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Urban built form and density are crucial parameters for the optimization of building energy performance. However, a cohesive framework which correlates building energy with urban built form and density is lacking, with no unified agreement on the concept of urban density. This study establishes the subtle interrelationships between urban built forms, density and building energy performance using two density indicators, specifically, site coverage and plot ratio. This paper initially considers geometrical variables of four customary urban built forms to investigate their relationship with the density indicators. Energy analyses are performed on the geometrical models representing residential buildings using the City of London as an example of a temperate climate. Annual building energy demands of pavilion, terrace, court and tunnel-court forms are calculated. The findings are used to produce a heat map of energy intensity on the Form Signature graphs. Results show that high-rise buildings with greater plan depths achieve higher energy efficiency. Moreover, it is shown that greater cut-off angles correspond to higher energy demands under temperate climatic conditions. An energy indicator, termed Energy Equity is introduced which represents the ratio between PV energy generation installed on roofs with respect to the total energy demand of the building. Further analyses show that by considering energy demand and PV energy generation simultaneously, low-rise buildings with greater plan depths provide improved energy performance. A comparative analysis of the energy performance of different built forms with similar geometric parameters demonstrates that the tunnel-court and the pavilion built forms provide the best and worst energy performance, respectively. However, when constraining density whilst changing other geometric parameters, this converse is true. Finally, the study illustrates that the same density for the same built form can be achieved by different combinat

This research uses empirical data and supplementary computer simulation result to study the summertime cooling effect of different landscape patterns in urban areas in China. It employs field monitoring to collect hourly air temperatures and relative humidity at pedestrian level over five consecutive days in July 2016, and calculates the discomfort index for each scenario in studied urban squares. It also builds simulation models using Citysim and Meteonorm software to further explore the cooling effects of different landscape patterns within the same square. The results from field research show that the difference in cooling and humidification amongst the four landscape patterns is significant, as is the thermal comfort or discomfort caused by such effect. The research finds that the urban square equipped with only hard paving and no canopy coverage could cause extreme discomfort and heatstroke during summertime in the studied climate, whereas the urban square with lawn grass, high canopy closure and thick canopy can reduce discomfort. The simulation analysis further confirm that lawn grass can noticeably reduce the ground surface temperature and the surface temperature of the surrounding buildings than if using asphalt as the ground cover. The findings from this research provide design guidance for the landscape configuration of urban squares in similar climates.

The building and transportation sectors are responsible for the greatest proportion of energy consumption in cities. While they are intrinsically interlinked with urban built form and density, climate change and technological innovation are having an effect on their relative contributions. This paper aims to develop an optimisation framework to facilitate the identification of the most energy-efficient urban built forms and urban geometry for the future built environment that can be adapted to the changing climate and ongoing technological development. It examines future scenarios for the city of London as a temperate climate zone (as a case study), in 2050, and contrasts it with the present situation. Specifically, the impact of climate change along with the penetration of electric vehicles into the transportation system that can be charged via rooftop photovoltaics is investigated. This study initially develops the geometrical models of four selected urban built forms and, secondly, analyzes their energy performance using an urban energy simulation software. The results, showing the impact of future scenarios on building energy performance, urban built form and density, demonstrate that court and tunnel-court built forms show better energy performance for future development. It is therefore recommended that for future urban developments in London, deep plan court and tunnel-court buildings with a lower number of storeys and a large cut-off angle are more advantageous in terms of building energy to accommodate the expected climate change. Finally, results of simulation trials indicate that the total building energy demand in 2050 is considerably higher than in the present climate as a result of additional cooling load and electric vehicle charging load.

Urban built form and density are crucial parameters for the optimization of building energy performance. However, a cohesive framework which correlates building energy with urban built form and density is lacking, with no unified agreement on the concept of urban density. This study establishes the subtle interrelationships between urban built forms, density and building energy performance using two density indicators, specifically, site coverage and plot ratio. This paper initially considers geometrical variables of four customary urban built forms to investigate their relationship with the density indicators. Energy analyses are performed on the geometrical models representing residential buildings using the City of London as an example of a temperate climate. Annual building energy demands of pavilion, terrace, court and tunnel-court forms are calculated. The findings are used to produce a heat map of energy intensity on the Form Signature graphs. Results show that high-rise buildings with greater plan depths achieve higher energy efficiency. Moreover, it is shown that greater cut-off angles correspond to higher energy demands under temperate climatic conditions. An energy indicator, termed Energy Equity is introduced which represents the ratio between PV energy generation installed on roofs with respect to the total energy demand of the building. Further analyses show that by considering energy demand and PV energy generation simultaneously, low-rise buildings with greater plan depths provide improved energy performance. A comparative analysis of the energy performance of different built forms with similar geometric parameters demonstrates that the tunnel-court and the pavilion built forms provide the best and worst energy performance, respectively. However, when constraining density whilst changing other geometric parameters, this converse is true. Finally, the study illustrates that the same density for the same built form can be achieved by different combinat

The paper introduces a novel indicator of urban built form termed Form Signature. Generic models of four urban built forms are developed, including pavilion, terrace, court and a newly introduced tunnel-court is used to compare and contrast their land-use performance and density characteristics. Selecting plot ratio and site coverage as the most popular and appropriate density indicators, the simultaneous relationship to each of the considered urban built forms is shown graphically with the number of storeys, plan depth and cut-off angle as the main variables of interest. For existing urban areas, the resulting graphs provide a robust tool for statistical analysis of contexts such as climate, economy, energy and crime potential and establish their relationship to form and density. To show the value of the contribution, analysing 32 case studies from 19 cities in different global locations showed an insignificant relationship between climate and form/density of urban areas, whilst practically depicting that urban areas built in court form acquire higher cut-off angle compared to terrace form urban developments. For planning the future urban areas, the resulting relationships provide application-oriented urban planning tool to facilitate the most effective land-use method in order to achieve sustainable cities. Examples showing the potential of the tool for future statistical energy and social analysis of urban areas are provided. Finally, a relative comparison shows that the newly-introduced tunnel-court form achieves the greatest density while pavilion achieves the lowest.

Cities are recognized as the main consumers of energy on the planet, and to optimize their energy consumption and enhance the potential of using renewable energy sources, built form and density are considered highly influential factors. The energy efficiency of compact built forms has been debated by many studies. Meanwhile, urban density, as an attribute of urban form, has yet to be well defined due to the diversity of density indicators used in literature. Hence, there is a lack of integrated guidelines for urban density indicators and their relationships with urban built forms in urban energy studies. This thesis establishes a framework to demonstrate the inter-correlation of urban built form, density and energy for residential buildings, and the impact of climate as an influential parameter is investigated by adopting a mixed methods research approach. It primarily identifies the relationship between the urban built form and density by introducing a novel indicator of urban form termed the Form Signature. It demonstrates the simultaneous correlation of two selected density indicators with influential variables developed from the geometry of four selected urban built forms. An urban energy simulation software package, CitySim, is adopted to conduct sensitivity analyses. The simulation models are validated against data from a known building group. An energy indicator, termed Energy Equity, is also introduced that simultaneously considers the amount of building energy demand as well as energy generation by building-mounted PVs. Cross case study analysis is undertaken to examine the impact of climate on urban energy performance, where four cities (London, Singapore, Helsinki and Phoenix) are chosen based on the specific climatic criteria. Meteonorm software is adopted to generate climate file relating to each case study. The investigation is further complemented by analysing future scenarios to examine the impact of climate change and technological developments (i.e

The study investigates the impact of climate on the residential building energy performance and its relationship with urban built form and geometry of the built environment. It aims to identify the most energetically sustainable urban built form and optimal urban geometry in different climates that results in higher energy performance of buildings. Geometrical models of four urban built forms are developed, and a simulation method is used to conduct sensitivity analyses over the four case studies (cities of London, Singapore, Helsinki and Phoenix) that are selected based on specific climatic criteria. The Energy Equity (EE) indicator is used for demonstration of the results, which simultaneously considers the amount of building energy demand as well as energy generation by building-mounted PVs. The results show that increasing the cut-off angle (i.e., reducing buildings distance) reduces building energy demand in cooling-dominated buildings (i.e., in Singapore and Phoenix) between 6% and 56% while increases building energy demand in heating-dominated buildings (i.e., in London and Helsinki) between 2% and 16.5%. Hence, the impact of distance between buildings on building energy demand is more significant in hot climates. In general, building energy demand in London is the lowest among the case studies, while it is the highest in Singapore (up to 219% higher than London). London also shows the highest value of EE (demonstrating the best energy performance) and Helsinki shows the lowest (up to 51% lower than London). It is recommended to use the tunnel-court built form to have a more energy-efficient buildings, specifically in hot climates.