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 cutoff 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 cutoff 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.

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This paper reviews the historical research that has led to widespread policies on compact urban form, in particular, residential development, and collates evidence that demonstrates that dispersed urban form may be more energy efficient than compact form. This is counterintuitive but is supported by both challenging the conventional modelling of energy use of buildings as well as case studies with empirical evidence. The conclusion is that policies on urban form should be driven not by existing technologies but by the disruptive technologies of the future. The increased use in distributed energy generation in urban areas (generally roof-mounted photovoltaics), the growth in ownership of electric vehicles and the potential introduction of smart and micro-grids and the possibility of virtual power plants is changing the impact that energy has on built form and conflicts with current policies for denser, contained and compact development.

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In order to optimize the energy consumption in cities and enhance the potential of using renewable energy sources, the form of the city is considered as an influential factor. Numerous indicators have been used to analyse the effect of density and other characteristics of urban form on energy use. The paper presents results of an investigation into the relationships of building energy performance with two important urban density indicators, namely site coverage and volume-area ratio. Generic mathematical model of pavilion urban built form has been developed in order to compare and contrast its land-use/density characteristics with energy performance. Energy analysis has been performed on geometrical models using urban simulation software. The relationship between energy and density indicators are compared by considering an important variables, namely plan depth, cut-off angle and number of storeys. The city of London, representing a temperate climate, is considered as a case study. According to the results, high-rise buildings with deeper plans achieve higher energy efficiency. However, in case of including PV energy generation, low-rise buildings with deeper plans illustrate better total energy performance. Graphical results provide urban planning guidelines that can be used by urban designers, planners and architects to facilitate the most energy-efficient built form density for promoting more sustainable cities.