metrics - energy load match, spatial daylight autonomy and universal thermal climate index - were calculated using EnergyPlus, Radiance and ENVI-met simulation engines for different block typologies and were then analyzed. The results showed that among the block typologies, the courtyard achieved the optimal combination across the tested environmental criteria, despite the daylight and energy generation penalty associated with self-shading in compact block typologies. This workflow highlights the performative tradeoffs between energy and environmental quality considerations and can thus help urban designers achieve not only a lower environmental impact but also regenerative and healthier design outcomes.

Abstract Despite the urgent global call for an energy transition and the promotion of health and well-being in cities, a holistic approach to evaluating the trade-offs between an urban energy balance and environmental quality considerations is lacking. This paper bridges this gap by introducing a Grasshopper digital workflow through which the impacts of a wide range of building and urban design parameters on both energy performance and environmental quality can be effectively evaluated. This workflow is tested here for both theoretical and site-specific urban test cases in the context of Tel Aviv. For these test cases, the performance metrics - energy load match, spatial daylight autonomy and universal thermal climate index - were calculated using EnergyPlus, Radiance and ENVI-met simulation engines for different block typologies and were then analyzed. The results showed that among the block typologies, the courtyard achieved the optimal combination across the tested environmental criteria, despite the daylight and energy generation penalty associated with self-shading in compact block typologies. This workflow highlights the performative tradeoffs between energy and environmental quality considerations and can thus help urban designers achieve not only a lower environmental impact but also regenerative and healthier design outcomes.

Abstract Despite the global call for a paradigm shift towards new environmentally conscious urban planning, little has changed in practice, especially in hot climatic regions. This paper helps bridge this gap by introducing an automated parametric workflow for performance driven urban design. The methodology was tested here in the climatic and urban Mediterranean context consists of a parametric typological analysis, automated through Grasshopper with a total of 1920 iterations. For each iteration the performative effects of both building (i.e. typology, window to wall ratio and glazing properties) and urban design parameters (i.e. distance between buildings, floor area ratio and the orientation) were evaluated for residential and office building uses. The performance metrics - monthly/hourly energy load match and spatial daylight autonomy - were calculated using Energyplus and Radiance, respectively, and recorded for each iteration. The main results indicate substantial performative differences between typologies under different design and density scenarios; the correlation between the shape factor and the energy load match index as well as the benefits of the courtyard typology in terms of energy balance, with its challenging daylight performance, were established. These results demonstrate the potential of this workflow to highlight the design trade-offs between form and environmental performance considerations by designers and thus provide a new way to bridge the performative gap between buildings and their urban surroundings. Its application should help designers and policy makers contextualize nearly zero energy block concepts as well as define new criteria and goals.